C3, the third component of complement, can be activated by either antibody binding or by microbial polysaccharides.
SPI
Self-Paced Instruction
³H-uridine
³H-uridine is a radioactive form of the nucleoside uridine that has a radioisotope of the hydrogen atom embedded in its molecular structure. Uridine is a nucleoside component of RNA; thus, ³H-uridine is incorporated into RNA and can be measured to determine RNA synthesis.
Bacillus
Bacillus is a large genus of gram-positive, spore-bearing, rod-like bacteria. They are widely distributed in soil and air (usually as spores). Most feed on dead organic material and are responsible for food spoilage.
Escherichia coli
Escherichia coli is a species of bacteria that lives in the intestines of healthy humans and animals. It is generally not pathogenic, but the O157:H7 strain, transmitted through improperly prepared infected meat or contact with infected feces, produces a powerful toxin that can cause severe illness.
Lactobacillus
Leptotrichia
Leptotrichia is a genus of anaerobic, nonmotile bacteria containing Gram-negative, straight or slightly curves rods, 5 to 4 µm in length, with one or both ends rounded, often pointed. Granules are distributed evenly along the long axis, and one or more large granules may localize near the end of the cell. Branched or clubbed forms do not occur. Two or more cells may join together to form septate filaments of varying length. In older cultures, filaments up to 200 µm may form and twist around each other. These organisms occur in the oral cavity of man.
Neisseria
Neisseria is a genus of aerobic to facultatively anaerobic bacteria (family Neisseriaceae) containing Gram-negative cocci, which occur in pairs with the adjacent sides flattened. These organisms are parasites of animals.
Propionibacterium acnes
Propionibacterium acnes is a bacteria commonly found in acne pustules. Propionibacterium is a genus of non-motile anaerobic, gram-positive bacteria that are found on the skin of humans, in the intestinal tract of humans and animals, and in dairy products.
Rhodotorula rubra
Rhodotorula rubra is a common species of yeast, easily identified by its orange color and commonly found in air and water contaminants.
Serratia marcescens
Serratia is a genus of motile, gram-negative bacilli capable of causing infection in humans, including bacteremia, pneumonia and urinary tract infections. Serratia marcescens, the type species, is found in water, soil, milk, foods, silkworms and other insects.
Staphylococcus aureus
Staphylococcus aureus is a common bacterial species found on nasal mucous membranes and the skin (hair follicles). S. aureus causes pneumonia, endocarditis, and other infections, as well as food poisoning; it is also a main cause of infections in burn patients.
Veillonella
Veillonella is a genus of nonmotile, nonsporeforming, anaerobic bacteria (family Veillonellaceae) containing small (0.3 to 0.5 µm in diameter), Gram-negative cocci which occur as diplococci and in masses. Carbon dioxide is required for growth, and carbohydrates are not fermented. These organisms are parasitic in the mouth and the intestinal and respiratory tracts of man and other animals. They produce serologically specific endotoxins (lipopolysaccharides) which induce pyrogenicity and the Schwarzman phenomenon in rabbits.
1,25-dihydroxyvitamin D
Vitamin D acts in the body to increase calcium absorption from the gastrointestinal tract and also helps control calcium deposition in the bone. The natural vitamin D results from ultraviolet irradiation of a substance in the skin. This substance must then be converted to 1,25 dihydroxyvitamin D by the liver and kidneys to have an effect in the body.
1-G
1-G (one-G) refers to the gravity force found on Earth.
1-methylhydrazine
Methylhydrazine is a toxic compound primarily used as a high-energy fuel in military applications, as a rocket propellant and fuel for thrusters, and as fuel for small electrical power generating units.
15N-Glycine
15N-glycine is a nonradioactively labeled form of the amino acid glycine, which is found in protein. The nitrogen-15 (15N) isotope allows the concentration of glycine from a known source to be detected and measured in urine or saliva samples to evaluate protein metabolism.
15N-glycine method
The 15N-glycine method is used to measure the synthesis rate of protein in the body. Glycine is gelatin sugar composed of carbon, hydrogen, and nitrogen. Instead of the common 14N nitrogen isotope, the less common 15N isotope of nitrogen is used as part of the glycine molecule. 15N makes up about 0.365% of natural nitrogen. Glycine is digested by the body and part of the 15N is used to synthesize new protein molecules, while the unused nitrogen is excreted in the urine. The difference between the excreted and ingested amounts of 15N-glycine determines the synthesis rate for protein.
17-hydroxycorticosteroid
17-Hydroxycorticosteroid refers to any of the hormones, such as cortisol, secreted by adrenal glands and measured in the urine in a test for determining adrenal function and diagnosing hypo- or hyperadrenalism.
17-ketosteroid
17-Ketosteroid is a steroid containing a ketone group which is commonly measured in blood and urine to aid in the diagnosis of Addison's disease, Cushing's syndrome, stress and endocrine problems.
2,3-diphosphoglycerate (2,3 DPG)
2,3-diphosphoglycerate (2,3 DPG; now known as 2,3-biphosphoglycerate) is an important regulator for the affinity of hemoglobin for oxygen. It synthesizes within red blood cells (RBCs). This synthesis represents a major reaction pathway for the consumption of glucose in RBCs. Note that when glucose is oxidized by this pathway the RBC loses the ability to gain 2 moles of adenosine triphosphate (ATP) from glycolytic oxidation of 1,3-biphosphoglycerate to 3-phosphoglycerate via the phosphoglycerate kinase reaction. The synthesis of 2,3-biphosphoglycerate in RBCs is critical for controlling hemoglobin affinity for oxygen. It plays a major role in making adjustments in oxygen delivery, over a period of several hours to one day. Thus, it sets the level of oxygen delivery, ensuring that delivery remains sufficient and almost constant despite modest variations in oxygen availability.
3-methyl histidine
3-methyl histidine is an amino acid that is one of the constituents of the major proteins (actin and myosin) of skeletal muscle. It is excreted in the urine when actin and myosin are metabolized, and it is not used to form new protein. Therefore, the amount of 3-methyl histidine in urine is considered an indicator of muscle protein degradation.
3-methyl-d3-histidine
3-methyl-d3-histidine is a version of 3-methyl-histidine containing three atoms of deuterium (a stable isotope of hydrogen) in the methyl group. 3-methyl-d3-histidine is used as a tracer to follow the path of muscle protein degradation in the body.
3H-methyl-thymidine
3H-methyl-thymidine is a thymidine molecule, one of four “code” substances in deoxyribonucleic acid (DNA), made radioactive by substituting tritium (3H) for ordinary hydrogen (1H).
A
Amperes
A&E
Architectural and Engineering
A&R
Automation and Robotics
A-D
Analog to Digital
A-E
Activity Elements
A-G
Air-To-Ground
A-L
Airlock
A-V
Analog-Video
A/C
Aircraft
A/D
Analog to Digital
AA
Air to Air
AA
Associate Administrator (NASA)
AA-OSS
Associate Administrator - Office of Space Science
AAHF
Aquatic Animal Holding Facility
Aberration
Aberration refers to straying from the normal situation; deviant development or growth.
ABS
Animal Biotelemetry System
Abscess
An abscess is a circumscribed collection of pus appearing in an acute or chronic localized infection, and is associated with tissue destruction and swelling.
Absolute Lymphopenia
Absolute Lymphopenia is the reduction in the total number of lymphocytes in the blood.
Absolute Neutrophilia
Absolute Neutrophilia refers to the increase in the total number of leukocytes in the blood as well as an increased percentage of neutrophils.
Absorbed dose
An absorbed dose is the quantity of radiation received per unit of mass within a given period of time. The unit is the gray (Gy), although it is often measured in rads (1 rad = 0.01 gray).
Absorptance
Absorptance is the ratio of absorbed to incident radiation.
Absorptiometer
An absorptiometer is a device that measures photon radiation. An absorptiometer consists of at least three essential components: (1) a source of electromagnetic (photon) radiation in the proper energy region, (2) a cell that is transparent to the radiation and that can contain the sample, and (3) a detector that can accurately measure the intensity of the radiation after it has passed through the cell and the sample.
Absorptiometry
Absorptiometry is a technique that measures the amount of radiation absorbed by any substance or chemical constituent of blood, urine or other body fluid that is analyzed (analyte). Essentially, the amount of absorbed radiation increases with the concentration of the analyte and with the distance through the analyte that the radiation must travel (the cell path length). As radiation is absorbed in the sample, the intensity of the radiative beam decreases. By measuring the decreased intensity through a fixed-path-length cell containing the sample, it is possible to determine the concentration of the sample. Because different analytes absorb at different wavelengths (or energies), the device that measures the radiation must be capable of controlling the wavelength of the incident electromagnetic (photon) radiation. When measuring bone mineral content, the radiation sources used emit radiation within a narrow wavelength band.
Absorption
Absorption is the uptake of fluids or other substances by the tissues of the body. Digested food is absorbed into the blood and lymph from the alimentary canal. Most absorption of food occurs in the small intestine.
AC
Alternating Current
ACA
Attitude Control Assembly
Acceleration
Acceleration is the rate of change of velocity with respect to time.
Accelerometer
An accelerometer is a device used to measure acceleration, the rate of change of velocity with respect to time.
Accessory cell
An accessory cell is a blood cell, usually a monocyte, that secretes a substance (such as interleukin-1) required for activation of lymphocytes in the immune response.
ACCU
Audio Central Control Unit
ACD
Architectural Control Document
Acetaminophen
Acetaminophen is a medication commonly used to reduce pain or fever.
Acetylcholine
Acetylcholine is released at nerve endings to pass on a nerve impulse to the next nerve or to initiate muscular contractions. The released acetylcholine is rapidly broken down by the enzyme acetylcholinesterase to allow the transmission of following (subsequent) impulses.
Acetylcholinesterase
Acetylcholinesterase is an enzyme that breaks down the neurotransmitter acetylcholine (a chemical which initiates muscular contraction) into choline and acetic acid, rendering it inactive or unable to transmit a signal, therefore, stopping or regulating the nerve signals.
Acetylene (C2H2)
Acetylene is a colorless, odorless hydrocarbon gas. Its formula is C2H2, and in high concentration of 40 volumes per cent and higher it has the effect of an anesthetic.
Acetylene concentration
Acetylene is a colorless explosive hydrocarbon gas, and is used as an anesthetic in concentrations of 40 volumes per cent and higher.
ACF
Animal Care Facility
ACGIH
American Conference of Government Industrial Hygienists
Achilles tendon
The Achilles tendon is a fibrous band that connects the triceps surea (the calf muscle) with the calcaneus (heel bone).
Acid citrate dextrose
Acid citrate dextrose contains trisodium citrate (dihydrate), citric acid and glucose. It is an anticoagulant agent that keeps blood from clotting, or forming into a solid or gel.
Acid phosphatase
Acid phosphatase is an enzyme with acidic pH optimum, that catalyzes cleavage of inorganic phosphate from a variety of substrates. Found particularly in lysosomes and secretory vesicles. Can be localized histochemically using various forms of the Gomori procedure.
Acinetobacter calcoaceticus bio. anitratus
Acinetobacter calcoaceticus bio. anitratus is a species of bacteria originally found in environments containing quinic acid. It is a nonmotile, aerobic bacterium in the form of gram-negative short rods and does not produce spores. One of its strains is commonly found in the genitourinary tract of humans.
Acini
Acini are the small gas exchange regions of the lung.
Acoustic
Acoustic means of or relating to sound, the sense of hearing or the science of sound.
ACPL
Atmospheric Cloud Physics Lab
ACR
Active Cavity Radiometer
ACS
Aft Crew Station
ACS
Attitude Control System
ACT
Actual
Actifed
Actifed is a trademark for a fixed-combination drug containing an adrenergic vasoconstrictor and an antihistamine.
Actinometry
Actinometry is used to measure the ability of radiant energy in the visible and ultraviolet spectral regions to produce chemical changes. Actinometry can also measure the direct heating power of the sun's rays.
Action potential conduction velocity
The action potential conduction velocity is the measure of the velocity of a nerve impulse (or action potential) from a specified initial point to an end point on a nerve fiber. The change in voltage that occurs across the membrane of a nerve or muscle cell when a nerve impulse is triggered is called an action potential; it is caused by the passage of charged particles across the membrane (depolarization).
Activate
To activate is to set in motion; to make active.
ACTP
Acceptance and Certification Test Plan
Actuator
An actuator is a mechanical device used to move or control an object.
ACUC
Animal Care and Use Committee
Acuity
Acuity is clarity or distinctness of hearing or sight.
Ad libitum
Ad libitum means without restraint.
ADC
Analog Digital Converter
ADCLS
Automated Data Collection/Location System
Adductor
An adductor is any muscle that draws a body part toward the median plane of the body.
Adductor longus
The adductor longus is one muscle of the inner thigh. It is the muscle that allows the thigh bone (femur) to move.
Adenosine monophosphate (AMP)
Adenosine monophosphate (AMP), more specifically known as adenosine-5'-monophosphate or adenylic acid, functions as the basic structure for ATP and ADP, both of which serve as short term energy stores for the cell.
Adenosine triphosphatase (ATPase)
Adenosine triphosphatase (ATPase) is an enzyme that hydrolyzes adenosine triphosphate.
Adenosine triphosphate (ATP)
Adenosine triphosphate (ATP) is a nucleotide that is of fundamental importance as a carrier of chemical energy in all living organisms. ATP can undergo hydrolysis, a reaction triggered by ATPase, which releases a large amount of energy that is used to fuel such biological processes as muscle contraction or the active transport of ions and molecules across cell membranes, or the synthesis of biomolecules.
Adenovirus
Adenoviruses are viruses containing double-stranded DNA. They cause latent infections in mammals and birds of the upper respiratory tracts, and produce symptoms resembling those of the common cold.
ADM
Archive Data Manager
ADP
Acceptance Data Package
ADP
Automatic Data Processing
ADR
Ames Double Rack
Adrenal
Adrenal means near or upon the kidney; denoting the adrenal glands (a pair of endocrine glands) located on the surface of the kidneys. These glands are responsible for the secretion of adrenalin and other regulatory hormones.
Adrenal cortex
The adrenal cortex is the outer region of the adrenal gland, in which several steroid hormones are produced.
Adrenal glands
Adrenal glands are a pair of endocrine glands located on the surface of the kidneys that are responsible for the secretion of adrenalin and other regulatory hormones.
Adrenalectomized
Adrenalectomized (or adrenalectomy) means having one or both adrenal glands removed.
Adrenergic
Adrenergic means activated by, characteristic of, or secreting epinephrine (adrenaline) or substances with similar activity. The term is applied to nerve fibers that liberate epinephrine at a synapse when a nerve impulse passes, such as the sympathetic fibers.
Adrenergic receptors
Adrenergic receptors are receptors of nerve cells or fibers of the nerve systems that employ norepinephrine or epinephrine as their neurotransmitter (to transmit a signal from one nerve cell to the next).
Adrenocortical
Adrenocortical means of, relating to, or derived from the cortex of the adrenal glands.
Adrenocorticotropic hormone (ACTH)
Adrenocorticotropic hormone (ACTH) is a hormone synthesized and secreted by the anterior pituitary gland. ACTH is produced in response to stress and controls the secretion of certain hormones by the adrenal glands.
ADSF
Advanced Directional Solidification Furnace
ADT
Abstract Data Type
AEI
Analytical Experiment Integration
AEM-II
Animal Enclosure Module - Mark II
AEPI
Atmospheric Emission Photo Imaging
Aerobic
Aerobic means living in air. Aerobic can also describe a type of cellular respiration in which foodstuffs (usually carbohydrates) are completely oxidized into carbon dioxide and water with the production of chemical energy, in a process requiring atmospheric oxygen.
Aerobic (exercise) capacity
Aerobic capacity, or aerobic exercise capacity, is the capacity of the respiratory and cardiovascular systems to deliver oxygen to working muscles.
Aerodynamic size
Aerodynamic size is the size of a particle when it is moving through air.
AF
Audio Frequency
AFB
Air Force Base
AFC
Automatic Frequency Control
AFD
Orbiter Aft Flight Deck
Afebrile
Afebrile means without fever.
Afferent
Afferent is a general term applied to nerves or blood vessels that means nerve signals or blood are traveling from the peripheral to the center of the body.
AFOS
Automation of Field Operations and Services
AFT
Aerodynamic Flight Test
AFTE
Autogenic Feedback Training Experiment
Agar
Agar is an extract of certain seaweeds that forms a gel suitable for the solidification of liquid bacteriological culture media.
AGC
Automatic Gain Control
Agglutinate
Agglutinate means to cement or unite together.
Agglutination
Agglutination is the clumping or sticking together of cells, such as red blood cells or bacteria, so that they form a visible pellet-like clump. Agglutination can be a reaction of the red blood cells, closing an injury in the skin, or by antibodies.
Aggregate
An aggregate is a group of cells that are attached together.
Aggregation
Aggregation means to unite or come together in a mass or cluster.
Agonist
Agonist describes a drug, hormone or transmitter substance that forms a complex with a receptor site and triggers an active response from a cell (in other words, a drug capable of initiating actions is an agonist). Also, an agonist is a muscle whose active contraction causes movement of a part of the body.
AGS
Antigravity Suit
AGSIEI
Anti-G Suit Inflight Evaluation Instrumentation
AI
Action Item
AI
Analog Input
AI
Artificial Intelligence
AI&T
Assembly, Integration and Test
AIBS
American Institute of Biological Sciences
AICS
Action Item Control System
AIL
Authorized Inventory List
AL
Accelerator
AL
Airlock
Alanine
Alanine is a nonessential amino acid found in many food protein sources as well as in the body.
Albumin
Albumin is a type of simple protein widely distributed throughout the tissues and fluids of plants and animals; it is characterized by being soluble in water but forms insoluble coagulates when heated. Albumins occur in egg white, blood, milk, and plants.
Aldosterone
Aldosterone is the principal electrolyte-regulating steroid secreted by the adrenal cortex; it controls excretion of potassium by the kidneys and thereby maintains the balance of sodium and water in the body fluids.
ALFE
Astronaut Lung-Function Experiment
Algorithm
An algorithm is any mechanical or repetitive procedure used in the management of health problems.
Aliquot
An aliquot is a portion of the whole. When a sample is separated into aliquots, each portion is of equal weight or volume.
Aliquote
Aliquote (verb) is to divide into equal portions.
Alkaline phosphatase
Alkaline phosphatase is an enzyme that catalyses the hydrolysis of phosphoric acid esters under conditions of alkaline pH. In humans, the level of alkaline phosphatase in the blood is measured as part of the assessment of liver function. In the blood, the enzyme also breaks down phosphates required for mineralization of bone. There are two distinct forms of the enzyme, liver alkaline phosphatase and bone alkaline phosphatase.
Alkalosis
Alkalosis is an abnormal condition of body fluids, characterized by a tendency toward a pH level greater than 7.44, usually caused from an excess of alkaline bicarbonate or a deficiency of acid. Respiratory alkalosis may be caused by hyperventilation, resulting in an excess loss of carbon dioxide and a carbonic acid deficit. Metabolic alkalosis may result from an excess intake of or retention of bicarbonate, loss of gastric acid in vomiting, potassium depletion or any stimuli that increases the rate of sodium-hydrogen exchange.
Allantoic fluid
Allantoic fluid is fluid of the allantois, a fetal membrane developing from the hindgut (or yolk sac, in man). In man the allantois is vestigial; in mammals it contributes to the formation of the umbilical cord and placenta, and in birds and reptiles it lies close beneath the porous shell and serves as an organ of respiration.
Allergen
An allergen is any anitigen that causes allergy in a hypersensitive person. Allergens are diverse and affect different tissues and organs. Examples of allergens include pollen, fur, feathers, dust and mold.
Alloy
An alloy is composed of a mixture of two or more metals.
Alpha globulin
An alpha globulin is a type of protein present in plasma. Alpha globulins perform diverse functions in the circulation, such as transporting various substances by combining reversibly with them, transporting other proteins from within the body, and acting as substrates for the formation of other substances.
Alpha particle
An alpha particle (alpha radiation) is a positively charged particle ejected spontaneously from the decay of some radioactive elements. It is identical to the nuclei of ordinary helium atoms with two protons bound to two neutrons. Alpha particles have low penetrating power and a short range (a few centimeters in air). The most energetic alpha particle will generally fail to penetrate the dead layers of cells covering the skin and can be easily stopped by a sheet of paper. Alpha particles are hazardous when an alpha-emitting isotope is inside the body.
Alpha-1-antitrypsin
Alpha-1-antitrypsin, a glycoprotein, is a major protease inhibitor of human serum and is produced in the liver. It protects tissues from digestion and blocks the action of target enzymes by binding nearly irreversibly to their active site.
Alpha-glycerophosphate dehydrogenase (GPD)
Alpha-glycerophosphate dehydrogenase (GPD) is an enzyme, found in muscle cell cytoplasm, that is involved in the synthesis of adenosine triphosphate.
Alternaria is a genus of fungi easily isolated from air that is considered to be a common laboratory contaminant and an allergen; it is occasionally pathogenic in humans.
Alternate Payload Specialist
Many Shuttle-Spacelab missions have assigned alternate payload specialists. The alternate payload specialists receive the same training as the flight payload specialists. Until one month before flight, the alternate payload specialist acts as a backup and can replace the flight payload specialist, if necessary. During the mission, the alternate payload specialists will remain on the ground (unless they replace the primary crewmember) and act as the prime communicator with the payload crew in space.
Altitude
Altitude refers to the height above sea level of a given point.
ALU
Advanced Levitation Unit
Alveolar
Alveolar refers to alveoli, air sacs of microscopic size in the lung whose function is to facilitate the exchange of oxygen and carbon dioxide from the air to blood.
Alveolar bone
In dentistry, alveolar bone (also called alveolar supporting bone) denotes the specialized bone structure, which supports the teeth.
Alveolar epithelium
The alveolar epithelium is the tissue that covers the external surface of the alveoli (air sacs of microscopic size in the lung whose function is to facilitate the exchange of oxygen and carbon dioxide from the air to blood).
Alveolar gas pressure
Alveolar gas pressure is the pressure within the alveoli, the smallest gas exchange units of the lung. Alveolar pressure determines whether air will flow into or out of the lungs. When alveolar pressure is negative, air is taken into the lungs. When alveolar pressure is positive, air is exhaled.
Alveolar ventilation (VA or V(A))
Alveolar ventilation is the passage of air into and out of the alveoli (microscopic sacs in the lungs wherein gas exchange occurs).
AM
Amplitude Modulation
Ambient (AMB)
Ambient describes the conditions and factors in the immediate environment. For example, the ambient temperature is the local temperature. The term is also used to describe room temperature (20 degrees Celcius, 70 degrees Fahrenheit).
Amino acid
Amino acids are the building blocks of protein. Amino acids join together and form short chains (peptides) or much longer chains (polypeptides). Over 80 amino acids are known to occur naturally,with 20 found commonly in protein polypeptides.
AMM
Ames Management Manual
Amperometry
Amperometry is measurement of electrical current.
Amphibian
An amphibian is an organism, such as a frog, toad, salamander, or some types of newts, having an aquatic early stage (e.g. tadpole) and developing air-breathing lungs as an adult (e.g. frog).
Amplitude
Amplitude is a measure of the distance between the high and low points of a waveform.
Ampoule
An ampoule is a small glass vial sealed after filling (chiefly used as a container for a hypodermic injection solution).
AMR
Advanced Microwave Radiometer
AMS
Altitude Measurement Systems
AMS
Attitude Measurement Sensor
AMSU
Advanced Microwave Sounding Unit
AMU
Automatic Mass Unit
Amylase
Amylase is an enzyme that occurs in saliva and pancreatic juice and aids the digestion of starch and other polysaccharides, which it breaks down into glucose, maltose and dextrins.
Amyotrophy
Amyotrophy is muscular wasting or atrophy.
AN
Alteration Notice
Anabolism
Anabolism is the metabolic process by which simple substances are synthesized into the complex materials of living tissue.
Anaerobe
An anaerobe is a microorganism that grows and lives in the complete or almost complete absence of oxygen.
Anaerobic
Anaerobic refers to an environment or a condition which is free of oxygen or describes a microorganism which can grow in the absence of oxygen.
Analog
An analog transmission mode is one in which data is represented by a continuous electronic signal. In an electronics system, analog, often referred to as linear, refers to measuring a continuous stream of varying voltage levels.
Analysis of variance (ANOVA)
ANOVA, or analysis of variance, is a statistical technique for investigating sets of measurements to determine the extent of experimental or chance influences on individual measures.
Androsterone
Androsterone is a steroid metabolite found in male urine and having weak androgenic potency.
Anemia
Anemia is a condition characterized by oxygen carrying deficiency caused by a low amount of red blood cells, iron deficiency, or sickle cell formation of red blood cells.
Anemostat
An anemostat is a device used to regulate the force or speed of air flow, such as by controlling the speed of an electrical fan unit.
Aneroid
Aneroid means without liquid, such as a mercury-free pressure gauge used with some sphygmomanometers.
Angiotensin
Angiotensin is a family of vasoconstrictor substances (which causes narrowing of the blood vessels), present in the blood; it is formed by the action of renin upon a globulin formed by the liver and helps regulate blood pressure.
Angular velocity
Angular velocity is rotation rate, the rate of change of angular displacement.
Animal Enclosure Module (AEM)
The Animal Enclosure Module (AEM) is designed to house up to 16 rats on the Shuttle. The animals can be monitored through the plexiglass ceiling of the module.
Anion
An anion is a negatively charged ion.
Ankle dorsiflexor
The ankle dorsiflexor (tibialis anterior) is the calf muscle which causes the foot to turn upward.
Annotation
Annotation is a critical or explanatory note; a commentary.
Anode
An anode has a negative electrical load; all positive loaded ions move towards the anode.
Anodize
By electrolytic action, anodyze is the process of coating or plating a metal (usually aluminum) with a protective material.
Anomaly
An anomaly is a deviation from the common rule; an irregularity.
Anoxia
Anoxia is an abnormal condition characterized by a lack of oxygen. Anoxia may be local or systemic and may be the result of an inadequate supply of oxygen to the respiratory system or of an inability of the blood to carry oxygen to the tissues, as in anemic anoxia, or an inability of the tissues to absorb the oxygen from the circulating blood, as in histotoxic anoxia.
ANSI
American National Standards Institute
Antagonist
An antagonist refers to a muscle in a passive state, while the opposing muscle, the agonist, is active.
Antecubital
Antecubital means pertaining to the area inside the elbow.
Antecubital fossae
The antecubital fossae is the front area where the arm bends at the elbow.
Antenna
An antenna is a metallic instrument used for transmitting and receiving electronic signals.
Anterior
Anterior describes or relates to the front (or ventral) portion of the body, an organ or the limbs.
Anterior horns
Anterior horns are the inner substance of the human brain, or the gray matter. The gray matter builds two "horns"; the one pointing toward the face is called the anterior horn, the one facing towards the neck is called the posterior horn.
Anthropometric
Anthropometric means of or relating to anthropometry, the branch of anthropology concerned with comparative measurements of the human body. In space flight, for instance, the length of the spinal column is measured before and during flight to determine if the vertebrae expand in space.
Anthropometry
Anthropometry is the study of anthropometrics. Anthropometry is a branch of anthropology (the science of studying humans in all their relations), that deals with making comparative measurements of the human body. In space flight, for instance, the length of the spinal column is measured before and during flight to see if the vertebrae expand in space.
Antibiotic
An antibiotic is a substance, produced by or derived from a microorganism (especially mold), that destroys or inhibits the growth of other microorganisms. Antibiotics are used to treat infections caused by organisms that are sensitive to them, usually bacteria or fungi.
Antibody
An antibody is a special blood protein secreted by B-lymphocytes, a type of white blood cell in the immune system. Antibodies are synthesized in response to the presence of a particular antigen (foreign or potentially dangerous substances, such as bacteria and viruses). Antibodies circulate in the bloodstream and bind to the antigen rendering it harmless. White blood cells then recognize the antibodies and destroy the foreign object.
Antibody titer
An antibody titer is a measure of antibody quantity.
Anticipatory postural activity
Anticipatory postural activity describes the reflexes which prevent the body from falling to the ground in the event of an unexpected lean that sends the body out of balance. These reflexes activate the muscles before the brain can react to the change the posture. People who don’t have good anticipatory postural reflexes are more likely to fall over if they are suddenly pushed.
Antidiuretic Hormone (ADH)
Antidiuretic Hormone (ADH) is a hormone (also called vasopressin) produced and released in the posterior pituitary gland. It stimulates the kidneys to absorb water from produced urine, thus controlling the water content of the body.
Antigen
An antigen is any substance that the body regards as foreign and which therefore triggers an immune response; antigens are usually proteins associated with bacteria and viruses.
Antigenic
Antigenic means allergenic or having the properties of an antigen.
Antigravity muscle
The antigravity muscles, located in the legs, trunk and neck, function primarily to support the body against the pull of gravity; the relative degree of contraction of the individual antigravity muscles is determined by the equilibrium mechanisms, which are controlled by signals mainly from the vestibular apparatuses (sensory organs for equilibrium).
Antigravity suit (G-suit, pressure suit)
An antigravity suit or pressure suit is a garment worn by space travelers during launch and/or landing. It exerts pressure, usually by means of inflatable air bladders, on the thighs and abdomen to lessen the pooling of blood in the lower part of the body during acceleration.
Antihypotensive
Antihypotensive means of or pertaining to a substance or procedure that increases low blood pressure.
Antioxidant
An antioxidant is a substance that slows or prevents oxidation reactions, and is commonly added to prepared foods, vegetable oils and paints to prevent deterioration upon exposure to oxygen.
Antipyrine
Antipyrine is a substance used to reduce fever.
Antisera
Antisera is serum containing immunoglobulins against specific antigens.
AO
Announcement of Opportunity
AOA
Abort-Once-Around
AOD
Assistant Operations Director
AOQL
Average Outgoing Quality Limit
Aorta
The aorta is the main artery of the body from which all others derive; it arises from the left ventricle of the heart, arches over the top of the heart and descends in front of the backbone, giving off large and small branches and finally dividing to form the right and left iliac arteries in the legs.
AOS
Acquisition of Signal (Telemetry)
AP
Active Package
AP
Geomagnetic Activity Index
APA
American Planning Association
APAE
Attached Payload Accommodation Equipment
Aperture
Aperature is an adjustable opening in an optical instrument that limits the amount of light passing through a lens.
Apex
An apex is the extremity of a conical or pyramidal structure.
Apical
Apical means situated at the uppermost point.
Apical dendrite
A dendrite is the slender branching process that arises from the dendrons of the nerve-cell body. A dendrite forms connections with the axons of other neurons and transmits nerve impulses. An apical dendrite is situated nearer the apex of a neuron.
APM
Antenna Pointing Mechanism
Apneic
Apneic means related to or suffering from apnea, the transient cessation of breathing or a lack of oxygen.
APP
Approved
APP
Astrophysics Payloads
APS
American Physiological Society
APS
Auxiliary Power Subsystem
APT
Advanced Propulsion Test
APT
Automatic Picture Transmission
APU
Auxiliary Power Unit
AQL
Acceptance Quality Level
AR
Acceptance Review
Arachidonic acid
Arachidonic acid is a component of cell membranes released on their injury; forms mediators of inflammation (prostaglandins and leukotrienes).
ARC
Ames Research Center
Archival sampling
Archival sampling is the storage of samples or data by an automated sampling device.
ARCLSFEP
Ames Research Center Life Sciences Flight Experiments Program
ARCLSP
Ames Research Center Life Sciences Payload
Arcuate nucleus
The arcuate nucleus (arcuatus) is a cell group in the hypothalamus, located in the lowest part of the infundibulum adjacent to the median eminence; it is involved in neuroendocrine control through the release of releasing hormones and inhibitory hormones.
ARINC
Aeronautical Radio Incorporated
Arrhythmia
An arrhythmia is any deviation from the normal rhythm of the heart.
ARS
Atmospheric Revitalization Section
ARS
Atmospheric Revitalization Subsystem
Arterial
Arterial means of or relating to arteries. Arteries are blood vessels that carry oxygenated blood from the heart to the rest of the body with the exception of the pulmonary artery, which carries unoxygenated venous blood from the heart to the lungs.
Arterial pressure
Arterial pressure is the pressure of the blood on the walls of the arteries, dependent on the energy of the heart action, the elasticity of the walls of the arteries, and the volume and viscosity (resistance) of the blood.
Arterial-alveolar carbon dioxide difference
The arterial-alveolar carbon dioxide difference is the difference or gradient between the partial pressure of carbon dioxide in the alveolar spaces and the arterial blood. In young adults, the value is normally less than 48.
Arteriovenous
Arteriovenous means relating to both arteries and veins in general.
Arteriovenous oxygen difference
The arteriovenous oxygen difference is the arterial oxygen content minus the central venous oxygen content.
Artery
An artery is a blood vessel that carries oxygenated blood from the heart to the tissues and form part of the circulatory system. All arteries except the pulmonary artery carry oxygenated blood.
Arthropod
An arthropod is any segmented invertebrate of the phylum Arthropoda, having joined legs and including the insects, arachnids (spiders), crustaceans, and myriapods.
Artifact
An artifact is any object made or modified by man. In a scientific investigation, an artifact is a false result or effect caused by the introduction of unintended substances or structures.
ARU
Accelerometer Recording Unit
ASAHF
Advanced Small Animal Holding Facility
ASCG
Automatic Solution Crystal Growth
ASCIE
American Standards Code for Interface & Exchange
ASCII
American Standard Code for Information Interchange
Ascomycetes
Ascomycetes, has a single nucleus, and reproduces either asexually by budding or fission, or sexually through spore formation.
Ascorbic acid
Ascorbic acid, an antioxidant, is an effective reducing agent that retards oxidation, the process by which substances combine with oxygen in the air at room temperature.
ASCS
Atmosphere Storage and Control Section
ASCU
American Standard Computer Unit
ASD
Avionics Systems Division
ASE
Airborne Support Equipment
Aseptic
Aseptic means a condition in which living pathogenic organisms are absent; a state of sterility.
Aseptic technique
The aseptic technique is a manipulation of sterile instruments or culture media in such a way as to maintain sterility.
ASHRAE
American Society of Heating, Refrigeration, and Air conditioning Engineers
ASI
ASI is the abbreviation for the Italian space agency, Agenzia Spaziale Italiana, which is headquartered in Rome, Italy.
ASL
Approved Source List
ASM
Assistant Payload Science Manager
ASME
American Society of Mechanical Engineers
ASO
Advanced Solar Observatory
Aspergillus
Aspergillus is a genus of fungi that contains many black, brown, or green spored species. A few species are pathogenic to man, animals and birds.
Aspergillus species
Aspergillus species is a common genus of fungi that contains many different species. All Aspergillus species form black, brown or green spores in form of a sphere on the tip of a hypha. A few species are pathogenic for humans, other mammals and birds.
ASR
Ames Single Rack
Assay
An assay is the analysis of a substance or mixture to determine its constituents or their level. In Life Sciences, it is also the estimation of strength of a drug or substance by comparing its effects in test animals to a reference standard.
Atmosphere is a gaseous envelope surrounding a celestial body, especially that surrounding the Earth, which is retained in place by the force of gravity.
Atmospheric
Atmospheric relates to the environment or surroundings that have a physiological, physical or other influence.
Atmospheric drag
Atmospheric drag is a condition that occurs in the earth’s atmosphere which can accelerate an orbiting body.
Atmospheric physics
Atmospheric physics is the science of the physics of the atmosphere, including the components and layers of the atmosphere.
ATN
Astrophysical Teletype Network
ATO
Abort-to-Orbit
ATR
Acceptance Test Review
Atrial Natriuretic Factor (ANF)
Atrial natriuretic factor (ANF) is a hormone-like substance present in the two atrial walls of the heart (especially numerous in the right atria). ANF can cause a three to ten times increase in renal (kidney) excretion of sodium when it is fully released into the circulating blood. Consequent to the loss of sodium is a slight decrease in the extracellular fluid volume and blood volume. Although its exact mechanism of action is unclear, it is believed that the ANF plays a role in the regulation of blood volume.
Atrial natriuretic factor (ANF) receptors
Atrial natriuretic factor (ANF) receptors are a group of cells specialized to detect changes in the blood pressure. They are located within the atrial walls of the heart. Although the mechanism of the action of ANF receptors is not completely understood, it is believed that when excess blood volume stretches the atrial walls, ANF receptors located in the walls are triggered to release atrial natriuretic factor into the circulating blood. The ANF causes sodium (and water) to be excreted from the kidneys and blood volume to be reduced.
Atrial Natriuretic Peptide (ANP)
Atrial natriuretic peptide (ANP), also called atrial natriuretic factor (ANF), is a hormone-like substance present in the two atrial walls of the heart (especially numerous in the right atria). ANP can cause a three to ten times increase in renal (kidney) excretion of sodium when it is fully released into the circulating blood. Consequent to the loss of sodium is a slight decrease in the extracellular fluid volume and blood volume. Although its exact mechanism of action is unclear, it is believed that the ANP plays a role in the regulation of blood volume.
Atrial natriuretic peptide (ANP) receptors
Atrial natriuretic peptide (ANP) receptors are cell membrane bound molecules in the kidney's tubules which bind to atrial natriuretic peptide and promotes natriuresis, the excretion of sodium.
Atrioventricular dissociation
Atrioventricular dissociation is defined as the independent beating of the atria and ventricles.
Atrophy
Atrophy is the wasting away of a normally developed cell, tissue or organ. This may occur through undernourishment, disuse, aging or other mechanisms. For example, in space medicine muscle atrophy is the reduction of muscle mass resulting from disuse of the muscles.
Attenuation
Attenuation is the reduction of the disease-producing ability (virulence) of a microorganism. It can be achieved by chemical treatment, heating, drying, irradiation, by growing under adverse conditions, or by passing through another organism. Attenuated bacteria or viruses are used for some vaccines.
Attitude
Attitude is the nose up or nose down orientation of an aircraft's or spacecraft's axes relative to a reference line, plane or direction of motion.
Audible
Audible means a noise or sound which is capable of being heard.
Audiogram
An audiogram is the graphic record drawn by an audiometer, which charts the threshold of hearing at various frequencies against sound intensity in decibels.
Audiogram
An audiogram is a record of an individual's threshold of hearing at different sound frequencies.
Auditory canal
The auditory canal is the tube which extends from the opening of the ear to the tympanic membrane.
Aurelia
An aurelia is a type of jellyfish known as "moon" jellyfish. They are found in the waters of the Atlantic Ocean and the Chesapeake Bay on the eastern coast of the North American continent.
Auricle
The auricle is the outer portion of the ear. It is made out of cartilage and its function is to channel sound waves into the ear tube.
Autoflora
Autoflora refers to the microbial inhabitants of an individual.
Autogenic
Autogenic refers to something that is produced independently of external influence or aid.
Autogenic feedback training (AFT)
Autogenic feedback training is a method that can be taught to people to control motion sickness symptoms by using biofeedback techniques instead of drugs. Biofeedback provides immediate information about involuntary bodily functions to the individual, including nausea, heart rate and body temperature thus reducing motion sickness.
Autogenous
Autogenous means originating within the body.
Autoinfection
An autoinfection is reinfection of a host by microbes or parasitic organisms on or within the body that have already passed through an infective cycle, such as a succession of boils.
Autonomic function
An autonomic function is a function that is independent or self-controlling.
Autonomic nervous system (ANS)
The autonomic nervous system is the part of the nervous system that supplies stimulation to the involuntary muscles, such as the smooth and cardiac muscles, and to the glands. The autonomic nervous system is controlled principally by parts of the brain stem and the hypothalamus (a part of the brain).
Autoradiography
Autoradiography is an experimental technique in which a radioactive specimen is placed close to a photographic plate, so as to produce a record of the distribution of radioactivity in the specimen. The film is darkened by the ionizing radiation from radioactive parts of the sample. Autoradiography is used to study the distribution of particular substances in living tissues and cells. A radioactive isotope of the substance is introduced into the organism or tissue, which is killed, sectioned, and examined after enough time has elapsed for the isotope to be incorporated into the substance.
AUX
Auxiliary
Auxins
Auxins are hormone-like chemicals that induce cellular growth in plants.
AV
Audio Visual
AVCG
Automatic Vapor Crystal Growth
AVHRR
Advanced Very High Resolution Radiometer
Avionics
Avionics is the science and technology of electronics applied to aeronautics and astronautics.
AWG
American Wire Gauge
AWS
Air Weather Service
AWS
American Welding Society
AXAF
Advanced X-ray Astronomy Facility
Axilla
The axilla is the armpit or an analogous part.
Axillary
Axillary means pertaining to the armpit.
Axisymmetrical
Axisymmetrical refers to like, or same, conditions on both sides of a body axis; a straight line about which a body or a geometric figure rotates.
AZ
Azimuth
B&W
Black & White
B-lymphocyte
B-lymphocytes (B-cells) are white blood cells, one of two major types of lymphocytes (the other being T-lymphocytes, or T-cells). B-cells develop in the bone marrow, then migrate to various parts of the body via the bloodstream. By producing and secreting immunoglobulins (antibodies) in response to antigens, B-cells are the basis of the body's humoral immune system .
B/S
Bits per Second
BAC
Boeing Aerospace Company
Bacilli
Bacilli are rod-shaped bacteria.
Background 15N
Background 15N is an isotope of nitrogen which is present in the human body in low concentrations (about 0.365%) at all times. The naturally present 15N is referred to as background 15N.
Bacteria
Bacteria refers to a group of microorganisms which consist of only a single cell that lacks a distinct nuclear membrane and has a cell wall of unique composition. Bacteria are largely responsible for decay and decomposition of organic matter.
Bactericidal
Bactericidal is causing the death of bacteria.
Bacteriological
Bacteriological means relating to bacteria.
Bacteriology
Bacteriology is the scientific study of bacteria.
Bacteriophage
A bacteriophage is a virus that infects a bacterium or prokaryotes.
Bacteriorhodopsin
Bacteriorhodopsin is a carotenoid (naturally occurring pigment found mostly in plants) analogous to rhodopsin, the pigment of the animal eye, which functions in vision. Bacteriorhodopsin is able to absorb light and generate a proton gradient across the membrane of halobacterium (a microbe), leading to ATP synthesis without the involvement of chlorophyll.
Bacteriotherapy
Bacteriotherapy uses bacteria in the treatment of or control of disease; particularly intestinal diseases.
Bacteroid
A bacteroid is a microbe that resembles bacteria in shape or action.
Ballistic
Ballistic refers to the science of projectiles. Before the development of spacecraft capable of orbiting the Earth, ballistic missiles were launched. These missiles reached an environment of microgravity but followed a ballistic trajectory, still influenced by the Earth's gravity and atmospheric friction.
Barcode
A barcode is a label consisting of coded lines and spaces of different thicknesses (and sometimes numerals). It can be scanned by a barcode reader to provide information about the item on which it is found.
Barium
Barium is a metallic, alkaline, divalent earth element (atomic number 56, atomic weight 137.327). Salts of this element are often used in diagnostic tests.
Barophysiology
Barophysiology is the study of the effects of air pressure on the body's physiology.
Baroreceptor
A baroreceptor is a collection of sensory nerve endings specialized to monitor changes in blood pressure. The main receptors lie in the carotid sinuses and the aortic arch. Others are found in the walls of other large arteries and veins and some within the walls of the heart. Impulses from the receptors reach centers in the medulla, a part of the brain; from there autonomic activity is directed so that the heart rate and resistance of the peripheral blood vessels can be adjusted appropriately to maintain a stable blood pressure.
Baroreflex
A baroreflex is a reflex triggered by the stimulation of a baroreceptor (a collection of sensory nerve endings in the wall of the heart auricles, vena cava, aortic arch and carotid sinuses that are specialized to monitor changes in blood pressure). The baroreflex acts to increase or decrease the blood pressure to maintain a stable blood pressure within the body.
Barotitis media
Barotitis media (or aerotitis media) is inflammation or bleeding in the middle ear caused by difference between the air pressure in the middle ear at of the atmosphere, as occurs in sudden changes in altitude. Symptoms are pain, tinnitus, diminished hearing, and vertigo.
Baseline
A baseline is a measurement that serves as a basis to which all following measurements are compared. An example: before exercise, your heart rate is measured. During exercise, your increased heart rate is measured and compared to your resting baseline measurement taken before exercise started.
Basophil
Basophils are white blood cells that stain readily with basic dyes. Their nucleus is surrounded by granular cytoplasm. Basophils are produced continually by stem cells in the bone marrow. The function of basophils is not fully understood, but it is known that they are capable of ingesting foreign particles and produce heparin and histamine (chemicals which induce inflammation).
BAT
Battery
Batch crystallization
Batch crystallization is a technique used for growing protein crystals by adding a precipitating solution directly to a protein solution and mixing them together. Once the precipitating solution is added, the mother liquor becomes supersaturated causing the proteins to solidify and crystallize.
BATSW
Battery Switch
BAUD
A Data Transfer rate of one signaling unit per second
BBN
Bolt Beranek and Newman, Inc.
BCD
Baseline Configuration Document
Bed rest
Bed rest studies are tests performed where the subject is confined to bed to simulate stays in space by reducing gravitational pull to the antigravity muscles and bones.
Behavior and performance
Behavior and performance research conducted by NASA is designed to develop a knowledge of how space mission design and events, and spacecraft environment, affect the behavior and performance of crews. Countermeasures developed from this research will enhance the ability of humans in space and on the ground to cope with issues such as team problem-solving, decision-making and communication, team structure and expertise, cultural variability, uncertainty, stressors like isolation and confinement, and time pressure.
Benzene
Benzene is a highly toxic hydrocarbon used as the basic structure in the aromatic compounds of all chemistry and as a sorbent.
Benzoic acid
Benzoic acid is an organic aromatic acid commonly used as a preservative to inhibit the growth of bacteria and sometimes used as an antifungal agent.
BEST
Bioexperiment Support and Transfer
Beta globulin
Globulins are a group of global proteins that are generally insoluble in water and present in blood, eggs, milk, and as a reserve protein in seeds. Blood serum globulins comprise four types: alpha-1, alpha-2, beta-globulins which serve as carrier proteins, and gamma-globulins which include the immunoglobulins responsible for immune responses.
Beta ray
A beta ray is a stream of high speed electrons, or beta particles, emitted from a radioactive nucleus in beta decay.
Beta-cloth
Beta-cloth is a glass fiber material characterized by extremely small diameter fibers, which provides a non-flammable, high temperature flame barrier.
Beta-hemolytic
Beta-hemolytic refers to complete or true hemolysis, observed in blood agar cultures of various bacteria, especially hemolytic streptococci; virtually all of the erythrocytes are destroyed in a wide circular zone around the colony, thereby resulting in a clear “halo” of transparent agar; the zone of hemolysis is frequently much wider than the diameter of the colony.
BGE
Biological Growth Experiment
Biceps femoris
The biceps femoris is a muscle of the posterior thigh, which acts to flex the knee and rotate the tibia laterally.
Bifurcation
A bifurcation is a forking or division into two branches.
Bigeminy
Bigeminy is a condition in which alternate ectopic beats of the heart are felt as a double pulse beat.
Bilateral
Bilateral means appearing or occurring on two sides.
Bilirubin
Bilirubin is one bile pigment (the other is named biliverdin), which is produced by the breakdown of the blood pigment hemoglobin. Bilirubin has a yellow-orange color. Bile itself is a greenish-yellow alkaline fluid produced by the liver and stored in the gall-bladder. It assists the digestion and absorption of fats.
Binary
Binary describes something made of two things or two parts. In chemistry, this might mean a substance made of two elements or two compounds.
Binding
Binding refers to the combining or uniting of molecules by employing reactive groups within the molecule or by using a binding chemical. Binding is especially associated with a chemical bond that is easily broken.
Bioassay
Bioassay is a technique used to determine the potency or concentration of a substance (such as a drug) by comparing its effect on a test organism with that of a standard preparation.
Bioavailability
Bioavailability is the degree to which an agent, such as a drug or nutrient, becomes available at the site of activity in the body.
Biochemical
Biochemical refers to the chemical reactions that occur within a living organism, such as the breakdown or manufacture of biological molecules by enzymes.
Biochemistry
Biochemistry is the study of the chemistry of living organisms, especially the structure and function of their chemical components (principally proteins, carbohydrates, lipids, and nucleic acids).
Biocompatibility
Biocompatibility is the ability of biologic materials to exist or perform in harmonious combination.
Biofeedback
Biofeedback is a training technique that enables an individual to gain some element of voluntary control over autonomic (involuntary) body functions, such as heart rate. This is accomplished by providing immediate information about these bodily functions to the individual. Biofeedback is currently used as an experimental treatment for disturbances of bodily regulation, such as hypertension, and is most effective in the treatment of high blood pressure, migraines, and epilepsy.
Bioinstrumentation
Bioinstrumentation is the use of a sensor or other device (bioinstrument) to record and transmit physiologic data to a receiving and monitoring station. The device is attached to or embedded in the subject’s body.
Biologically active
A biologically active molecule has a unique structure that allows it to participate in biochemical reactions.
Biomass
Biomass is the total mass of all the organisms of a given type and/or in a given area. It is normally measured in terms of grams of dry mass per square meter.
Biomechanics
Biomechanics is the application of the principles of mechanics to living systems, particularly those living systems that have coordinated movements.
Biopsy
Biopsy is the process of removing a small section of tissue from a potentially diseased organ or tissue in a living organism. The biopsy sample can undergo more detailed diagnostic examinations, such as microscopic analysis.
Biorack
Biorack is the name for a multipurpose facility designed by the European Space Agency (ESA) to study the effects of microgravity and cosmic radiation on small life forms such as cells, tissue samples, small organisms and plants. Biorack contains three incubators, which operate at different temperatures, a cooler, a freezer and two 1-G reference centrifuges.
Bioreactor
Bioregeneration
Bioregeneration is the renewing or restoring of life-supporting resources using biological processes; usually describing processes in a closed system.
Bioregenerative
Bioregenerative systems renew or restore life-supporting resources using biological processes.
Biorespirator
A biorespirator is a device worn over the nose and mouth that limits the inhalation of toxic materials or the contamination of one's surroundings. They range from disposable dust masks to self-contained breathing apparatus.
Biorhythms
Biorhythms are roughly periodic changes in the behavior or physiology of an organism that is maintained and generated by a biological clock. Well known examples are the sleep cycle, annual rhythms, or menstrual cycles.
Biosensor
A biosensor is a device that translates biological variables such as electric potentials, movement and chemical concentrations into electrical signals.
Biosphere
The biosphere is the whole region of the Earth's surface, including the sea and the air, that is inhabited by living organisms.
Biostack
The Biostack is made up of cylindrical containers with layers of dormant biological objects, such as seeds, interleaved with sheets of light or radiation particle detectors. The biological objects identify the biological damage of light or radiation, while the detector sheets map the location of the hit and the size of light particles.
Biotechnology
Biotechnology refers to the industry that uses biological processes to make a product, such as a drug. An example is the use of yeast in the fermentation of beer.
BIT
Built-in Test
BIT
Least possible quantity of information in a digital system
BITE
Built-in Test Equipment
Blastoid
A blastoid is a cell that has undergone blastogenesis which is the transformation of a functionally dormant cell to an active cell. A blastoid cell is characterized by expansion of the cytoplasm and enlargement of the cell nucleus.
Blood pressure
Blood pressure is the force exerted by blood on the walls of the arteries. This pressure is greatest during the contraction of the ventricles of the heart (systolic pressure), which forces blood into the arterial system. Pressure falls to its lowest level when the heart is filling with blood (diastolic pressure).
Blood Urea Nitrogen (BUN)
Blood Urea Nitrogen (BUN) is nitrogen in the blood in the form of urea. The urea is formed in the liver as the end product of protein metabolism and is deposited in the blood to be excreted through the kidneys. The BUN, determined by blood test, is directly related to the metabolic function of the liver and the excretory function of the kidney.
Blood volume
Blood volume is the total amount of circulating blood in the body, normally about 5.5 liters.
BMCP
Biomedical Computer Programs, UCLA
BMMD
Body Mass Measurement Device
BMRP
Biomedical Research Project
BN
Ballistic Number
Body axis
The body axis is an imaginary longitudinal line through the vertical center of the body (head to feet) or one of its parts, or a line about which the body or a part rotates. Development of the body in vertebrates and most other animals occurs in a nearly symmetrical fashion around the body axis.
BOL
Beginning of Life
Bomb calorimetry
Bomb calorimetry is a method used to determine the potential energy of organic substances, including those in foods by means of an instrument called a bomb calorimeter. The bomb calorimeter consists of a hollow steel container, lined with platinum and filled with pure oxygen, into which a weighed quantity of food is placed and ignited with an electric fuse. The heat produced is absorbed by water surrounding the bomb and, from the rise in temperature, the calories liberated are calculated.
Bone and calcium physiology
Bone physiology, or bone and calcium physiology as it's also known, is the study of the structure, processes and function of bone and its major constituent, calcium.
Bone demineralization
Bone demineralization is the loss of minerals, including calcium and phosphorous, from the bone.
Bone density
Bone density is the mass per unit volume of bone under specified conditions of pressure and temperature.
Bone formation
Bone formation is the process by which new bone is created from cells known as osteoblasts or bone forming cells. Bone formation adds minerals such as calcium to bone matrix, making it stronger.
Bone loss
Bone loss is the weakening and destruction of bone, particularly through demineralization. Demineralization is the loss of minerals, such as calcium from the bones or other mineralized structures of the body.
Bone marrow
Bone marrow is the soft tissue contained within the internal cavities of the bones. Bone marrow is a site of blood cell formation, especially in young animals and humans.
Bone matrix
Bone comprises a matrix of collagen fibers (30%) impregnated with bone salts (70%), mostly calcium phosphate and carbonate.
Bone metabolism
Bone metabolism describes the process by which bone is destroyed and rebuilt at any given time to keep up its strength.
Bone mineral mass
Bone mineral mass is the amount of mineral in a bone.
Bone mineralization
Bone mineralization is the process of adding minerals such as calcium and phosphorous to the bone.
Bone mineralization rate
Bone mineralization rate is the speed at which minerals such as calcium and phosphorous are added to the bone.
Bone physiology
Bone physiology, or bone and calcium physiology as it's also known, is the study of the structure, processes and function of bone and its major constituent, calcium.
Bone remodeling site
Bone remodeling sites are specific sites located along most of the outer surface of bone where the synthesis and resorption of bone takes place. The sites are regulated by specialized cells which control the synthesis or resorption process. Long bones also have remodeling sites along the inner surface of the bone shaft, adjacent to the bone marrow cavity.
Bone resorption
Bone resorption is the absorption of the bone by large multi-nucleated cells called osteoclasts; resorption occurs normally in very small amounts, but can claim large quantities of bone in circumstances where normal physical weight-bearing stress is absent, such as bed rest or exposure to microgravity. The loss of calcium is associated with resorption of bone.
BOP
Baseline Operation Plan
Boric acid
Boric Acid is a white, odorless powder or crystalline substance used as a buffer.
Boyden chamber
A Boyden chamber is a simple chamber used to test for chemotaxis, especially of leukocytes. Consists of two compartments separated by a millipore filter (3 - 8 micrometer pore size); chemotactic factor is placed in one compartment and the gradient develops across the thickness of the filter (ca 150 micrometer). Cell movement into the filter is measured after an incubation period less than the time taken for the gradient to decay. See also checkerboard assay.
The brachialis is a muscle that is situated at the front of the upper arm and contracts to flex (lift-up) the forearm; it works against the triceps brachii (lowering the forearm).
Bradycardia
Bradycardia is relatively slow heart action, usually at a rate of less than 60 beats per minute.
Bremsstrahlung
Gamma particles are produced in abundance when high-energy electrons impinge on any material. The electrons are subject to violent collisions, and the photons that result from these collisions are formally called bremsstrahlung radiation, (bremsstrahlung is German for decelerated-radiation). A gamma particle is known by other names, such as X-ray, photons and light. Low-energy forms are called ultraviolet rays, infrared rays, even radio waves. A photon is one of the fundamental particles in nature and it plays an important role in being involved in the interactions between electrons. Photons are the most familiar particles in everyday existence. The light we see, the radiant heat we feel, microwaves to cook with, are all photons of different energies. A gamma is simply a name given to the most energetic of these particles.
BRFS
Biotelemetry System Radio Frequency Simulator
Brittle
Brittle means easily broken, cracked or snapped.
Bronchitis
Bronchitis is an acute or chronic inflammation of mucous membranes of the tracheobronchial tree.
Bronchoalveolar lavage
Bronchoalveolar lavage (BAL) is a procedure that uses the bronchoscope to send water (sterile saline solution) into the bronchioles and air sacs. The bronchoscope then sucks the water back out. Doctors can examine cells and mucus removed this way to diagnose diseases. Sometimes BAL is used to clear extra mucus or other secretions from the lungs.
BRP
Biological Research Project
BRS
Body Restraint System
BSMRC
Biological Specimen Management and Review Committee
BSP
Biospecimen Sharing Program
BTS
Biotelemetry System (a subset or prototype of ABS for SL-3)
BTU
British Thermal Unit
Buccal cavity
The buccal cavity is the mouth.
Buffer
A buffer is a system capable of resisting changes in pH, consisting of a conjugate acid-base pair in which the ratio of proton acceptor to proton donor is near unity.
Buffy coat
Buffy coat is the thin yellow-white layer of leukocytes on top of the mass of red cells when whole blood is centrifuged.
Bulk solution
A bulk solution is a solution that contains protein molecules used to form the protein crystals.
Bungee cord
A bungee cord is an elasticized cord.
Buoyancy
Buoyancy is the capacity to float in a liquid medium.
BYTE
Eight Bits
C
Celsius
C
Centrifuge Degrees
C
Continuous Bit Stream
C
Combustible
C&D
Control and Display
C&T
Communications and Tracking
C&W
Caution and Warning
C-peptide
C-peptide, also known as connecting peptide, is a peptide produced (along with insulin) by hydrolysis of the insulin precursor molecule. A certain proportion of the C-peptide is excreted in the urine, and the urinary C-peptide excretion rate is used as a marker for insulin secretion.
C-reactive protein
Serum C-reactive protein concentrations closely follow a person's response to inflammation, theoretically providing a barometer for many disease processes; it is present in acutely ill patients and disappears as the patients recover. C-reactive protein has been detected in bacterial, viral and other infections, as well as in noninfectious diseases. Studies suggest that C-reactive protein activates neutrophils and facilitates cell-mediated cytotoxic reactions against cells infected with microbes and stimulates monocyte-macrophage tumoricidal activity.
C/D
Countdown
C/O
Carry On
C/O
Check Out
CA
Cost Avoidance
CAD
Computer-Aided Design
CADSI
Communications and Data Systems Integration
CAE
Computer-Aided Engineering
Calcified
Calcified refers to the occurrence of the process of calcification, which is the deposition of calcium salts in tissue. This occurs as part of the normal process of bone formation, called ossification.
Calciotropic
Calciotropic refers to the group of hormones responsible for bone growth and remodeling.
Calcitonin
Calcitonin (also called thyrocalcitonin or CT) is a hormone, produced by certain cells in the thyroid gland, that lowers the levels of calcium and phosphate in the blood. Calcitonin is believed to inhibit the resorption of bone.
Calcium (Ca)
Calcium is an element essential for the normal development and functioning of the body, typically present in the blood at a concentration of about 10mg/100ml. Calcium is an important constituent of bones and teeth and is essential for many metabolic processes, including nerve function, muscle contraction and blood clotting.
Calcium alginate
Calcium alginate is a topical hemostatic.
Calcium balance
Calcium balance is a measure of the intake and output of calcium from the body. The amount of free calcium in the body is measured by blood calcium levels. Higher than normal levels of calcium in the blood (hypercalcemia) may be an indication of many things, including an abnormal loss of bone calcium, caused by bone demineralization.
Calcium deposition
Calcium deposition refers to the process by which calcium and phosphate are added to organic bone material (osteoid). The addition of calcium and phosphate is responsible for the final hardening stage during bone formation or remodeling.
Calcium homeostatic mechanism
The calcium homeostatic mechanism refers to a group of physiologic processes which act jointly to maintain normal blood calcium levels by regulating intestinal calcium absorption, calcium deposition and resorption from bone, and calcium excretion.
Calcium lactate
Calcium lactate is a salt of lactic acid commonly used as a calcium replenisher.
Calcium metabolism
Calcium metabolism is the distribution and utilization of calcium throughout the body, such as for bone formation and muscle contraction.
Calcium oxalate
Calcium oxalate is a chemical compound usually found as sediment in the urine and in urinary calculi. It can, if found in large quantities in the urine, indicate a higher than normal loss of calcium from the body, and thus indicate potential disease or abnormalities.
Calcium phosphate
Calcium phosphate is formed when free calcium and phosphate interact. In the human body, this interaction can happen when both minerals are excreted through the urinary tract, due to saturation of both minerals in the body, leading to the build-up of calculi and/or renal stones. Calcium phosphate is also referred to as calcium rock and its chemical formula is Ca3(PO4)2.
Calcium/bone homeostatic system
Calcium/bone homeostatic system is another term for the process of calcium balance, which is a measure of the intake and output of calcium from the body as measured in blood. Higher than normal levels of calcium in the blood (hypercalcemia) may be an indication of many things, including an abnormal loss of bone density. Demineralization is the term used to describe the breakdown of bone minerals, including calcium, during conditions of bed rest or disuse of bones, such as in weightlessness, and in medical conditions like osteoporosis.
Calcium/bone system
Calcium/bone homeostatic system is another term for the process of calcium balance, which is a measure of the intake and output of calcium from the body as measured in blood. Higher than normal levels of calcium in the blood (hypercalcemia) may be an indication of many things, including an abnormal loss of bone density. Demineralization is the term used to describe the breakdown of bone minerals, including calcium, during conditions of bed rest or disuse of bones, such as in weightlessness, and in medical conditions like osteoporosis.
Calculi (plural of calculus)
Calculi are abnormal, hard structures formed in an animal's body. In this database, "calculi" or "calculus" usually refers to urinary calculi, which are calculi formed in the urinary tract. Renal calculi are kidney stones.
CALIB
Calibration
Calibrate
To calibrate means to check or adjust the graduations of a quantitative measuring instrument. To cross-calibrate is to extend the check or adjustment of graduations across one or more instruments.
Calibration curve
A calibration curve is a curve generated to standardize laboratory procedures.
Calisthenics
Calisthenics are gymnastic exercises designed to develop muscle tone and physical well being.
Caloric irrigation
Caloric irrigation is a procedure in which the ears are alternately irrigated with warm or cold water. Warm irrigation produces rotary nystagmus toward the irrigated ear. Cold irrigation produces a rotary nystagmus away from the irrigated ear. If the ear is normal, all irrigations will produce nystagmus that is appoximately equal in intensity.
Caloric nystagmus
Caloric nystagmus is a reflexive rhythmical oscillation (jerky motion) of the eyeballs. The caloric nystagmus effect is stimulated by dropping hot or cold water into the ear.
Caloric test
A caloric test is designed to produce and measure a condition known as caloric nystagmus. Caloric nystagmus is a jerky, involuntary, rapid, rhythmic movement of the eyeball, which may be horizontal, vertical, rotatory or mixed. Caloric nystagmus is induced by injecting warm or cold water into the labyrinth of the inner ear.
Calorie
A calorie is a unit used to denote the energy expenditure of an organism and the fuel or energy value of food.
Calorimetry
Calorimetry is the measurement, usually by use of a calorimeter or other instrument, of heat given off or absorbed.
Calvaria
The calvaria (cranium cerebrale) is the roof of the skull, i.e., the upper dome-like portion of the skull.
CAM
Commercial Aviation and Military
CAM
Computer-Aided Manufacturing
Canadian Space Agency (CSA)
The Canadian Space Agency (CSA) acts as a focal point for Canada’s space activities. The agency encourages and supports research, technology, and operations throughout Canada. CSA is headquartered in Montreal, Quebec, Canada.
Candida albicans
Candida albicans is a species of yeast-like fungi normally a part of human gastrointestinal flora, but can become pathogenic when there is a disturbance in the balance of flora or in debilitation of the host (also called thrush fungus).
Canthus
The outer canthus of the eye refers to the small area of skin closest to the side of the head, where the upper eyelid meets the lower eyelid.
CAP
Crew Activity Plan
CAPCOM
Capsule Communicator
Capillary
A capillary is the narrowest type of blood vessel in the circulatory system. The walls are only one cell layer thick enabling oxygen and nutrients to pass through them into the surrounding tissues. Capillaries also transport waste material, such as urea and carbon dioxide, to venules for excretion.
Capillary density
A high capillary density means that many small capillaries are present in the tissue, allowing a high supply or oxygen and nutrients.
Capillary endothelium
The capillary endothelium is the single layer of cells that build the walls of the capillaries. Capillaries are microscopic blood vessels which enable the exchange of nutrients and wastes between the blood and the tissues.
Capillary tube
A capillary tube is a very thin tube (approximately 1.1 or 0.75 mm in diameter).
Capstan
Capstan is a vertical cleated drum or cylinder, revolving on an upright spindle, and surmounted by a drumhead with sockets for bars or levers. It is much used, especially on shipboard, for moving or raising heavy weights or exerting great power by traction upon a rope or cable, passing around the drum.
Carbohydrate
A carbohydrate is any of various neutral compounds of carbon, hydrogen, and oxygen (as sugars, starches, and celluloses) most of which are formed by green plants and which constitute a major class of animal foods.
Carbon (C)
A nonmetallic tetravalent element (atomic number 6, atomic weight 12.001). Carbon is the major bioelement.
Carbon dioxide (CO2)
Carbon dioxide is a colorless and odorless gas formed in the tissues during metabolism and carried in the blood to the lungs, where it is exhaled (an increase in the concentration of this gas in the blood stimulates respiration). Carbon dioxide occurs in small amounts in the atmosphere (0.04% volume); it is used by plants in the process of photosynthesis. Its chemical symbol is CO2.
Carbon dioxide output
Carbon dioxide output is the full volume of carbon dioxide exhaled.
Carbon monoxide (CO)
Carbon monoxide is a colorless, odorless and poisonous gas formed by the incomplete combustion of carbon (like in car exhaust). Its toxic action is due to its strong ability to bond with red blood cells and thus block the binding site for oxygen, thus reducing the ability for the blood to transport oxygen in the body. Its chemical symbol is CO.
Carbon monoxide diffusing capacity (DLCO)
Carbon monoxide diffusing capacity (DLCO) measures the transfer of a diffusion-limited gas (carbon monoxide, CO) across the alveolocapillary membrane. CO combines with hemoglobin approximately 210 times more readily than oxygen. In the presence of normal amounts of hemoglobin and normal ventilatory function, the primary limiting factor of diffusion of CO is the status of the alveolocapillary membrane. This is significant because DLCO is usually decreased in emphysema because of the decrease in the total lung surface area, loss of capillary bed, increased distance from terminal bronchiole to alveolocapillary membrane and the mismatching of ventilation to blood flow.
Carbon monoxide rebreathing method
Carbon monoxide rebreathing is a safe and reliable method used to determine blood volume. During the procedure, a subject lies in the supine position with a catheter inserted in an antecubital vein. After approximately 20 minutes, a baseline blood sample is collected and analyzed for hematocrit, total hemoglobin, and carboxyhemoglobin. After the baseline blood sample has been collected, the subject breathes pure oxygen in a closed system for approximately one minute. After the one minute, 60 milliliters of carbon monoxide is injected into the rebreathing system and rebreathed for 10 minutes. At the end of the rebreathing period, a second blood sample is drawn.
Carbonaceous
Carbonaceous means producing, containing or pertaining to carbon, a naturally abundant nonmetallic element that occurs in many inorganic and in all organic compounds.
Carcinogen
A carcinogen is any cancer-producing substance.
Carcinoma
A carcinoma is cancerous tissue or cell of epithelial origin.
Cardiac
Cardiac means of, relating to, situated near, or acting on the heart.
Cardiac arrhythmia
A cardiac arrhythmia is any deviation from the normal rhythm of the heart.
Cardiac cycle
The cardiac cycle is the period from the end of one heart contraction to the end of the next.
Cardiac dysrhythmia
Cardiac dysrhythmia is abnormal heart rhythm.
Cardiac filling
Cardiac filling refers to the process by which the heart fills with blood.
Cardiac function
Cardiac function is the hemodynamic and electrophysiological action of the heart, which can be assessed by measuring end diastolic volume, end systolic volume, stroke volume, cardiac output, ejection fraction, and wall thickening.
Cardiac output (CO)
Cardiac output (CO) is the amount of blood pumped by the heart in a unit period of time. The overall blood flow in the circulation of an adult person at rest is about 5000 milliliters per minute.
Cardioacceleration is a term used to describe a condition that increases the heart beat of a living organism.
Cardiogenic Oscillations (CGO)
Cardiogenic Oscillations (CGO) are respiratory oscillations of cardiac origin, i.e., originating from the heart, which are usually apparent on respiratory recordings made by a spirometer (a device which records the movement of air into and out of the lungs).
Cardiologist
A cardiologist is a physician who specializes in the heart and cardiovascular system.
Cardiopulmonary
Cardiopulmonary means of or relating to both the heart and lungs.
Cardiorespiratory
Cardiorespiratory means relating to the heart and lung system.
Cardiotachometer
A cardiotachometer is an instrument that continuously monitors and measures the heart beat.
Cardiothoracic (C/T) ratio
The cardiothoracic (C/T) ratio is the ratio of the transverse diameter of the heart to the internal diameter of the chest at its widest point just above the level of the dome of the diaphragm.
Cardiovascular
Cardiovascular means of or relating to the heart and blood vessels.
Cardiovascular deconditioning
Cardiovascular deconditioning is a decrease in fitness of the cardiovascular system (system of heart and blood vessels that supplies blood throughout the body) and can result from a stay in microgravity. Some deconditioning changes occur within the first few hours of weightlessness, while other changes occur over several days or weeks. In general, changes resulting from adaptation to microgravity include a headward shift of body fluids, consequent loss of water (and lower blood volume) from the body and a slight weakening of the heart muscle due to a decreased work load in space.
Cardiovascular physiology
Cardiovascular physiology is the study of the function of the heart and the blood vessels.
Cardiovascular system
The cardiovascular system is the system of the heart and blood vessels.
Caries
Caries is the molecular decay or death of a bone, in which it becomes softened, discoloured and porous. In dentistry, caries is another name for cavities caused by tooth decay.
Cariogenic
Cariogenic means to produce caries.
Carotid artery
The carotid artery is the main artery that supplies blood to the head. A pair of carotid arteries arise from the aorta and run up the neck; they branch into an external and an internal artery, which supply the head with oxygenated blood.
Carotid sinus
The carotid sinus is a slight dilation of the common carotid artery at its bifurcation into external and internal carotids. The carotid sinus contains baroreceptors, nerve endings specialized to monitor changes in blood pressure.
Cartilage
Cartilage is a dense connective tissue composed of a matrix and is capable of withstanding considerable pressure. Cartilage is commonly found in adults in the nose, ear, intervertebral disks and tendons.
CAS#
Chemical Abstract Standard Number
Casein
Casein is a group of proteins isolated from milk.
Catabolism
Catabolism is the chemical decomposition of complex substances by the body to form simpler ones, accompanied by the release of energy. The substances broken down include nutrients in food (carbohydrates, proteins, etc.), as well as the body's storage products (such as glycogen).
Catalase
Catalase is a hemoprotein that catalyzes the decomposition of hydrogen peroxide to water and oxygen.
Catalyst
A catalyst is substance which increases the rate of a chemical reaction without itself being used up in the reaction.
Cataract
A cataract is an abnormal progressive condition of the lens of the eye, characterized by the loss of transparency. A gray-white opacity can be seen within the lens, behind the pupil.
Catecholamines
Catecholamines are a group of chemical substances, including epinephrine, norepinephrine and dopamine, having various roles (mainly as neurotransmitters) in the functioning of the sympathetic and central nervous systems. Chemically, all contain a benzene ring with adjacent hydroxyl groups and an amine group on a side chain.
Catheter
A catheter is a thin plastic tube that can be inserted into the body to make measurements or add or remove fluid. For example, a catheter can be introduced into an artery and moved to a location in the heart to measure pressure changes.
Cathode
A cathode has a positive electrical charge; all negative ions move towards the cathode.
Cation
A cation is a positively charged ion.
Caudate nucleus
The caudate nucleus is an area of the brain which is a part of several important neural pathways. It helps to control intentional body movements that are normally performed subconsciously, such as the positioning of large body parts (such as the arm) so that other, smaller body parts can be manipulated (such as the fingers and hand).
CB
Control Board
CCA
Contract Change Authorization
CCAFS
Cape Canaveral Air Force Station
CCB
Configuration Control Board
CCBD
Configuration Control Board Directive
CCBO
Configuration Control Board Operations
CCD
Charge Coupled Device
CCF
Control Computing Facility
CCITT
Consultative Committee for International Telephone and Telegraph
CCN
Change Control Notice
CCP
Configuration Change Panel
CCR
Change Control Request
CCS
Central Control Section
CCS
Console Communications System
CCSDS
Consultative Committee for Space Data Systems
CCT
Computer-Compatible Tape
CCTV
Closed Circuit Television
CCW
Counter Clockwise
CCZ
Command and Control Zone
CD
Concept Document
CDC
Count Down Clock
CDM
Communication Data Manager
CDMS
Command and Data Management Subsystem
CDMS
Command and Data Management System
CDR
Critical Design Review
CDSC
Communications Distribution and Switching Center
CDT
Configuration Data Table
CDTR
Cassette Data Tape Recorder
CE
Change Evaluation
CE&IS
Combined Elements and Integrated Systems
Cecum
The cecum is the beginning of the large intestine, a blind pouch into which the ileum (the last part of the small intestine) opens.
CEDC
Cyclic-Error Detection Code
CEI
Configuration End Item
CEI
Contract End Item
Cell
A cell is the basic structural and functional unit of all organisms; the smallest structure capable of performing all the activities vital to life.
Cell and molecular biology
Researchers in gravitational cell and molecular biology study the effects of gravity and its absence on biological processes at the cellular, organelle, and molecular levels.
Cell biology
Cell biology is the study of cellular form and function on a microscopic and molecular level.
Cell culture
Cell culture is the maintenance or growth of cells after removal from the body, commonly on a glass surface immersed in nutrient fluid.
Cell differentiation
Cell differentiation, in embryology, is the process in embryonic development during which unspecialized cells become specialized for particular functions. Differentiation, in oncology, is the degree of similarity or difference of tumor cells to the structure of the organ from which the tumor arose.
Cell-mediated immunity
Cell-mediated immunity is that component of immunity in which specially sensitized lymphocytes (T-cells) attach to antigens to destroy them.
Cellular
Cellular means of, relating to, or consisting of cells.
Cellulolytic
Cellulolytic means having the capacity to hydrolyze cellulose.
Cellulose
Cellulose is a polysaccharide carbohydrate composed of linked glucose units. It is the main consitutent of plant cell walls and is the most common organic compound on Earth.
Cellulose acetate electrophoresis
Cellulose acetate electrophoresis is a process by which charged particles are separated in a gel by differences in their charge density. The particles are then detected by staining on a cellulose acetate sheet for quantification of particle size.
CELSS
Controlled Environment Life Support System
Center of mass
The center of mass of a body is the three-dimensional midpoint of its mass, the point at which the mass can be considered to be concentrated.
Central Nervous System (CNS)
The Central Nervous System (CNS) consists of the brain and spinal cord. The CNS is responsible for the integration of all nervous activities.
Central Venous Pressure (CVP)
Central venous pressure (CVP) is the pressure in the right atrium of the heart (normally 0 mmHg). CVP is regulated by the ability of the heart to pump blood out of the right atrium and the tendency for blood to flow from the peripheral vessels back into the heart.
Centrifugal
Centrifugal means acting by centrifugal force, the force produced by rotation about a central point, which causes rotated objects or parts of them to move outward, away from the center.
Centrifuge
A centrifuge is a device that rotates at various speeds about a fixed, central point; it can separate liquids from solids or liquids of different densities by way of the centrifugal force resulting from its rotation.
Centripetal acceleration
Centripetal acceleration occurs during uniform circular motion. It is the average acceleration, proportional to the change in velocity, directed towards the center of the circle. Centripetal force, which causes centripetal acceleration, acts on the body in motion and is directed towards the center of the circle.
Centromere banding (C-banding)
Centromere banding (C-banding) is a selective chromosome banding used in human cytogenetics, employing Giemsa after most of the DNA is denatured.
CER
Cost Estimating Relationship
Cerebellar
Cerebellar refers to cerebellum, the largest part of the hindbrain. The cerebellum is concerned with coordination of muscle movements and is essential for maintenance of muscle tone and balance.
Cerebellum
The cerebellum is the largest part of the hindbrain and is located behind the pons and the medulla oblongata. The cerebellum is concerned with coordination of muscle movements. It is also essential for maintenance of muscle tone, balance, and the synchronization of activity in groups of muscles under voluntary control, converting muscular contractions into smooth coordinated movements.
Cerebral
The term cerebral refers to the portion of the brain that comprises mainly the central hemisphere (cerebral cortex and basal ganglia).
Cerebral blood flow
Cerebral blood flow is the amount of blood flowing through the cerebrum (the brain).
Cerebral cortex
The cerebral cortex is the surface layer of gray matter of the cerebrum that functions chiefly in coordination of sensory and motor information.
Cerenkov radiation
Cerenkov radiation is visible light produced by charged particles (as electrons) traversing a transparent medium at a speed greater than that of light in the same medium; it is also called Cerenkov light. The light observed is frequently attributed to a shock wave phenomenon and has been thought of as an optical analog of the sonic boom. High-energy nuclei with a charge greater than or equal to 6 are capable of producing Cerenkov light.
CERMA
Centre de Recherches de Medicine Aeronautique
Ceruloplasmin
Ceruloplasmin is a copper-containing alpha globulin of blood plasma. It is believed to play a part in red blood cell production and oxygen (O2) reduction.
Cervical
Cervical means of or relating to the neck or cervix of the womb.
Cervical vertebrae
Cervical vertebrae are the seven bones making up the neck region of the backbone.
CEVP
Countermeasure Evaluation Validation Project
CF
Cryogenic Freezer
CFA
Centrifugal Fast Analyzer
CFE
Contractor Furnished Equipment
CFM
Cubic Feet per Minute
CFR
Code of Federal Regulations
CG
Center of Gravity
Challenger
Challenger is the name of the second the American Space Shuttle built. Challenger’s maiden voyage was STS-6 in April 1983. Challenger traveled nine times into space before the orbiter was destroyed in an accident on January 28, 1986, during the launch of the STS-51L mission.
CHAN
Channel
CHARA
Characteristics
Chelicerae
Chelicerae are one of the anterior parts of appendages of an arachnid, often specialized as fangs.
Chemical oxygen demand
Chemical oxygen demand is the amount of oxygen required to oxidize the inorganic and organic matter in water.
Chemiluminescence
Chemiluminescense is light produced by chemical reaction usually at, or below, room temperature.
Chemoreceptive
Chemoreceptive means pertaining to chemoreception, the physiological detection of chemical stimuli. For example, the chemoreceptors in the carotid and aortic bodies are stimulated by chemical changes, such as hypoxia, in the composition of the blood.
Chemotactic
Chemotactic means relating to the attraction of living protoplasm to chemical stimuli whereby the cells are attracted or repelled by acids, alkalies or other bodies exhibiting chemical properties.
Chemotaxis
Chemotaxis is a response of motile cells or organisms in which the direction of movement is affected by the gradient of a diffusible substance. Differs from chemokinesis in that the gradient alters probability of motion in one direction only, rather than rate or frequency of random motion.
CHG
Change
CHIT
Crew Honest Input to Training
Chloride (Cl2)
Chloride is a chemical compound containing chlorine. Chloride is the major extracellular ion and is significantly involved in the maintenance of proper water distribution, osmotic pressure and normal anion-cation balance in the extracellular fluid compartment.
Chloroform
Chloroform is a nonflammable, volatile liquid that was the first inhalation anesthetic to be discovered. It is a dangerous drug which can cause hypotension, myocardial and respiratory depression, cardiogenic shock, ventricular fibrillation, coma, and death if improper dosage is used. Delayed poisoning, even weeks after apparently complete recovery, can occur and serious vision or eye damage is frequently reported.
Chloroplast
A chloroplast is a cellular organelle that contains chlorophyll and is the site of photosynthesis and starch formation in plant cells.
Chocolate agar
Chocolate agar is agar to which blood has been added and heated until the blood becomes brown or chocolate in color.
Cholesterol
Cholesterol is a fat-soluble crystalline steroid alcohol found in animal fats and oils, and egg yolks and widely distributed through the body, especially in the bile, blood, brain tissue, liver, kidneys adrenal glands, and myelin sheaths of nerve fiber. It facilitates the absorption and transport of fatty acids and acts as the precursor of the synthesis of vitamin D at the surface of the skin, as well as for the synthesis of the various steroid hormones, including cortisol, cortisone, and aldosterone in the adrenal glands and of the sex hormones progesterone, estrogen, and testosterone.
Cholinergic
Cholinergic means secreting or stimulated by the neurotransmitter acetylcholine, or producing the effects of acetylcholine.
Chondritic
Chondritic means characterized by the presence of chondrules (rounded granules of cosmic origin often found embedded in meteoric stones and sometimes free in marine sediments).
Chondrocyte
A chondrocyte is a mature cartilage cell.
Chorioallantoic membrane
The chorioallantoic membrane is the extra-embryonic membrane formed by the fusion of the allantois with the serosa or false chorion. In mammals, it forms the fetal portion of the placenta; in avian embryos, it is fused with the shell.
Choroid plexus
The choroid plexus is a rich network of blood vessels located in the brain, and is responsible for the production of cerebrospinal fluid, the fluid which surrounds and cushions the brain and spinal cord.
Chromium
Chromium is a metallic, non-toxic element, with period table symbol Cr. Chromium does not have any function in the human body.
Chromium-51 (Cr51)
Chromium-51 (Cr51) is an ion of the element chromium, which is used as a radioactive tracer because it binds to red blood cells. By measuring the amount of radioactivity produced by the Cr51, red blood cell mass and survival can be measured.
Chromosomal
Chromosomal refers to chromosomes. Chromosomes contain DNA, which transmits genetic information. They are located in the nucleus of both plant and animal cells. In humans there are 46 chromosomes.
Chromosome
A chromosome is a body located within the cell nucleus of both plant and animal cells (normally 46 in humans). Each chromosome is composed of deoxyribonucleic acid (DNA) and specialized protein molecules, which convey genetic information.
Chromosome aberration
Chromosome aberration is any deviation from the normal number or morphology of chromosomes.
Chromotrophic acid
Chromotrophic (or chromotrophic) acid is used as a reagent in analytical methods and in chromotropes, which are dyes that have the property of changing from red to blue after treating a tissue specimen.
Chronic pulse/action relation
Chronic pulse/action relation means that for any contraction of a muscle, an electrical pulse, from a source such as the brain, must be generated. A specific delay between pulse generation and muscle action depends on various factors such as age, overall health, condition, mood, etc.
Chronobiology
Chronobiology is the aspect of biology concerned with the timing of biological events, especially repetitive or cyclic phenomena in individual organisms.
Chronotropic
Chronotropic means affecting the time or rate, as the rate of contraction of the heart.
CHX
Cabin Heat Exchanger
CI
Configuration Inspection
CID
Cargo Integration Document
CID
Cable Interconnect Diagram
CIL
Critical Items List
CIM
Computer Input Multiplexer
CIN
Configuration Identification Number
CIO
Customer Integration Office
CIR
Cargo Integration Review
Circadian
Circadian means being, having, characterized by, or occurring in approximately 24-hour periods or cycles.
Circadian phase
All biological rhythms, including circadian rhythms, fluctuate between high and low values during a specified interval of time. The largest values are called "peaks", while the corresponding lowest values are called "troughs." The term "circadian phase" describes the time location during a 360 degree cycle, usually the peak or trough of the cycle with reference to some external point, such as local time, or the beginning of sleep.
Circadian rhythm
A circadian rhythm is a biological rhythm that repeats with a cycle of about 24 hours.
Circulation
Circulation refers to the cardiovascular system of the body in which the heart, together with two networks of blood vessels (arteries and veins), facilitates the movement of blood throughout the body. Circulation transports nutrients and oxygen to the tissues and removes waste products from the body.
Circulatory system
The circulatory system delivers oxygen and nutrients throughout the body by a complex network of vessels -- arteries, arterioles, capillaries and veins. Arteries, arterioles and the microscopic capillaries carry blood to all parts of the body and allow exchange of nutrients and wastes through capillary walls from blood to the tissues and organs. Veins carry deoxygenated blood back to the lungs for reoxygenation.
CIS
Central Integration Site
Cislunar
Cislunar refers to that region of space between the Earth and the Moon (or the Moon's orbit).
CITE
Cargo Integration Test Equipment
Citrate
A citrate is a compound of citric acid and a base.
CL
Corrosive Liquid
CLA
Current Limiter Assembly
Class I
PAM-D Class Satellite
Class II
PAM-A Class Satellite
Class III
IUS Class Satellite
Class IV
Centaur Class Satellite
Clearance
Clearance is the removal of a substance from the blood via the kidneys. Kidney function can be tested by measuring the amount of a specific substance excreted in the urine in a given length of time.
Clinical medicine
Clinical medicine is the branch of medicine dealing with the study of actual patients and the diagnosis and treatment of disease at the bedside, as opposed to the study of disease by pathologic examination or research in basic sciences.
Clinostat
A clinostat is a device which uses a motor to rotate a wheel on which a sample under investigation (such as a plant in a pot) is attached. In the example of an attached plant, as the plant rotates, both the stem and roots will grow horizontally instead of exhibiting characteristic geotropic (gravity-oriented) responses.
CLS
Contingency Landing Site
cm
Centimeter
CM
Channel Electron Multiplier
CM
Command Module
CM
Controlled Material
CMB
Configuration Management Board
CMBD
Configuration Management Board Directive
CMC
Command Module Computer
CMC
Configuration Management Control
CMD
Command
CMG
Control Moment Gyro
CMO
Configuration Management Office
CMP
Configuration Management Plan
CMRR
Computer Materials Request Request
CMS
Configuration Management System
CNES
Centre Natianal D’Etudes Spatiales (French Space Agency). CNES is headquartered in Paris, France.
CO
Communications Officer
CO
Contracting Officer
Co-I
Co-Investigator
COAS
Course Optical Alignment Sight
COAX
Coaxial, Coaxial Cable
Cobalt
Cobalt is a tough lustrous silver-white magnetic metallic element that is related to and occurs with iron and nickel and is used especially in alloys.
COC
Certificate of Compliance
Cocci
Cocci are bacteria of round, spheroidal or ovoid form.
Coccus (plural cocci)
Coccus (plural cocci) refers to a bacterium with a rounded or spherical shape.
Codocyte
A codocyte is a red blood cell characterized by a bell-shaped appearance.
CofF
Construction of Facility
COFR
Certification of Flight Readiness
Cognitive
Cognitive means pertaining to the mental processes by which knowledge is acquired and used, including awareness, comprehension, judgment, memory and reasoning.
Cohesion
Cohesion is the ability to stick together.
COL
Carry-on-Lab
Colcemid
Colcemid is a compound that is used to stop cell division at the stage of metaphase.
Cold pressor test
The cold pressor test is a test measuring the tendency to develop essential hypertension. One hand is placed in ice water. An excessive rise in the blood pressure or an unusual delay in the return of normal blood pressure when the hand is removed from the water is believed to indicate that the individual is at risk for hypertension.
Collagen
Collagen is a protein that is the principal constituent of white fibrous connective tissue found in tendons, skin, bone, cartilage and ligaments; it is relatively inelastic (not flexible), but has a high tensile strength (ability to resist stretching).
Collagenous
Collagenous describes something composed of collagen. Collagen is a protein that is the principal constituent of white fibrous connective tissue. Collagen is found in skin, bone, cartilage, and ligaments. It is relatively inelastic (not flexible) but has a high tensile strength (able to resist forces of stretching).
Collimate
Collimate means to make straight. Collimation is the process, in X-ray, of restricting and confining the X-ray beam to a given area and, in nuclear medicine, of restricting the detection of emitted radiation from a given area of interest.
Collision
A collision is an encounter between two or more particles, photons, atoms or nuclei during which quantities of energy, momentum, and charge may be exchanged. The products of the collision may or may not be the same as the pre-collision particles. The collision may be actual contact or the close approach and deflection of the particles.
Colloidal
Colloidal describes atoms or molecules dispersed in a gas, liquid or solid, which resist sedimentation (setting to the bottom), diffusion (spreading out), and filtration.
Colony
A colony is a group of the same kind of animals, plants, or one-celled organism living or growing together.
Colony Forming Unit (CFU)
A Colony Forming Unit (CFU) is a colony that has grown on a filter that originated from one microorganism in the water sample.
Columbia
NASA operates four space shuttle vehicles, also called orbiters. Each one is named after famous historic sailing ships. Columbia is the oldest orbiter; its maiden voyage was also the first flight of a Space Shuttle, STS-1 in April 1981.
COM
Configuration Management
Combustion
Combustion is the burning of a material, i.e., a chemical change accompanied by the production of heat and light.
Commode
A commode is another term for a toilet.
COMPA
Compatibility
Compact bone
Compact bone tissue forms the external layer of all bones in the body. It is very dense bone with few open spaces and is found mainly in the long bones (i.e., those that absorb the weight of the body). Compact bone tissue provides protection and support and helps the long bones resist the stress of weight placed on them.
Complement
Complement refers to a group of about 20 serum proteins with the overall function of controlling inflammation. Complement proteins act to (1) assist white blood cells in phagocytosis, (2) attract white blood cells to sites of infection, (3) increase blood flow to the site of activation and increase permeability of capillaries to plasma molecules and, (4) damage to plasma membranes of bacteria cells, viruses or organisms by lysis of the cell.
Complement-fixing antibody
A complement-fixing antibody is a sensitizing substance; an antibody that combines with and sensitizes an antigen, leading to the activation of complement, sometimes, but not always resulting in lysis.
Complete blood count (CBC)
Complete blood count (CBC) is a determination of the number of red and white blood cells per cubic centimeter (1 milliliter) of blood.
Compliance (vascular)
Vascular compliance is the ability of blood vessels to become larger in diameter, or distend, to accommodate blood flow. It is calculated by dividing the volume change of a vessel by the pressure change produced by blood flow.
Compound
A compound is a pure and homogeneous substance consisting of atoms or ions of different elements in definite proportions, usually having properties unlike those of its constituent elements. A compound can be broken down into two or more other substances by chemical means.
COMSAT
Communications Satellite
Concanavalin A (ConA)
Concanavalin A is a chemical compound extracted from the jack bean. This compound agglutinates (clumps or sticks red blood cells together) the blood of mammals. It stimulates T-lymphocytes more vigorously than B-lymphocytes.
Concentric
A concentric contraction causes muscle movement that shortens the muscle.
Concomitant
Concomitant means designating one or more things, occurring simultaneously, that may or may not be interrelated.
Condensate
Condensate is the liquid formed from a vapor (gas) or a solid formed from a liquid through a chemical phase change. For instance, water condensate forms on the can of a cold soda as it sits at room temperature in a humid environment.
Conductivity
Conductivity is a measure of the ability of a material to conduct electrical charge.
Conductometrics
Conductometrics is determination of the amount of something in a solution by measuring the electrical conductivity of the solution.
Confluence
Confluence is the flowing together of two streams.
Conifer
Conifers (Latin, coniferophyta) are seed-bearing plants such as pine, fir, and spruce trees. Conifers are typically evergreen trees that inhabit cool temperate regions and have leaves in the form of needles or scales. The wood of conifers, which is called “softwood” in contrast to the hardwood of angiosperm trees, is widely used for timber and pulp.
Conjunctivitis
Conjunctivitis is the inflammation of the mucous membrane covering the anterior surface of the eyeball and lining of the eyelids.
CONN
Connector
Connective tissue
Connective tissue supports, binds, or separates more specialized tissues and organs of the body; "packing tissue" of the body. Types of connective tissue include bone, cartilage, tendon, ligament, adipose (fat), areolar and elastic.
Constituent
Constituent is a part of the whole; a component.
Consumables
Consumables are items that are meant to be used up, e.g. food.
Contact angle
A contact angle is the angle between the solid surface (plate or vessel) and the liquid surface.
Contaminants
Contaminants are substances that make another substance impure or corrupt by contact or mixture.
Contractile
Contractile means being capable of contracting or producing contraction (becoming shorter in length or size).
Contractile properties
Contractile properties are the abilities to shorten or to undergo a reduction in size; in the case of muscle, contraction means the muscle either shortens or increases in tension.
Contralateral
Contralateral means pertaining to the opposite side.
Control
A control is a test subject not exposed to the treatment or condition being studied by the experiment. Controls are used to isolate factors or conditions which vary in other subjects under experimentation.
Control system
A control system is one that provides operation, regulation, or guidance a machine or vehicle.
Control unit
The control unit of the Svet greenhouse provides automatic measurement of Svet environmental parameters every 4 hours.
Controlled frequency breathing
Controlled frequency breathing is a test where a subject is asked to adjust his breathing rate in time with a recording of normal, rapid and slow breathing rates.
Convection
Convection is the transfer of heat by the circulation or movement of heated parts in a liquid or gas. Convection is also the circulatory motion that occurs in a fluid which is at a nonuniform (or varying) temperature caused by the variation of the density of liquid at different temperatures and the action of gravity.
Coolanol
Coolanol is a ready-to-use 50/50 blend of premium quality anti-freeze and deionized water.
COP
Co-orbiting Platform
Copper
Copper is a malleable reddish-brown metallic element. It is a component of several important enzymes in the body and is important for red blood cell and bone formation.
CORE
Common Operational Research Equipment
Cornmealt-malt-yeast agar
Cornmealt-malt-yeast agar is a culture medium that is low in nutrients, used to study yeastlike and filamentous fungi; it suppresses vegetative growth, while stimulating sporulation of many species. It is widely used to produce the distinctive and rapidly diagnostic chlymydiospores of Candida albicans.
Correlate
Correlate means to show a relationship between entities.
Cortex
The cortex of an organ refers to the outer portion (layer) of the organ.
Corticosteroid
A corticosteroid is a steroid (a type of hormone) produced by the adrenal cortex of the adrenal glands. Corticosteroids all have similar chemical formulas, but serve a wide variety of functions in the body, including fluid and mineral regulation, metabolism, reproductive development, growth, the regulation of body temperature and the absorption of nutrients from the intestines.
Cortisol
Cortisol (hydrocortisone) is a steroid hormone synthesized and released by the cortex of the adrenal glands; it is important for normal carbohydrate metabolism and response to stress.
Corynebacteria
Corynebacteria are members of the family Corynebacteriaceae or the genus Corynebacterium, a group of nonmotile, aerobic to anaerobic bacteria. They stain irregularly and are club-shaped, being straight to slightly curved. These organisms are widely distributed in nature, and some are pathogenic.
COSMIC
Coherent Optical System of Modular Imaging Collectors
Cosmic rays
Cosmic rays are charged particles (ions) that originate outside the solar system. They move at high velocity and penetrate the earth's atmosphere at speeds approaching that of light.
Cosmos Biosatellite
The Cosmos Biosatellite Program consists of a group of Russian unmanned satellites which carry biological specimens, including rats and monkeys, into space to examine how space flight effects living systems.
Costodiaphragmatic
Costodiaphragmatic
Coulter counter
A Coulter counter is a particle counter used for bacteria or eukaryotic cells; it works by detecting change in electrical conductance of a small aperture as fluid containing cells is drawn through.
Countermeasure
A countermeasure is a measure or action taken in opposition to another. Several countermeasures are used to counteract the negative effects of space flight, including the performance of rigorous exercise to reduce the degeneration of muscles and bones caused by disuse during stays in microgravity.
Coxsackie virus
Coxsackie virus is a picornavirus (included in the genus Enterovirus) of spherical shape that is about 28 nanometers in diameter. Picornoviruses cause a variety of diseases in man.
CP
Control Panel
CPCB
Crew Procedures Change Board
CPCR
Crew Procedures Change Request
CPES
Crew Procedures Evaluation Simulator
CPM
Counts per Minute
CPS
Course Pointing System
CPSE
Common Payload Support Equipment
CPU
Computer Processing Unit
CPU
Central Processing Unit
CR
Change Request
CR
Conference Room
Cratylia mollis
Cratylia mollis is a type of shrub found in South America.
CRC
Cyclic Redundancy Check
Creatine
Creatine is a precursor of phosphocreatine which is an important energy reservoir in skeletal muscle. Phosphocreatine transfers its phosphate and energy to ADP to create ATP.
Creatine kinase
Creatine kinase is an enzyme present in skeletal and cardiac muscle and in the brain. Very high levels in the blood can indicate the presence of disease or an abnormality.
Creatine phosphokinase (CPK)
Creatine phosphokinase (CPK), also called creatine kinase, is an enzyme in muscle, brain and other tissues that catalyzes the transfer of a phosphate group from adenosine triphosphate to creatine, producing adenosine diphosphate and phosphocreatine.
Creatinine
Creatinine is a chemical substance excreted in the urine, which is derived from creatine and creatine phosphate. These substances serve to maintain adequate amounts of the substance adenosine triphosphate (ATP) which produces muscle contractions.
Crevicular
Crevicular means relating to any crevice. In dentistry, crevicular refers to the gingival crevice or subgingival space.
Critical current density
The critical current density represents the maximum current that can be transported by the film without losing superconductivity.
Critical transition temperature
The critical transition temperature represents the maximum temperature at which a material is superconducting.
CRN
Change Request Number
CRNE
Cosmic Ray Nuclei Experiment
Cross-coupling
Cross-coupling is a reflex that occurs when a visual scene which a subject is looking at is not aligned with the direction of gravity, for example, when the head is tilted from the vertical. Cross-coupling causes eye movements to align with the gravitational reference and not with the visual scene.
Cross-sectional Area
Cross-sectional Area (CSA) is the measurement of the area of a section formed by a plane cutting through an object, usually at right angles to an axis. For example, the cross-section of a muscle can be imaged using Magnetic Resonance Imaging (MRI). The cross section can be measured to determine the area and volume of the muscle.
CRR
Component Requirements Review
CRT
Cathode Ray Tube
CRT-KB
Cathode Ray Tube-Keyboard
CRU
Catalytic Research Unit
Cryogenic (CRYO)
Cryogenic means producing, or relating to the production of, low temperatures.
Cryogenically
Cryogenically refers to the storage or effects of materials in below-freezing temperatures. Biological specimens are sometimes stored in cryogenic conditions for long-term storage.
Crystallinity
Crystallinity refers to the crystal structure of the starch of a plant.
Crystallographic
Crystallographic means related to the study of crystal form and structure.
CS
Corrosive Solid
CSA
Cross-sectional Area (CSA) is the measurement of the area of a section formed by a plane cutting through an object, usually at right angles to an axis. For example, the cross-section of a muscle can be imaged using Magnetic Resonance Imaging (MRI). The cross section can be measured to determine the area and volume of the muscle.
CSCI
Computer Software Configuration Item
CSD
Contract Start Date
CSM
Command and Service Module
CSS
Core Segment Simulator
CST
Crew Software Training Aid
CTL
Control
CTPD
Crew Training and Procedure Division
CTPS
Cassette Tape Playback System
CTS
Crew Training Session
CTU
Central Timing Unit
Cultivate
To cultivate is to promote the growth of something (a biological sample, for instance).
Culture
A culture is a particular type of organism or cell growing in a laboratory nutrient medium.
Culture media
Culture media are nutrient substances, either solid or liquid, used for the cultivation, isolation, identification or storage of microorganisms or cells.
Culture medium
A culture medium is a nutrient substance, either solid or liquid, used for the cultivation, isolation, identification or storage of microorganisms or cells.
CUP
Control Unit and Processor
CV
Configuration Verification
CVT
Concept Verification Test
CW
Clockwise
CWEA
Caution and Warning Electronics Assembly
Cyanosis
Cyanosis is bluish discoloration of the skin and mucous membranes caused by an excess of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule.
Cyclic GMP
Cyclic guanosine monophosphate (Cyclic GMP) is a chemical substance that acts within cells to produce hormonal changes. It functions to allow hormones to affect only selected "target" cells to produce the desired changes in those cells.
Cystine
Cystine is a chemical substance which naturally occurs as a deposit in the urine, and can form a calculus (hard mineral formation) when deposited in the kidney.
Cytochemistry
Cytochemistry is the study of chemical compounds and their activities in living cells.
Cytochrome
Cytochrome is a chemical compound consisting of a protein linked to heme (the oxygen-carrier of the blood). Cytochromes are involved in many types of biological chemical reactions that support the life of cells.
Cytochrome oxidase
Cytochrome oxidase is an enzyme that acts as a chemical catalyst to facilitate chemical reactions occurring inside of cells as they consume nutrients and produce life-sustaining functions.
Cytogenetic
Cytogenetic refers to the science that links the study of inheritance (genetics) with that of cells (cytology) and is concerned mainly with the study of the chromosomes, their origin, structure, and functions.
Cytokines
Cytokines are chemicals involved in growth and regulation. They also influence bone resorption (breakdown) and formation.
Cytology
Cytology is the study of the structure and function of cells.
Cytomegalovirus
Cytomegalovirus is a group of herpetoviruses infecting man and other animals, many having special affinity for salivary glands, and causing enlargement of cells of various organs and development of characteristic inclusions in the cytoplasm or nucleus. Also known as visceral disease virus.
Cytoplasmic streaming
Cytoplasmic streaming is the movement or flow of cytoplasm, the living part of a cell external to the nuclear membrane.
Cytoskeleton
The cytoskeleton is a network of fibers running throughout the matrix of living cells that provides a framework for organelles, anchors the cell membrane, facilitates cellular movement, and provides a suitable surface for chemical reactions to take place.
Czapek Dox agar
Czapek Dox agar is a culture medium used to cultivate fungus species and to identify Aspergillus species.
D
Deck Area
D
Depth
D&C
Display and Control
D-A
Digital to Analog
D/L
Diameter to Length Ratio
D1
Deutsche Spacelab Mission - 1
DA
Desk Accessory (Macintosh)
DAC
Data Acquisition Camera
DAC
Digital to Analog Computer
DACh
Direct Access Channel
Damping
Damping is the dissipation of energy with time or distance. The term is generally applied to the attenuation of sound in a structure owing to the internal sound-dissipative properties of the structure or to the addition of sound-dissipative materials.
Deactivate means to render inactive or ineffective.
Dead space
Dead space is the area in the respiratory passages in which no gas exchange takes place.
Deafferentation
Deafferentation is a loss of the sensory nerve fibers, or their impulses, from a portion of the body.
Debris
Debris are the scattered remains of something broken or destroyed.
DEC
Digital Equipment Corporation
DEC net
Intercommunication Network Software from DEC
Decarboxylase
Decarboxylase is an enzyme that removes a molecule of carbon dioxide from a carboxylic group (e.g. from an a-amino acid, converting it into an amine).
Decompression
Decompression is the removal of pressure.
Decompression sickness (DCS)
Decompression sickness, also referred to as DCS, is a syndrome caused by bubbles of inert nitrogen gas forming in the tissues and bloodstream resulting from rapid changes in the ambient atmospheric pressure. DCS is manifested in two major forms, DCS I and DCS II. DCS I -- Decompression sickness involving only muscle and joint pain, fatigue and/or skin symptoms (itching, rash). DCS II -- Decompression sickness that includes symptoms involving the central nervous system, respiratory system or circulatory system.
Decondition
Decondition means to decrease in muscle strength or cardiovascular response.
Decontamination
Decontamination means to remove the contaminants or dangerous agents from something, e.g. buildings, clothing, the ground, etc.
DEF
Definition
Defibrillator
A defibrillator is a device which administers a controlled electric shock to restore normal heart rhythm in cases of cardiac arrest due to ventricular fibrillation (chaotic and abnormal pumping of the heart which does not allow the heart to pump blood effectively and is due to a disease or medical complication). The defibrillator administers the shock either through electrodes placed externally on the chest wall over the heart or directly to the heart after the chest has been opened surgically.
deg
Degree
Dehydration
Dehydration is the loss of water in body tissues. The condition may result from inadequate water intake and/or from excessive removal of water from the body; for example by sweating, vomiting or diarrhea.
Dehydroepiandrosterone (DHEA)
Dehydroepiandrosterone (DHEA) is a weakly androgenic steroid secreted largely by the adrenal cortex, but also by the testes. It is one of the principal components of urinary 17-ketosteroids.
DEMS
Dynamic Environment Measuring System
DEMUX,deMUX
Demultiplexer
Denitrogenation
Denitrogenation is the elimination of nitrogen from the lungs and body tissues by breathing gases devoid of nitrogen.
Densitometer
A densitometer is an electronic instrument used to measure the density, or degree of darkening, of a photographic film or plate, a liquid or material deposited on a chromatographic plate or electrophoresis medium, by photometrically recording its transparency.
Densitometry
Densitometry is the measurement of the density or compactness of bone. It is also an indirect method of determining body composition; using this method, percentage of body fat is computed from bone density (the ratio of body weight to body volume).
Dental caries
Dental caries is a localized, progressively destructive disease of the teeth that starts at the external surface or enamel and dissolves the inorganic components. Organic acids are produced on or next to the tooth by the enzymatic action of microorganisms in the bacterial plaque on carbohydrates. The initial demineralization is followed by an enzymatic destruction of protein. Cavities and bacterial infection follow. In the dentin, demineralization in the tubules is followed by bacterial invasion and destruction of the organic matrix. Untreated dental caries progresses to the pulp, resulting in infection and its consequences.
Dental plaque
In dentistry, dental plaque is a mass of microorganisms attached to the surface of a tooth. Depending on bacterial activity and environmental factors, it can result in caries, calculus or inflammatory changes in adjacent tissue.
Dental prophylaxis (plural prophylaxes)
Dental prophylaxes are a series of procedures whereby calculus, stain, and other accretions are removed from the clinical crowns of the teeth, and the enamel surfaces are polished.
Dental pulp
Dental pulp (pulpa dentis) is the soft tissue within the pulp cavity, consisting of connective tissue containing blood vessels, nerves, and lymphatics, and at the periphery a layer of odotolasts capable of internal reair of the dentin.
Deoxypyridinoline
In the process of bone resorption, the type I collagen cross linking molecule deoxypyridinoline (Dpd) is released into the circulation and cleared by the kidney. Dpd in urine can be measured as a specific marker of bone resorption.
Deoxyribonucleic acid (DNA)
Deoxyribonucleic acid (DNA) is a complex molecule found in the chromosomes of almost all organisms which acts as the chemical storage for primary genetic material. DNA contains the chemical "code" which allows traits and inherited characteristics to be passed down from organism to organism.
DEP
Dedicated Experiment Process
Deploy
To deploy is to station or distribute systematically over an area (in preparation for operation or activity).
Deposition
Deposition is the precipitation of mineral matter from solution, such as the deposition of agate, vein quartz, etc.
Dermatitis
Dermatitis is the inflammation of skin.
Dermatophyte
A dermatophyte is a fungus that causes infections of the skin, hair and/or nails, i.e., keratinized tissue.
DES
Data Exchange System
Desc
Description
DESCPT
Description
Desiccation
Desiccation means dehydration.
Desorb
Desorb means to remove by the reverse of adsorption or absorption.
DEST
Destination
Detailed Supplementary Objective (DSO)
A Detailed Supplementary Objective (DSO) is a NASA-sponsored investigation performed voluntarily by Space Shuttle crewmembers, who serve as the test subjects. These studies are designed to require minimal crew time, power and stowage. Biomedical DSOs focus on operational concerns, including space motion sickness, cardiovascular deconditioning, muscle loss, changes in coordination and balance strategies, radiation exposure, pharmacokinetics and changes in the body’s biochemistry. Key hardware and procedures have been tested and verified as DSOs prior to use in support of more costly, complex life sciences investigations. Data may be collected before, during and after flight, and usually subjects from more than one mission participate in each DSO. Some DSOs were also part of the Extended Duration Orbiter Medical Project.
Deuterium
Deuterium is an isotope of hydrogen (same number of protons in the nucleus, but a different number of neutrons).
DEV
Development
Development Test Objective (DTO)
At the beginning of the Shuttle Program, the Space Transportation System (STS) Program Office established a procedure for testing and refining Orbiter and subsystem performance capabilities, and for evaluating new hardware and procedures. Procedures involving the Orbiter, its subsystems, and its support equipment were designated Development Test Objectives (DTOs). All other operationally relevant procedures were classified as Detailed Supplementary Objectives (DSOs).
Developmental biology
Developmental biology research is concerned with the influences of gravity and microgravity on reproduction, differentiation, growth, development, life span, aging and subsequent generations of animals.
Dewar
The Dewar is a thermos-like container used to store protein samples and keep them frozen until the liquid nitrogen thaws.
Dexamethasone
Dexamethasone is a glucocorticoid which is prescribed in the treatment of inflammatory conditions.
Dexterity
Dexterity is skill in using the hands or body.
Dextroamphetamine
Dextroamphetamine is a form of amphetamine, a drug that stimulates the central and peripheral nervous systems.
Dextroamphetamine sulfate
Dextroamphetamine sulfate is a central nervous system stimulant.
Dextrose
Dextrose is a simple sugar found in the blood (also known as glucose).
DFAST
Data Flow and Analysis Timeline
DFI
Dedicated Flight Instrumentation
DFPT
Delayed Flight Profile Test
DFRC
Dryden Flight Research Center
DG
Diagnostic
DGDSO
Ground Data System Officer
DGP
Diagnostic Package
DHF
Data Handling Function
DHU
Data Handling Unit
DI
Data Integrator
DI
Discrete Input
Dialysis
Dialysis is a form of diffusion, i.e., a form of filtration to separate a crystalloid from colloid substance in a solution by interposing a semi-permeable membrane between the solution and water. The crystalloid substances pass through the membrane into the water on the other side, the colloids do not.
Dialyze
Dialyze means to prepare by diffusion through a semipermeable membrane.
Diaphragm
A diaphragm is a thin dome-shaped skeletal muscle that separates the thoracic and abdominal cavities. The diaphragm plays an important role in breathing: it contracts with each inspiration, becoming flattened downward and increasing the volume of the thoracic cavity so that air is drawn into the respiratory tract, and then, with expiration, it relaxes and is restored to its dome shape.
Diastole
Diastole is the phase of the heart during which the heart muscle relaxes, causing blood to fill the heart chambers.
Diastolic blood pressure
Diastolic blood pressure is the blood pressure measured during diastole, or the dilation of the heart cavities, during which they fill with blood. The lowest blood pressure measured in the large arteries is about 80 millimeters of mercury under normal conditions for a young, adult male.
Dichlorodifluoromethane
Dichlorofluoromethane is a chlorofluorocarbon derived from methane (freon). Freons are gaseous compounds used as refrigerants, cleaning solvents and aerosol propellants.
Didactic
Didactic means pertaining to instruction or teaching.
Diencephalon
The diencephalon is the portion of the embryonic brain that develops into the thalamus, hypothalamus, and associated structures, all of which make up the diencephalon (hindbrain) in the adult. It includes structures important in the visual pathway. Some sources consider the adult diencephalon to be part of the brainstem.
Differential count
A differential count is an estimate of the percentage of white blood cell types which make up the total white blood cell count.
Differentiation
Differentiation, in embryology, is the process in embryonic development during which unspecialized cells or tissues become specialized for particular functions. Differentiation, in oncology, is the degree of similarity or difference of tumor cells to the structure of the organ from which the tumor arose.
Diffusing capacity
The diffusing capacity is the volume of a gas that diffuses through a membrane each minute for a pressure difference of 1 mmHg.
Diffusion
Diffusion generally refers to the spreading out or dispersing of a material. Chemical diffusion is a passive process in which there is a net or greater movement of molecules or ions from a region of high concentration to a region of low concentration until equilibrium is reached.
Diffusion coefficient
The diffusion coefficient is a numerical measure of the diffusion property that is constant for a specified system. Diffusion refers to the spreading out or dispersing of a material. Chemical diffusion is a passive process in which there is a net or greater movement of molecules or ions from a region of high concentration to a region of low concentration until equilibrium is reached.
Digestive
Digestive is a term relating to the digestive system, which comprises the digestive tract from the mouth to the anus and all associated glands and organs.
Digital
Digital is a term for a transmission mode in which data is measured in discrete intervals. Digital electronics systems measure voltage being turned on an off through a series of numbers using only 1s and 0s.
DIL
Discrete Inputs, Low Level
DIL
Digital Image Library
Dilatancy
Dilatancy is the property of increasing viscosity with an increase in applied force, such as a shear force or pressure caused by expansion of volume. Cytoplasm exhibits dilatancy.
Dilation
Dilation is the physiologic, pathologic, or artificial enlargement of a cavity, canal, blood vessel or opening.
Dilution series
A dilution series is a method for counting the number of viable cells in a suspension; a sample is diluted to the point where an aliquot, when plated, yields a countable number of separate colonies.
Dimethyl sulfoxide (DMSO)
Dimethyl sulfoxide (DMSO) is a penetrating solvent, that enhances the absorption of therapeutic agents and has been proposed as an effective analgesic and anti-inflammatory agent in arthritis and bursitis.
Dioctyl phthalate (DOP)
Dioctyl phthalate (DOP) is used as a plasticizer in a variety of products. These products include polyvinylchloride (PVC) and other polymers such as rubber, cellulose and styrene. A number of packaging materials and tubings used in the production of foods and beverages also contain DOP. Disposal of these products (incineration, landfill, etc.) results in the release of DOP into the environment. Acute exposure to DOP can result in mild gastrointestinal disturbances, nausea and vertigo. DOP may also have the potential to cause cancer from long-term exposure at levels above the Environmental Protection Agency's (EPA) set Maximum Contaminant Level (MCL).
Diphtheria
Diphtheria is an infection caused by the highly potent toxin of the bacterium Corynebacterium diphtheriae, which produces degeneration in peripheral nerves, heart muscle and other tissues.
Diphtheroid
A diphtheroid is a bacterium (especially genus Corynebacterium) that resembles the bacterium of diphtheria but does not produce diphtheria toxin.
Diploid
Diploid means denoting the state of a cell containing twice the normal gametic number of chromosomes, one member of each chromosome pair derived from the father and one from the mother; the normal chromosome complement of somatic cells.
Dipyridamole
Dipyridamole is a coronary vasodilator which is prescribed for the long term treatment of angina.
Discocyte
A discocyte is a red blood cell that is in the normal, biconcave disc shape.
Distal
Distal means anatomically situated away from the origin or point of attachment, or from the middle line of the body. It is specifically applied to the extremity or distant part of a limb or organ. For example, the fingers are the most distal portion of the arm in relation to the torso.
Diuresis
Diuresis is the increased secretion of urine by the kidneys. This normally follows the intake of more fluid than the body requires, but can be stimulated by administering a drug called a diuretic or by the fluid shift that occurs in microgravity.
Diurnal
Diurnal means pertaining to or occurring in the daytime; opposite of nocturnal. Diurnal also means repeating once each 24 hours.
DL
Dedicated Laboratory
DL-1
Dedicated Laboratory-1 (Mission)
DLSL
Dedicated Life Sciences Laboratory
DM
Docking Module
DM
DM stands for the diffusing capacity of the alveolar capillary membrane, the outer membrane of the smallest blood vessels, called capillaries, in the lung.
DMA
Direct Memory Access
DMIS
Data Management Information System
DMOO
Data Management and Operations Office
DMP
Data Management Plan
DMS
Data Management System
DN
Discrepancy Notice
DNA fingerprinting
DNA fingerprinting is a method used to identify individuals within a species. The DNA fingerprint itself is the individual-specific autoradiographic banding pattern (shown by electrophresis) that is produced when DNA is digested with a restriction endonuclease.
DO
Discrete Output
DOD
Department of Defense
Doff
To doff is to remove an article of clothing.
DOH
Discrete Outputs, High Level
DOL
Discrete Outputs, Low Level
DOMSAT
Domestic Satellite
Don
To don is to put on an article of clothing to wear.
Doppler ultrasound
Doppler ultrasound is a procedure that uses sound waves to evaluate soft-tissue organs in the body, such as the liver, kidneys and gallbladder. The ultrasound machine is made up of computers and handheld instruments called transducers. A transducer looks like a wand or microphone. Warm gel is used to remove the air between the skin and the transducer. The wand is moved across the skin, producing a picture on the computer screen.
Dorsal
Dorsal means relating to or situated at or close to the back of the body or to the posterior part of an organ.
Dorsiflexion
Dorsiflexion is the backward flexion of the foot, toes, hand or fingers, (bending toward the upper surface).
Dorsiflexor
The dorsiflexor is a muscle which turns the foot, toes, hands or fingers upward towards the upper surface.
Dorsomedial
The term dorsomedial is used in medicine to refer to the central, back region of the body area being discussed. The term comes from the Latin dorso (posterior or back) and medial (relating to the middle or center). Thus the term “dorsomedial aspect of the thigh” means centrally located behind the thigh.
Dose equivalent
A dose equivalent is the absorbed radiation dose adjusted to allow for the biological harmfulness of different kinds of radiation; it is measured in sieverts (Sv).
Dose rate
Dose rate is the ionizing radiation dose delivered per unit of time.
Dosimeter
A dosimeter is a device used to record the amount of radiation received by workers from X-rays or other radiation, usually consisting of a small piece of photographic film in a holder attached to the clothing. At regular intervals the film is examined to determine the amount of radiation it (and therefore, the wearer) has received.
Dosimetry
Dosimetry is the accurate determination of radiation dosage, i.e., the quantity of radiation received over a given period of time.
DOSR
Design and Operations Status Review
DOT
Department of Transportation
Doubly labeled water
Doubly labeled water is a method of measuring metabolism by using two stable, non-radioactive chemical isotopes: deuterium (2H) and oxygen (18O). This method has the advantage that the two metabolic processes in the body involving hydrogen and oxygen can be monitored simultaneously. Deuterium leaves the human body in urine, while the labeled oxygen is found in urine and exhaled CO2. The difference between the two isotopes found in the urine sample is equal to the rate of CO2 production, which indicates energy consumption.
DP
Data Processing
DP
Double Precision Floating Point
DPI
Dots Per Inch
DPS
Data Processing Supervisor
DR
Data Requirement
DR&C
Data Research and Control
DRAM
Dynamic Random Access Memory
DRD
Data Requirements Document
Drechslera
Drechslera is a saprobic genus of fungi, frequently recovered in the clinical laboratory, characterized by conidia attached to a zigzagged conidiophore. Species in the genus may cause disease in humans, cats, and horses.
DRF
Data Request Form
DRIP
Data Requirements Implementation Plan
DRL
Data Requirement List
Drosophila
Drosophila are a species of fruit flies. Drosophila are often used in genetic research because the larvae possess large chromosomes in their salivary glands. Fruit flies have a short life cycle and produce a large number of offspring, which makes them an ideal species for scientific study.
DRS
Data Base Software (Data Retrieval System)
DRS
Data Requirement Status (Manager)
DRTS
Data Relay Tracking Satellite
DS
Discipline Scientist
DSAD
Data Systems and Analysis Directorate
DSIP
Data Systems Implementation Plan
DSN
Deep Space Network
DSP
Data System Plan
DSPL
Display
DSR
Database Support Request
DSSP
Data Systems Support Plan
DSSR
Data Systems Support Request
DT
Delayed Time
DT
Dynamic Environment Measuring System Tester or DEMS Tester
DTA
Differential Thermal Analysis
DTE
Digital Television Equipment
DTP
Desktop Publishing
DTS
Data Transmission System
Dual Energy X-ray Absorptiometry (DEXA)
Dual Energy X-ray Absorptiometry (DEXA) provides accurate measurements of whole and regional body composition (fat, bone and muscle tissue).
Ductile
Ductile is the ability of a substance to be hammered thin.
DVU
Design Verification Units
DWG
Drawing
DWG #
Drawing Number
Dynamometer
A dynamometer is an instrument used to measure the force of muscular contraction.
Dysbarism
Dysbarism is a reaction to sudden change in ambient pressure, such as rapid exposure to the lower atmospheric pressures of high altitudes. It is marked by symptoms similar to those of decompression sickness.
Dysfunction
A dysfunction is an abnormal function, that is either diseased, faulty or bad.
Dysrhythmia
Dysrhythmia is any abnormality in the rate, regularity or sequence of heart activity.
E
Estimated
E-rosette
E-rosette is a technique used to identify cell surface receptors. Signal cells, carrying a receptor-binding substance on its surface, are mixed with receptor-bearing cells. When the receptor-bearing cells bind to the signal cells, they form “rosettes."
ea
Each
EAFB
Edwards Air Force Base
EAPC
Equivalent Additions per Cycle
EAV
Experiment Assembly and Verification
EBA
Electron Beam Accelerator
EC
Experiment Computer
EC-HRM
Experiment Computer - High Rate Multiplexer
ECAS
Experiment Computer Application Software
Eccentric
Eccentric muscle movement causes a lengthening of the muscle, that is, movement of a muscle away from the body.
ECDS
Experiment Command and Data System
ECE
Experiment Checkout Equipment
ECE
Experiment Coordinating Engineer
ECF
Electro-Conductive Film
ECG
Electroephitaxial Crystal Growth
Echinocyte
An echinocyte is a red blood cell that has changed from the normal, biconcave disc shape to a sphere with short, sharply pointed projections. Aging of blood in circulation, in a tube or on a slide is the most common cause of the discocyte to echinocyte transformation.
Echocardiogram
An echocardiogram is an image of the heart and major blood vessels produced by echocardiograpy.
Echocardiographic
Echocardiographic means pertaining to an echocardiograph, an instrument used to produce ultrasound images of the heart and major blood vessels, or to the record it produces or the process of making the record.
Echocardiography
Echocardiography is the use of ultrasound (sound waves at extremely high frequencies) to produce images of the heart and major blood vessels.
ECIO
Experiment Computer Input Output
ECLS
Environmental Control and Life Support
ECLSS
Environmental Control and Life Support Subsystem
ECLSS
Environmental Control and Life Support System
ECMA
European Computer Manufacturing Association
ECO
Engineering Change Order
Ecological
The term ecological relates to the total complex of interrelationships among living organisms, encompassing the relations of organisms to each other, to the environment, and to the entire energy balance within a given ecosystem.
Ecology
Ecology is the branch of biology concerned with studying the interrelationships of living organisms, specifically their relationships to each other and to the environment.
ECOS
Experiment Computer Operating System
ECP
Engineering Change Proposal
ECR
Engineering Change Request
ECS
Environmental Control Subsystem
ECS
Environmental Control System
Ectopic
Ectopic means "out of place" and is said of an organ which is not in its proper position, or of a pregnancy occurring elsewhere than in the cavity of the uterus. In cardiography, it denotes a heart beat that has its origin in some abnormal focus other than the sinoatrial node (the area of the heart where heart beats normally originate).
ED
Experiment Document
ED
Experiment Definition
EDAX
Energy Dispersive X-Ray Analysis System
EDB
Engineering Data Base
EDC
Experiment Development Center
EDCR
Engineering Design Change Request
Edema
An edema (or dropsy) is an excessive accumulation of fluid in the body tissues. The resultant swelling may be local, associated with an injury or inflammation, or general, as occurs in heart or kidney failure.
EDF
Engineering Data Function
EDIS
Experiment Data Interface System
EDL
Linkage Editor
EDOMP
Extended Duration Orbiter Medical Project
EDP
Electronic Data Processing
EDR
Experiment Design Review
EDRS
European Data Relay Satellite
EDU
Experiment Development Unit
EED
Electrical Explosive Device
EEE
Electrical, Electronics, and Electromechanical
EEVT
Electrophoresis Equipment Verification Test
Effective renal plasma flow (ERPF)
Effective renal plasma flow (ERPF) is often also referred to as plasma clearance, and refers to the ability of the kidneys to clean or clear the plasma of unwanted substances. It is a rate, usually expressed in milliliters of cleared substances per minute (ml/min).
Effector
An effector is a cell or organ that produces a physiological response when stimulated by a nerve impulse. Examples of effectors include muscles and glands.
Efferent
Efferent means conducting (fluid or a nerve impulse) outward from a given organ or part thereof, e.g. the efferent connections of a group of nerve cells, efferent blood vessels, or the excretory duct of an organ.
Efficacy
Efficacy is the power or capacity to produce a desired effect; effectiveness.
Effluent
Effluent refers to something that flows out or forth.
EFS
Experiment Flight Software
Egocentric
Egocentric means to place extreme concentration or attention on one's self. Egocentric motor strategies are those in which the subject concentrates on a body frame of reference rather than on the external world.
Egress
Egress is the act of getting out of a structure, usually a spacecraft in this database. As a verb, it means to get out of a spacecraft.
EGSE
Electrical Ground Support Equipment
EI
Equipment Item
EI
Experiment Integrator
EIA
Electronic Industry Association
Eicosanoid
Eicosanoid is a lipid mediator of inflammation derived from the 20-carbon atom arachidonic acid (20 in Greek is "eicosa") or a similar fatty acid. The eicosanoids include the prostaglandins, prostacyclin, thromboxane, and leukotrienes.
EIE
Experiment Interface Engineer
EIS
Electrical Integration System
EISB
Electronics Instrument Services Branch
EIU
Engineer Interface Unit
Ejection fraction
The ejection fraction is the fraction of the end-diastolic volume of the heart that is ejected from the ventricles during systole.
Ejection time
Ejection time is the period during which, in the heart, ventricular pressures push the heart valves open and the blood in the ventricles is forced into the aorta, the main artery leading from the heart.
EL
Elevation
Elbow extensor
The elbow extensor is the muscle (called the triceps brachii) that extends the elbow joint.
Elbow flexor
The elbow flexor is the muscle (called the biceps brachii) which acts to flex the elbow.
Electrical systole
Electrical systole is the electrical discharge that precedes the contraction of the heart muscle. It is also known as the QRS complex. This electrical discharge depolarizes the myocardium (heart muscle) and results in mechanical systole or the muscular contraction of the heart.
Electro-oculogram (EOG)
An electro-oculogram is a record of the electric currents that result from changes in standing potential between the front and back of the eyeball as the eyes move.
Electro-oculograph
An electro-oculograph is an instrument used to record eye movements by measuring small electrical charges with tiny electrodes attached to the skin at the inner and outer corners of the eye.
Electro-oculography (EOG)
Electro-oculography (EOG) is the method of recording eye movements by placing electrodes on the skin around the eye. The electrodes measure the small changes in the electrical potentials in the skin as the eyeball moves.
Electro-osmosis
Electro-osmosis is the diffusion of a substance through a membrane in an electrical field.
Electrocardiogram (ECG or EKG)
An electrocardiogram (ECG or EKG) is a graphic record of the heart's electrical currents.
Electrocardiograph
An electrocardiograph is an instrument used to record the potential of electrical currents that traverse the heart and initiate its contraction.
Electrode
An electrode is a small conductive device used to establish electrical contact with the body (animal or human). The electrical current generated by the human body is conducted through the electrode to an instrument that records the electrical potential of these currents. Instruments that use electrodes include the electrocardiograph (ECG), electroencephalograph (EEG), electrooculograph (EOG) and electromyograph (EMG).
Electroencephalogram (EEG)
An electroencephalogram (EEG) is a graphic record of the electrical activity in the brain obtained by an electroencephalograph. The pattern of the EEG reflects the state of the patient's brain and the level of consciousness in a characteristic manner. A recording of the electrical impulses of the brain can be used to diagnose certain diseases (such as epilepsy), furnish information regarding sleep and wakefulness, and confirm brain death.
Electrofusion
Electrofusion is the process of fusing two separate cells by applying an electric current. For example, plant cell protoplasts of two different species of sunflowers were fused during the D-2 Space Shuttle mission by the application of electric pulses of short duration and high intensity. As the cells came in contact with each other, their cell membranes combined, forming a single larger cell, or hybrid, with new characteristics distinct from the two original parent cells.
Electrogenesis
Electrogenesis refers to the creation of electrical energy.
Electrolysis
Electrolysis is the decomposition of a salt or other chemical compound by means of an electric current.
Electrolyte
An electrolyte is an element or compound that, when dissolved or melted in water or other solvent, dissociates into ions and is able to conduct electric current. Electrolyte concentrations differ between the blood plasma, interstitial fluid and cell fluid, which affects the movement of substances between these fluids. Proper quantities of principal electrolytes and balance among them are critical to normal metabolism and function.
Electromagnetic interference (EMI)
Electromagnetic interference (EMI) is any electromagnetic disturbance that interrupts, obstructs, or otherwise degrades or limits the effective performance of electronics/electrical equipment. It can be induced intentionally, as in some forms of electronic warfare, or unintentionally, as a result of spurious emissions and responses, intermodulation products, and the like.
Electromyogram (EMG)
An electromyogram (EMG) is a record of electrical currents generated in an active muscle.
Electromyographic
Electromyographic means pertaining to an electromyograph (EMG), an instrument that records electrical currents generated in an active muscle, or to the record it produces or the process of making the record.
Electromyography
Electromyography is the recording of electrical currents generated in an active muscle using an instrument called an electromyogram (EMG). EMG recordings can be used to ascertain causes of muscular weakness, paralysis, involuntary twitching, and abnormal levels of muscle enzymes; EMGs can also be used as part of biofeedback studies.
Electron microscopy
Electron microscopy is inspection with an electron microscope. An electron microscope utilizes streams of electrons deflected from their course by an electrostatic or electromagnetic field for magnification of objects. The final image is viewed on a fluorescent screen or recorded on a photographic plate. Because of greater resolving power, images may be magnified up to 40,000 diameters, more than any other type of microscope.
Electron spectroscopy for chemical analysis (ESCA)
Electron spectroscopy for chemical analysis (ESCA, also known as X-ray photoelectron spectroscopy or XPS) is a surface analysis technique used for obtaining chemical information about the surfaces of solid materials. An X-ray beam excites a solid sample, resulting in the emission of photoelectrons. An energy analysis of these photoelectrons provides information about the elements and chemical bonding on the surface of the sample.
Electronystagmograph
An electronystagmograph is an electronic device used to collect data on the nystagmic properties of eye movement by detecting and recording the nerve signals that cause such movements.
Electrophoresis
Electrophoresis is the technique of separating electrically charged particles, particularly proteins, in a solution by passing an electric current through the solution. The rate of movement of the different components depends upon their charge, so that they gradually separate into bands. Electrophoresis is widely used in the analysis of body chemicals, such as the analysis of the different proteins in blood serum.
Ellipsometry
Ellipsometry is the measurement of the change in ellipticity (the quality of asymmetrical intensity distribution in a laser beam, as opposed to a circular distribution) of an optically polarized light beam after reflection from a surface in a particular manner.
ELM
Experimental Logistics Module
Elodea
Elodea is any of a small American genus of submerged aquatic monocotyledonous herbs.
ELS
Emergency Landing Site
ELT
Emergency Locater Transmitter
ELV
Expendable Launch Vehicle
EM
Electromagnetic
EM
Electromagnetic Energy
EM
Engineering Model
EM
Exception Monitor
EM
Experiment Manager
Embryo
An embryo is an animal at the early stage of development, before birth.
Embryo sac
An embryo sac is a large cell that develops in the ovule of flowering plants. It contains the egg cell which, when fertilized, becomes an embryo, and then, eventually, a seed.
Embryogenesis
Embryogenesis is the formation and development of an embryo.
Embryological
Embryological refers to an embryo, an animal at the early stage of development before birth.
Embryonate
Embryonate means containing an embryo.
Embryonic
Embryonic refers to an embryo, an animal at the early stage of development before birth.
Emittance is a rating of the ability of a material to give off heat as radiant energy. The emissivity of a material is expressed as a fraction. Emittance values range from 0.05 for brightly polished metals to 0.96 for flat black paint.
EMP
Engineering Management Plan
Emphysema
Emphysema is a pulmonary disorder involving over-distention and destruction of the air spaces in the lungs.
EMS
Electromagnetic Susceptibility
EMS
Engineering Master Schedule
EMU
Extravehicular Mobility Unit
End diastolic cardiac volume
End diastolic volume is the volume measured in each ventricle at the end of diastole (period of the heart's relaxation), which normally increases to about 130 ml.
End systolic cardiac volume
End systolic cardiac volume is the volume measured in each ventricle at the end of systole (period of the heart's contraction), which normally decreases to about 60 ml.
End tidal carbon dioxide
End tidal carbon dioxide is the concentration of carbon dioxide in exhaled breath at the end of each expiration.
Endemic
Endemic, in relation to a microorganism or disease, means indigenous to a geographical area or population.
Endocrine
Endocrine means secreting internally, most commonly into systemic circulation.
Endocrine glands
The endocrine glands manufacture one or more hormones and secrete them directly into the bloodstream. Endocrine glands include the pituitary, thyroid, parathyroid, adrenal, ovary, testis, placenta and part of the pancreas.
Endocrine secretions
The endocrine secretions are hormones secreted directly into the bloodstream and not through a duct to the exterior.
Endocrine system
The endocrine system refers to all of the body's hormone-secreting glands. This system works in conjunction with the nervous system to control the production of hormones and their release into the circulatory system.
Endocrinology
Endocrinology is the study of the structure and functions of the endocrine glands and the diagnosis and treatment of disorders of the endocrine system.
Endosteal surface
The endosteal surface is the inside surface of bones which border the bone marrow cavity.
Endothelial cells
Endothelial cells are the inside cellular lining of a tissue.
Endotoxin
An endotoxin is a poison found in the cell membrane of some gram-negative bacteria, which is released when the cell is damaged or destroyed.
Enema
Enema is the injection of a liquid into the rectum through the anus for cleansing, as a laxative, or for other therapeutic purposes.
Energy expenditure
Energy expenditure is the amount of metabolic energy used, or calories burned, by an individual under specified conditions.
Energy metabolism
Energy metabolism refers to the transformation of chemical energy from food to mechanical energy or heat.
Energy-dispersive spectroscopy
Energy-dispersive spectroscopy is analysis of the chemical elements in a structure by directing a beam of electrons at the structure and examining the energy and intensity distribution of the X-rays thus produced.
ENG
Electronsystematography
ENG
Engineer
ENG
Electronsyatmography
Engorgement
Engorgement means distention or vascular congestion of body tissues.
Enteric
Enteric means relating to the intestine.
Enteric cytopathogenic human orphan (ECHO) virus
The enteric cytopathogenic human orphan (ECHO) virus is an enterovirus isolated from man that belongs to the family Picornaviridae. While there are several inapparent infections, certain of the several serotypes are associated with fever and aseptic meningitis, and some appear to cause mild respiratory disease.
Enteritis
Enteritis is the inflammation of the intestine, especially of the small intestine.
Enterobacter
Enterobacter is a genus of aerobic, facultatively anaerobic, nonsporeforming, motile bacteria containing Gram-negative rods. The cells are peritrichous, and some strains have encapsulated cells. Glucose is fermented with the production of acid and gas. These organisms occur in feces, sewage, soil, water, and dairy products and are recognized as the agent of common infections of the urinary tract, lungs, or blood.
Enterococcus faecalis
Enterococcus faecalis is a species of non-motile bacteria having gram-positive spherical cells, occurring in chain-like groups. They are commonly found in the intestinal tract of humans.
Enterovirus
Enterovirus is any of a group of picornaviruses (small RNA-containing viruses such as the poliomyelitis virus) that typically occur in the gastrointestinal tract but may be involved in respiratory ailments, meningitis and neurological disorders.
Environmental monitoring
Environmental monitoring is the quantification and tracking of physical, chemical, biological and radiological factors in a defined environment, such as the interior of a spacecraft.
Enzyme
An enzyme is usually a protein that, in small amounts, speeds up the rate of a biological reaction without itself being used up in the reaction (i.e., it acts as a catalyst). For example, enzymes present in the digestive juices of the stomach break down food into simpler compounds to be absorbed into the body.
Enzyme histochemistry
Enzyme histochemistry is the study of the chemistry of enzymes.
Enzyme Linked Immunosorbent Assay (ELISA)
Enzyme Linked Immunosorbent Assay (ELISA) is used for diagnosis of specific infectious diseases. An enzyme is used as the indicator system; when the enzyme and the antigen-antibody complex bind, a color indicator or other easily recognizable sign occurs.
EO
Engineering Order
EOD
Earth Observations Division
EOM
Earth Orbiting Mission
EOM
End of Message
EOM+
End of Mission + (Days)
EOS
Earth Observation Satellite
EOS
Earth Observing System
Eosinophil
An eosinophil is a variety of white blood cell distinguished by the presence in its cytoplasm of coarse granules; its function is poorly understood, but it is known to be capable of ingesting foreign particles, is present in large numbers in lining or covering surfaces of the body, and is involved in allergic responses.
EPBD
Electric Power Branching Distributor
EPBD
Experimental Power Bus Distribution
EPC
Experiment Procedures Coordinator
EPDB
Electric Power Distribution Box
EPDS
Experimental Power Distribution System (Subsystem)
EPH
Experiment Peculiar Hardware
Ephemeral
Ephemeral is anything that lasts for a brief time; transitory.
Ephyrae
Ephyrae are free-swimming larvae of a jellyfish that result from the strobilation (division into segments) of a larval polyp (juvenile form of a jellyfish).
Epidemiological
Epidemiological means of or relating to epidemiology, a branch of medical science in which the incidence, distribution and control of disease is studied. This not only applies to the study of such classic epidemics as plague and cholera, but also includes all forms of disease that relate to the environment and ways of life, such as links between smoking and cancer, diet and coronary disease, and communicable diseases.
Epinephrine
Epinephrine (also called adrenaline) is a hormone secreted by the adrenal medulla section of the adrenal gland and released primarily in response to hypoglycemia; it is also produced as a synthetic drug. A powerful vasopressor substance, epinephrine acts to increase blood pressure and stimulate the heart muscle, accelerating the heart rate and increasing cardiac output.
EPIRB
Emergency Position Indicating Radio Beacon
Epithelial
An epithelial tissue is a tissue that covers the external surface of the body and lines hollow structures inside the body.
EPO
Element Project Office
EPO
Experiment Planning Officer
EPOC
External Payload Operations Center
EPP
Experiment Preparation Program
EPROM
Erasable Programmable Read Only Memory
EPS
Electrical Power System
EPSP
Experiment Power Switching Panel
Epstein-Barr virus
The Epstein-Barr virus is a herpesvirus that causes infectious mononucleosis (mono). It is also found in cell cultures of Burkitt’s lymphoma and is associated with nasopharyngeal carcinoma.
Equilibrium
Equilibrium is a state of balance, a condition in which the contending forces are equal.
EQUIP
Equipment
ER
Early Release
ERA
Exobiology and Radiation Assembly
ERAN
Early Release Alteration Notice
ERBE
Earth Radiation Budget Experiment
ERD
Experiment Requirements Document
EREP
Earth Resources Experiment Package
Ergometer
An ergometer is a rotary pedal device (i.e., static exercise bicycle) that provides a calibrated, or specific, resistance. The force required to overcome the resistance is measured as work.
Ergometry
Ergometry is the study of physical work activity, including work performed by specific muscles or muscle groups. The study may involve testing with equipment, such as stationary bicycles, treadmills, or rowing machines.
ERT
Experiment Review Team
ERTS
Earth Resources Technology Satellite
Erythrocyte
An erythrocyte is more commonly known as a red blood cell, which is the most numerous type of blood cell. Erythrocytes contain the red pigment hemoglobin and are responsible for oxygen transport. In humans, the number of erythrocytes in the blood varies between 4.5 and 5.5 million per cubic millimeter. They survive for about four months and are then destroyed in the spleen and liver.
Erythrokinetics
Erythrokinetics is a quantitative, dynamic study of in vivo (occurring within the body) production and destruction of erythrocytes (red blood cells).
Erythron
Erythron is an element of the blood-forming system of the body that is involved in the production of red blood cells; it is not a single organ but is dispersed throughout the blood-forming tissue of the bone marrow.
Erythropoiesis
Erythropoiesis is the process of red blood cell production, which normally occurs in the blood-forming tissue of the bone marrow.
Erythropoietin
Erythropoietin is a hormone secreted by certain cells in the kidney in response to a reduction in the amount of oxygen reaching the tissues; it stimulates red blood cell production.
ESD
Electrostatic Discharge
ESFS
Experiment Simulation Flight Software
ESI
Electrical System Integration
ESI
Experiment Support Item
ESOP
Experiment System for Orbiting Primate
ESP
Experiment Switching Panel
ESR
Engineering Support Agency
ESRD
Experiment Simulator Requirements Document
ESS
Experiment Schedule Service (database)
ESS
Energy Storage Subsystem
ESS
Experiment Support Scientist
Est
Estimate
EST
Eastern Standard Time
ESTEC
European Space Research & Technology Center
Esterase
Esterase is a generic term for enzymes that catalyze the hydrolysis of esters.
ESU
Experiment Checkout Unit
ET
External Tank
ETA
Expected Time of Arrival
Ethanol
Ethanol is a clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is also widely used as a solvent and preservative in pharmaceutical preparations, as well as serving as the primary ingredient in alcoholic beverages.
Ethylene glycol
Ethylene glycol is a compound containing two hydroxy groups bound to adjacent carbon atoms; it is the simplest glycol and has the molecular formula HOCH2CH2OH. Ethylene glycol is used in antifreeze and other products.
Ethylenediaminetetraacetic acid (EDTA)
Ethylenediaminetetraacetic acid (EDTA) is a chelating agent, generally used in the form of a sodium salt. In biochemical research, it is used to remove Mg2+, Fe2+, etc. from reactions affected by such ions. It is also used as a water softener, an anticoagulant, and a stabilizing agent for drugs that decompose rapidly in the presence of traces of metal ions . EDTA is also used to treat lead poisoning.
Etiocholanolone
Etiocholanolone is a metabolite of adrenocortical and testicular hormones and is an important 17-ketosteroid. It produces fever when given to humans.
Etiology
Etiology refers to the study of all factors that may be involved in the development of a disease, including susceptibility of the patient, the nature of the disease agent, and the way in which the patient's body is invaded by the agent.
ETO
Estimated Time of Operation
ETR
Eastern Test Range
EU
Electrophoresis Unit
EUE
Experiment Unique Equipment
EUH
Experiment Unique Hardware
EURECA
European Retrievable Carrier
European Space Agency (ESA)
The European Space Agency (ESA) sponsors space research and technology among 13 member states (Austria, Belgium, Denmark, France, Germany, Ireland, Italy, The Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom), one associate member (Finland), and one country under cooperative agreement (Canada). The agency is headquartered in Paris, France.
EUS
Equipment Unique Stowage
Eustachian tube
The eustachian tube is a tube, lined with mucous membrane, that joins the nasopharynx and the middle ear, allowing equalization of the air pressure in the middle ear with atmospheric pressure.
EUV
Extreme Ultraviolet
Evacuate
Evacuate means to empty or remove the contents.
EVAL
Earth-Viewing Application Laboratory
EVAS
Extravehicular Activity System
EVS
Equipment Visibility System
EVT
Experiment Verification Test
EX
Experimenter
EX
Explosive
Exam
Examination
EXC
Experiment Computer
EXCB
Experiment Connector Bracket
Excitability
In neurophysiology, excitability refers to the triggering of a conducted impulse in the membrane of a muscle cell or nerve fiber. During excitation, a polarized membrane becomes momentarily depolarized and an action potential is set up.
Excreta
Excreta is waste matter eliminated or separated from an organism.
Excretion
Excretion is the transport and expulsion of waste products such as urine or carbon dioxide. It also refers to the release of hormones or protein products from cells or tissues.
Excretory
Excretory describes the act or process of eliminating metabolic waste products from the body.
Exercise capacity
Exercise capacity is the maximum ability of the body to take up and use oxygen to do work. This is often reported as the maximum number of liters of oxygen that the body can use in a minute.
Exocrine
Exocrine glands discharge secretions by means of a duct, which opens onto an epithelial surface (a tissue that covers the external surface of the body and lines hollow structures inside the body).
EXP
Experiment
Expired gas pressure
Expired gas pressure is positive pressure in the alveoli (air sacs) of the lungs. This positive pressure allows air to be exhaled.
Extended Duration Orbiter Medical Project (EDOMP)
The Extended Duration Orbiter Medical Project (EDOMP) was conducted from 1989 to 1996 to address concerns about the physiologic condition of Shuttle astronauts on missions up to 16 days in duration. Before this project began, the Shuttle had not flown longer than 10 days. Space travelers may faint when they stand up (orthostatic intolerance) after all but the shortest flights, and their muscle strength may be reduced. The program focused on ensuring that the crew could land the Orbiter and exit from it without help after a 16-day flight. Astronauts on 40 Shuttle flights (STS-32 through STS-72) participated in 36 EDOMP investigations. The results of these investigations were used to make rules and recommendations for 16-day flights. Several types of exercise devices (i.e. a treadmill, a cycle ergometer, and a rower) were among the devices and procedures developed to prevent the deconditioning of the body that occurs during space flight. The crew transport vehicles, in which astronauts are now transported after landing, were built to enhance medical capabilities at the landing site as well as crew comfort and safety. A database, 125 formal publications, and 299 abstracts, technical papers, and presentations have also resulted from the EDOMP.
Extensor
An extensor is a type of muscle which works to straighten a limb, the antagonist of a flexor.
Extensor Digitorum Longus
The extensor digitorum longus is a superficial muscle of the lower leg which allows one to extend the foot.
Extracellular fluid
Extracellular fluid is the fluid which is inside the body, but outside the cells that are within the body.
Extracellular fluid volume
Extracellular fluid volume is the volume of the fluid external to the body's cells.
Extravehicular Activity (EVA)
An extravehicular activity, or EVA, is any activity that occurs external to the spacecraft requiring the crewmember to wear a life support suit.
Exudative
Exudative refers to a substance that may ooze or pass gradually out of a body structure or tissue. Specifically, this refers to a fluid or semisolid which may become encrusted or infected because of injury or inflammation.
Eye grounds
The eye grounds is the fundus of the eye, the fundus being the base or the deepest part of an organ or the portion farthest from the mouth of an organ.
F
Fahrenheit Degrees
F
Formatted
F
Forward End Cone
FAA
Federal Aviation Administration
Fab
Fabrication
Fac
Facility
FACI
First Article Configuration Inspection
Factor D
Factor D is an enzyme important in the activation of the complement system. This complicated system of enzymes protects humans by killing microorganisms and infected cells.
FAME
Franco-American Macaque Experiment
FAO
Flight Activity Officer
FAR
Flight Acceptance Review
FAS
Federation of American Societies
FASEB
Federation of American Societies for Experimental Biology
Fast myosin
Myosin is the most abundant protein in muscle fibrils, having the important properties of elasticity and contractility. Together with another protein called actin, it comprises the principal element which allows muscles to contract. Fast myosin refers to myosin found in fast-twitch muscle fibers, which are adapted for very rapid and very powerful muscle contractions, such as for jumping or for short-distance powerful running.
Fast-twitch
Fast-twitch describes a muscle fiber that contracts quickly, especially during brief high-intensity physical activity requiring strength.
Fast-twitch fiber
A fast-twitch fiber is a muscle fiber that produces force for rapid movement and exercise, such as for jumping or full-speed running for a short distance. These fibers use no oxygen for energy, thus are called anaerobic.
Fast-twitch muscle fiber
Fast muscle fibers have much larger fibers than slow muscle fibers for greater strength of contraction; they are adapted for very rapid and very powerful muscle contractions, such as for jumping or for short-distance powerful running.
Fatigability
Fatigability is a measure of the rate at which fatigue is induced.
Fatigue
Fatigue means mental or physical tiredness, usually caused by prolonged or intense activity, but also possibly caused by disease, lack of adequate nutrition or other anomalous factors.
Fatigue Test
A fatigue test is a test which determines how much work/activity can be accomplished by different muscles before their efficiency is reduced.
FATR
Flight Acceptance Test Review
FAUST
Far Ultraviolet Astronomy
FBC
Fill & Bleed Cart
FC
Flight Control
FCD
Flight Control Division
FCE
Flight Crew Equipment
FCOS
Flight Computer Operating System
FCR
Flight Control Room
FCT
Flight Control Team
FD
Facility Developer
FD
Flight Director
FD
Flight Day
FDD
Flight Definition Document
FDF
Flight Data File
FDM
Flight Data Manager
FDOR
Final Design and Operations Review
FDR
Final Design Review
FDS
Flight Design and Schedule
FE
Facilities Engineer
FED
Federal
FEDP
Facilities and Equipment Design Plan
FEDWG
Flight Experiment Data Working Group
FEE
Frog Embryology Experiment
FEL
First Element Launch
Femur
The femur, also called the thigh bone, is the long bone between the hip and the knee.
FEP
Fluorinated Ethylene Propylene
FEP
Front End Processor
FERD
Facility and Equipment Requirements Document
Ferment
In bacteriology, ferment means the anaerobic dissimilation of substrates with the production of energy and reduced compounds. The mechanism of fermentation does not involve a respiratory chain or cytochrome, hence oxygen is not the final electron acceptor as in oxidation.
Ferric
Ferric is iron with a valence of three.
Ferritin
Ferritin is an iron-protein complex and is one of the forms in which iron is stored in the tissues of the intestine, spleen, and liver.
Ferrous
Ferrous is iron with a valence of two.
FES
Fluids Experiment System
FEU
Frog Embryology Unit
FI
Flexible Input
Fibrinogen
Fibrinogen is a substance present in blood plasma that causes blood coagulation.
Ficoll-Hypaque technique
The Ficoll-Hypaque technique is a density gradient centrifugation test for separating lymphocytes from other formed elements in blood; the sample is layered onto a Ficoll-sodium metrizoate gradient of specific density; following centrifugation, lymphocytes are collected from the plasma-Ficoll interface.
Fiducial
Fiducial means regarded or employed as a standard of reference
FIFO
First In First Out
Filamentous
Filamentous means composed of filaments or threadlike structures.
FILO
First In Last Out
Finger cot
A finger cot is a latex sheath for the finger.
Finger pulse volume
Finger pulse volume is a measure of variations in the size of the finger resulting from changes in the amount of blood present.
Firing frequency
Firing frequency is the rate (or frequency) of the excitation of nerve or muscle fibers (called firing).
Fissure
A fissure is a crack-like lesion or wound of the skin.
Fixative
A fixative is a chemical which renders a cell or organism suspended or preserved in a stable state, usually so that it can be studied at a later date. For instance, a fixative might be used to preserve a tiny organism on a microscope slide.
Fixed
The term "fixed" refers to a chemical treatment of tissue or cells that results in preservation.
FL
Flammable Liquid
Flammability
Flammability is the ability of a substance to have a combustion reaction; often determined flash point which is the lowest temperature at which a substance will ignite when exposed to a flame.
FLAP
Flight Application Software Packages
FLAP
Spacelab Flight Application Software
Flash frozen
Flash frozen means the process of freezing multiple solutions with liquid nitrogen to prevent diffusion between them until they are allowed to thaw.
Flatulence
Flatulence is the presence of an excessive amount of air or gas in the stomach and intestinal tract, causing distension of the organs and in some cases, mild to moderate pain.
Flavobacterium
Flavobacterium is a genus of aerobic to facultatively anaerobic, nonsporeforming, motile and nonmotile bacteria (family Achromobacteraceae) containing Gram-negative rods; motile cells are peritrichous. These organisms characteristically produce yellow, orange, red, or yellow-brown pigments. They are found in soil and fresh and salt water. Some species are pathogenic.
FLEX IN
Flexible Input
Flexor
A flexor is a type of muscle which works to flex a limb (or bend towards the body); and is the opposite of an extensor, which pulls a limb away from the body.
Flora
Flora are microorganisms that live on or within a body to compete with disease-producing microorganisms and provide a natural immunity against certain infections.
Floral initiation
Floral initiation is the first stage of flower production.
Floret
A floret is a small flower or cluster of flower buds, such as in a head of cauliflower.
Flow cytometer
A flow cytometer is a device used to perform flow cytometry. Flow cytometry is a method of measuring fluorescence from stained cells that are in suspension and flowing one at a time through the point of focus of one or two lasers, which activate the dyes. Flow cytometry is used to measure cell size, number, viability and nucleic acid content with the aid of acridine orange, Kasten's fluorescent Feulgen stain, ethidium bromide, trypan blue and other selective staining agents.
Flow cytometry
Flow cytometry is a method used to count cells (especially blood cells), using a glass chamber of known volume.
FLT
Flight
Fludrocortisone
Fludrocortisone is a synthetic steroid medication used in replacement therapy when a patient's adrenal cortex does not produce normal amounts of hormones.
Fluence
Fluence refers to the ease with which particles flow.
Fluid balance
Fluid balance is the relationship between fluid intake and fluid output. A negative fluid balance indicates that more fluid was put out than taken in during a given time period; a positive fluid balance indicates the opposite.
Fluid loading
Fluid loading is the ingestion of unusually large amounts of fluid, usually with the intention of increasing plasma volume.
Fluid physics
Fluid physics is the science of phenomena observed in fluids, and the behavior of fluids in different conditions. For example, thermic convection influences the behavior of fluids. In microgravity, thermic convection does not exist and other phenomena such as Marangoni convection (which is overlayed by thermic convection on Earth) can be observed and studied.
Fluid shift
Fluid shift refers to the shift of fluids from the lower to the upper body upon exposure to or recovery from microgravity. This phenomenon also occurs to a lesser extent during bed rest or exposure to lower body negative pressure. It may also refer to fluid transfer between intracellular and extracellular compartments.
Fluorescence microscopy
Fluorescence microscopy is the use of a light microscope that uses fluorescent light to analyze specimens.
Fluorescent bone marker
A fluorescent bone marker is a chemical marker that binds to cell constituents. Its presence is noted microscopically by the emitted fluorescence when certain types of light traverse the thin section of tissue.
Fluorometric
A fluorometer is an instrument used to measure the intensity of radiation.
Flux
Flux can be defined as a continuous movement, or the rate of flow of particles or energy. It also refers to a quantity expressing the strength of a force field in a given area.
FM
Frequency Modulation
FMEA
Failure Mode Effects Analysis
FMECA
Failure Mode Effects and Criticality Analysis
FMR
Ferromagnetic Resonance
FMR
Finance Management Report
FMS
Fluid Management System
FO
Functional Objective
FOB
Freight on Board
FOC
Full Operational Capability
FOD
Flight Operations Directorate
Folic acid
Folic acid is a yellow, crystalline, water-soluble vitamin of the B compex group essential for cell growth and reproduction.
Fomite
Fomite is a non-living material, such as bed linen, which may convey pathogenic organisms.
FOR
Final Operations Review
Force
A force is the manifestation of the action of one body upon another. Forces arise from the action of two bodies in contact with one another.
Force transducer
A force transducer is a device that converts force to another form of energy, such as an electical signal.
Forced Expiratory Flow
Forced expiratory flow is measured by a simple pulmonary test; in performing the test the person first takes as deep a breath as possible, then exhales as rapidly and as completely as possible into a machine known as a spirometer, which measures the amount of air inhaled or exhaled.
Forced Expiratory Volume
The forced expiratory volume is the volume of air resulting from the forced expiratory flow test in which a person first inspires maximally to the total lung capacity, then exhales as rapidly and as completely as possible.
Forced Vital Capacity (FVC)
Forced Vital Capacity (FVC) is the volume of air resulting from the forced expiratory flow test in which a person first inspires maximally to the total lung capacity, then exhales as rapidly and as completely as possible.
Forcing function
A forcing function is used to excite a system so that the systems responses can be measured.
Formaldehyde
Formaldehyde is a pungent gas; in liquid form, it is used as an antiseptic, disinfectant and fixative for tissues.
Formalin
Formalin is a 37% aqueous solution of formaldehyde, used as a histologic fixative.
FOS
Flight Operations Support (Personnel)
Fourier analysis
Fourier analysis is a method of converting a function of time or space into a function of frequency; it is used in the reconstruction of images derived from computed tomography and magnetic resonance imaging in radiology and in analysis of any kind of signal for its frequency content.
FOV
Field of View
Fovea
The fovea is the part of the retina in which vision is sharpest. It is a slight depression or pit at the back of the retina near the optic nerve.
FPI
Flight Payloads Integration
FPM
Flight Project Manager
FPM
Fluid Physics Module
FPS
Flight Propulsion System
fps
Feet per Second
FPV
Flow Proportioning Value
FR
Failure Report
FR
Frame
FR
Functional Requirements
Fractionation
Fractionation means to separate components of a mixture.
Frame of reference
A frame of reference is used by the Central Nervous System of humans and most animals to orient the body in different situations. The reference for the vestibular organ is the gravitational force, which pulls everything on Earth downwards (to the center of the Earth) with the force of 1g.
FRB
Failure Review Board
FRD
Failure Requirements Document
FRD
Functional Requirements Document
Freons
Freons are a group of halogenated hydrocarbons, usually based on methane, containing one or more fluorine and/or other halogen atoms. Freons are commonly used as refrigerants and propellants for aerosols.
Frequency
Frequency is the number of times a phenomenon occurs within a specified interval such as the number of repetitions per unit time of a complete waveform.
FRR
Flight Readiness Review
FRVR
Flight Readiness Verification Review
FS
Factor of Safety
FS
Frequency Scatterometer
FS
Flammable Solid
FSCM
Federal Supply Code for Manufacturers
FSE
Flight Support Equipment
FSK
Frequency Shift Keyed
FSN
Federal Stock Number
FSO
Functional Supplemental Objective
FSP
Flight Support Plan
FSS
Fire Suppression System
FSS
Flight Support Structure
FSSR
Functional Subsystem Software Requirements
FST
Flight Support Team
FST
Functional System Test
ft
Foot
FTMS
Fluid Transfer Management System
FTS
Federal Telecommunications System
FTS
Flight Telerobotic Servicer
FUNC
Functional
Functional residual capacity
The functional residual capacity is the amount of air remaining in the lungs at the end of normal expiration (about 2300 ml).
Fungi
Fungi are any of a large group of plants which do not contain chlorophyll, including the yeasts, molds, and mushrooms.
FUO
Follow-up Output
Furunculosis
Furunculosis is a condition marked by the presence of localized pyogenic infection originating in the hair follicle.
FUSE
Far Ultraviolet Spectroscopy Explorer
Fusobacterium
Fusobacterium is a genus of bacteria (family Bacteroidaceae) containing Gram-negative, nonsporeforming, obligately anaerobic rods, which produce butyric acid as a major metabolic product. Fusobacteria may be nonmotile or motile. Motile cells are peritrichous. These organisms are found in the cavities of man and other animals; some species are pathogenic
FVT
Flight Verification Test
FW
Fiscal Week
FWD
Forward
FWHM
Full Width, Half Maximum
FWSS
Flight Waste Stowage System
FWW
Food, Water and Waste Management
FY
Fiscal Year
FY 80
Fiscal Year 1980
g
Acceleration of Gravity
g
Grams
G
Ground-Shield Pin Number
G&A
General and Administrative
G-A
Ground-to-Air
G-jitter
G-jitter is fluctuation in acceleration forces acting on a spacecraft in orbit.
G-suit
A G-suit is a garment worn by space travelers during launch and/or landing. It exerts pressure, usually by means of inflatable air bladders, on the thighs and abdomen to lessen the pooling of blood in the lower part of the body during acceleration.
GaAs
Gallium Arsenide
Gait
Gait is a manner of walking.
Galactic cosmic rays
Galactic cosmic rays are the highest energy charged particle radiation to reach Earth. They originate from sources outside the the solar system and are distributed throughout the Milky Way galaxy. They travel at nearly the speed of light striking Earth from all directions.
Galactic radiation
Galactic radiation is energetic particles from distant stars and galaxies.
Galley
A galley is the kitchen of a ship or aircraft.
Galvanometer
A galvanometer is an instrument used to measure the intensity of an electric current, usually by the deflection of a magnetic needle.
Gamma radiation
Gamma radiation is electromagnetic radiation of shorter wavelength and higher energy than X-rays. Gamma rays have greater penetration than X-rays and are harmful to living tissues. Carefully controlled doses are used in radiotherapy.
Gamma ray
A gamma ray is a photon emitted spontaneously by a radioactive substance.
Gamma-aminobutyric acid (GABA)
Gamma-aminobutyric acid (GABA) is an acid found in the central nervous system -- predominantly in the brain -- where it acts as an inhibitor of nerve impulses.
GAMS
Gas Analysis Measuring System
Ganglia
Ganglia are any structures containing a collection of nerve cell bodies.
Ganglion
A ganglion is any structure containing a collection of nerve cell bodies in the central or peripheral nervous system.
Gargle
Gargle means to rinse the space between the cavity of the mouth and the pharynx by taking fluid in the mouth and forcing the expired breath through it while the head is held far back. Gargle can also mean a medicated fluid used wash the throat.
GAS
Gas Analyzer Spectrometer
GAS
Get Away Special
GAS
Ground Application Software
Gas chromatography
Gas chromatography is the process of separation and analysis of different substances according to their different attraction to a standard absorbent substance.
Gas exchange
Gas exchange is the exchange of carbon dioxide for oxygen.
Gas exchange ratio
The gas exchange ratio (respiratory exchange ratio, R) is the ratio of carbon dioxide output to oxygen intake. The value changes under different metabolic conditions, but the average value is considered to be 0.825.
Gas liquid chromatography (GLC)
Gas liquid chromatography utilizes the same method of separation as gas chromatography, except the stationary phase is liquid rather than solid.
Gastric acid
Gastric acid is the liquid secreted by the gastric glands of the stomach; its main digestive constituents are hydrochloric acid, mucin, renin and pepsinogen. The acid acts to aid in digesting food and killing unwanted bacteria and organisms that have been ingested with food.
Gastric emptying
Gastric emptying is emptying of the stomach into the small intestine for the next step in digestion.
Gastrocnemius
The gastrocnemius is a muscle that forms the greater part of the calf of the leg; it flexes the knee and foot so that the toes point downward.
Gastrocnemius medialis
The gastrocnemius medialis is the section of the gastrocnemius muscle that forms the greater part of the calf of the leg.
Gastrocnemius soleus
The gastrocnemius soleus are the major muscles of the calf.
Gastroenteritis
Gastroenteritis is the inflammation of the mucous membranes that line the stomach and intestine.
Gastrointestinal
Gastrointestinal refers to the stomach and intestines.
Gastrointestinal motility
Gastrointestinal motility is the contraction of the smooth muscle layers of the gastrointestinal tract to move food through the tract during digestion.
Gastrointestinal physiology
Gastrointestional physiology is the study of the function of the stomach and intestines.
Gauer-Henry reflex
The Gauer-Henry reflex can be described as follows: the headward shift of fluids seen in space flight is thought to produce a transient increase in central blood volume; the transient increase is detected by stretch receptors in the heart and interpreted as an increase in total blood volume. A compensatory loss of water and sodium is then thought to be effected by a series of neural, humoral and direct hydraulic mechanisms.
Gavage
Gavage is a type of exposure in which a substance is administered to an animal (or human) through a stomach tube.
Gaze
Gaze is the act of looking steadily at an object.
GB
Gigabyte
GB
Ground Based
GBDS
Ground Based Development System
GBT
Ground Based Test
GCC
Ground Cooling Cart
GCMA
Gas Control Measuring System
GCOS
Ground Computer Operating System
GD
General Dynamics
GDMS
Ground Data Management System
GDP
Generalized Document Processor
GDP Mannose Mannosyl Hydrolase
GDP Mannose Mannosyl Hydrolase is the protein responsible for the incorporation of carbohydrates into bacterial cell walls. Understanding its structure and function will help control entero-pathogenic bacteria which cause food poisoning.
GDS
Ground Data System
GDSD
Ground Data Systems Division
Gel electrophoresis
Gel electrophoresis is the process of separating a mixture of molecules in a gel media by the application of an electric field. In general, molecules with similar electric charges and density will migrate at the same rate together in the gel.
GEMS
The Gas Exchange Measurement System,or GEMS, is a unit consisting of two Gas Analyzer Systems that measures the CO2 and H2O vapor going into and leaving the leaf chamber.
Gene
The gene is the functional unit of heredity which occupies a specific place on a chromosome.
Gene expression
Gene expression refers to the transcription and translation of a specific part of the DNA code with the ultimate outcome being protein synthesis.
Gene regulation
Gene regulation is the control of gene transcription by chemical factors that regulate the RNA polymerase binding to DNA.
Gene transcription
Gene transcription is the process of constructing a messenger RNA molecule using a DNA molecule as a template, with resulting transfer of genetic information to the messenger RNA.
Genera
Genera is a subdivision of a family of animals, plants or microorganisms. A genus (plural) is usually composed of several closely related species, but the genus Homo has only one species, humans (Homo sapiens).
Genetic
Genetic refers to genetics, which is a branch of science concerned with heredity.
Genetic program
The genetic program, also called the genetic code, is the information carried by the genes (DNA and RNA) and determines how an organism develops, including its appearance, function, and instincts.
Genomic
Genomic means relating to the genome, the genetic material of an organism.
GEO
Geosynchronous Earth Orbit
Geomagnetic
Geomagnetic means pertaining to the earth's magnetic field.
Geophysics
Geophysics is the study of Earth physics including the fields of meteorology, hydrology, oceanography, seismology, volcanology, magnetism, radioactivity and geodesy.
Geosynchronous refers to a special type of orbit around the Earth, where an object orbits the Earth in the same direction and at the same speed as the Earth's own rotation. This results in the orbiting object remaining in a fixed position above a geographic point on the surface of the Earth. Telecommunications satellites are often put into geosynchronous orbit so that they may be accessible via radio waves from one area of Earth at all times.
Geotrichum candidum
Geotrichum candidum is a fungus that may cause lesions in the pulmonary and alimentary tracts of humans; however, these lesions may be secondary to an underlying unrelated condition.
German Aerospace Research Establishment (DLR, DFVL
German Aerospace Research Establishment (DFVLR-Deutsche Forschungsanstalt fur Luft- und Raumfahrt) is responsible for basic research in the German space program, as well as management, operations and general support of all German sponsored space activities. DFVLR was renamed DLR in 1989. The agency is headquartered in Cologne, with other centers in Berlin, Göttingen Braunschweig, Stuttgart, Oberpfaffenhofen (Munich).
Germination
Germination is the process of beginning to grow or develop.
Giddy means having a reeling, lightheaded sensation; dizzy.
Giemsa chromosome banding (G-banding)
Giemsa chromosome banding (G-banding) is a unique chromosome staining technique used in human cytogenetics to identify individual chromosomes, which produces characteristic bands.
Giemsa staining
Giemsa staining is a unique chromosome staining technique used to identify individual chromosomes, in which characteristic bands are produced. It is also known as G-banding.
Gingival
Gingival means relating to the gums.
Gingival sulcus
Gingival sulcus, also called the gingival crevice, is the space between the surface of the tooth and the free gingiva, or gum.
GIRD
Ground Integration Requirements Document
Girth
Girth is the distance around an object; circumference.
Glia
Glia refers to glial cells or neuroglia, the special connective tissue of the central nervous system.
Glial
Glial refers to glia or neuroglia, the special connective tissue of the central nervous system.
Globus pallidus
The globus pallidus is a structure in the brain involved in the regulation of voluntary movements at a subconscious level.
Glomerular Filtration Rate (GFR)
The glomerular filtration rate (GFR) is the amount of glomerular filtrate (a substance which is the same as plasma except that it has no significant amount of proteins) that is formed each minute in all nephrons of both kidneys. The GFR is normally about 125 ml/minute.
Glovebox
A glovebox is a device used to isolate an area for work with potentially hazardous substances or materials that need to be free from direct contact with the outside environment for any reason. Most gloveboxes used during flight are small, tightly enclosed boxes with a glass panel for viewing and special airtight gloves that a person on the outside can use to manipulate objects inside.
Glucocorticoid
A glucocorticoid is a steroid hormone that predominantly affects the metabolism of carbohydrates and, to a lesser extent, fats and proteins. Glucocorticoids are made in the outside portion (the cortex) of the adrenal gland. Cortisol is the major natural glucocorticoid. The term glucocorticoid also applies to equivalent hormones synthesized in the laboratory.
Glucose
Glucose is a simple sugar found in certain foods, especially fruit, and is a major source of energy occurring in human and animal body fluids. The determination of blood glucose levels is an important diagnostic test in diabetes and other disorders.
Glucose-6-phosphate dehydrogenase
Glucose-6-phosphate dehydrogenase is an enzyme which participates in the formation of glucose from carbon dioxide as part of the process of photosynthesis.
Glutamate
Glutamate is a derivative of glutamic acid, an amino acid occurring in proteins.
Glutaminase
Glutaminase is an enzyme found in the kidney that catalyzes the breakdown of the amino acid glutamine to ammonia and glutamic acid. This breakdown is a stage in the production of urea, a major component of urine.
Glutaraldehyde
Glutaraldehyde is a compound used as a fixative for localization of enzyme activity; tissues fixed in glutaraldehyde may be stored for weeks or months before processing.
Glutathione (GTH)
Glutathione (GTH) is a tri-peptide composed of three amino acids: cysteine, glutamic acid and glycine. Glutathione and the enzymes it forms, such as GTH peroxidase, are essential to all life and are found in tissues of virtually all plants and animals. GTH is present in all human cells, with the highest levels found in the liver, the lenses of the eyes, pancreas, spleen and kidneys.
Glyceraldehyde phosphate dehydrogenase
Glyceraldehyde phosphate dehydrogenase is an enzyme found in cells that participates in the glucose metabolism by removing a hydrogen atom from glyceraldehyde phosphate, a glucose metabolite, and adding a phosphate group to form 1,3 bisphosphoglycerate.
Glycine
Glycine is an amino acid constituent of proteins in the human body.
Glycogen
Glycogen is a large, complex carbohydrate molecule produced from glucose in the liver and muscles when blood sugar levels are high. Glycogen is broken down into lactic acid when it is used as an energy source in the liver or muscles.
Glycolysis
Glycolysis is the process of transforming glucose into lactic acid in the muscles (or other tissues), for energy production when sufficient oxygen is not available in an emergency situation.
Glycolysis rate
Glycolysis rate is the rate of energy-yeilding conversion of D-glucose to lactic acid in various tissues, notably muscle, when sufficient oxygen is not available for respiration. Because molecular oxygen is not consumed in the process, it is frequently referred to as anaerobic glycolysis.
Glycolytic enzymes
Glycolytic enzymes are a part of the glycolytic pathway that act as a catalyst. They work in sequence to convert glucose to pyruvate which produces adenosine triphosphate (ATP), the energy carrier.
Glycosaminoglycan (GAG)
Glycosaminoglycan (GAG) is the polysaccharide unit that makes up proteoglycans, a molecule made of saccharides and proteins. GAGs are extracellular matrix molecules that help give tissues like cartilage their rigid structure.
Glycoside
Glycoside is any of several carbohydrates that yield a sugar and a non-sugar on hydrolysis. The plant digitalis purpurea yields a glycoside used in the treatment of heart disease.
gm
Gram
GML
General Measurement Loop
GMP
Guanosine 5'-monophosphate (guanylic acid)
GMS
General Management System
GMT
Greenwich Mean Time
GN&C
Guidance, Navigation and Control
GN2
Gaseous Nitrogen
GN2 freezer
A GN2 freezer is a small storage canister which uses gaseous nitrogen to keep samples at or below freezing.
GND
Ground
GNP
Gross National Product
GO2
Gaseous Oxygen
GOAL
Ground Operations Aerospace Language
Golgi
The Golgi apparatus is a collection of vesicles and folded membranes in a cell, usually connected to the endoplasmic reticulum. It stores and later transports the proteins manufactured in the endoplasmic reticulum. Golgi cells are types of neurons (nerve cells) within the central nervous system.
GOR
Ground Operations Review
GOS
Ground Operating System
GOWG
Ground Operations Working Group
GPC
General Purpose Computer
GPGU
General Plant (Growth) Unit
GPM
Gallons per Minute
GPO
Government Printing Office
GPPF
Gravitational Plant Physiology Facility
GPS
Global Positioning System
GPTU
General Purpose Transfer Unit
GPWS
General Purpose Work Station
GR
Growth
Grab Air Sampler
The Grab Air Sampler is a device which used to collect air samples. The device is evacuated thus causing air to be quickly sucked into the device once the valve is opened.
Grab Sample Container (GSC)
The Grab Sample Container (GSC) is a device used to collect air samples. The device is evacuated thus causing air to be quickly sucked into the device as the valve is opened.
Gram-negative
Gram-negative denotes a bacteria that stains pink when stained with Gram’s stain. This staining technique is useful in bacterial taxonomy and identification and to indicate fundamental differences in cell wall structure.
Gram-positive
Gram-positive denotes a bacteria that stains purple-black when stained with Gram’s crystal violet stain, usually indicating that the outer structure of the bacterium consists of a cytoplasmic membrane surrounded by a thick, rigid bacterial cell wall comprised of peptidoglycan. This staining technique is useful in bacterial taxonomy and identification, and to indicate fundamental differences in cell wall structure.
Gram’s stain
Gram’s stain is a method to differentially stain bacteria. Bacterial smears are fixed by flaming, stained in a solution of crystal violet, treated with iodine solution, rinsed, decolorized and then counterstained with safranin. Microorganisms are classified as either Gram-positive or Gram-negative.
Granulocyte
A granulocyte is a leukocyte, or white blood cell, characterized by the presence of cytoplasmic granules.
Granulocyte Colony Stimulating Factor
Granulocyte Colony Stimulating Factor is an immunoprotein produced by leukocytes during inflammation which functions to increase the proliferation of granulocytes in the bone marrow.
Granulocytosis
Granulocytosis is an increase in the total number of granulocytes, a type of leukocyte, in the blood.
Graviperception
Graviperception is the sense that gives knowledge of body position, equilibrium, direction of gravitational forces, and the sensation of "down" or "up." This perception in humans is provided by highly specialized receptor organs and nerve endings in the inner ear, joints, tendons and muscles that give the brain information about body position. Other organisms, like plants, also possess graviperception.
Gravireceptors
Gravireceptors are highly specialized receptor organs and nerve endings in the inner ear, joints, tendons and muscles, that give the brain information about body position, equilibrium, direction of gravitational forces, and the sensation of "up" or "down."
Gravisensitivity
Gravisensitivity is the sense of body position, equilibrium, direction of gravitational forces, and the sensation of "down" or "up." This sense in humans is provided by highly specialized receptor organs and nerve endings in the inner ear, joints, tendons and muscles that give the brain information about body position. Other organisms, like plants, also possess gravisensitivity.
Gravitational field
The gravitational field of the Earth is what pulls everything towards the center of our planet. Its force is defined as 1g (one "g" or one gravity). In comparison, the gravitational force present on the moon is 0.6 g’s, this weaker force allowed the astronauts to do their famous moon-jumps.
Gravitational loading
Gravitational loading refers to the application of force to a bone or part of the body. Under normal circumstances on Earth, gravity "loads" the bones and muscles with the force required to support the body.
Gravitoinertial environment
A gravitoinertial environment is an environment in which gravity and inertia exist.
Gravity gradient
A gravity gradient is a change in the gravitational force depending on the relative position to the Earth.
Gravity receptors
Gravity receptors, also known as gravireceptors, are highly specialized receptor organs and nerve endings in the inner ear, joints, tendons and muscles, that give the brain information about body position, equilibrium, direction of gravitational forces, and the sensation of "down" or "up."
GRD
Ground
GRMS
Acceleration Root Mean Square
GRO
Gamma Ray Observatory
Growth Hormone (GH)
Growth Hormone (GH), also called somatotropin, is a protein hormone of the anterior lobe of the pituitary. It is produced by the acidophil cells and it promotes body growth, fat mobilization, and inhibition of glucose utilization. It is diabetogenic when present in excess.
Growth medium
A growth medium contains nutrients and is a substance on or in which microorganisms or cells can be grown.
GSA
General Services Administration
GSE
Ground Support Equipment
GSFC
Goddard Space Flight Center
GSI
Government Source Inspection
GTOD
Greenwich True On Date
Guanylyl cyclase
Guanylyl cyclase is an enzyme that catalyzes the synthesis of cyclic guanosine 3',5'-monophosphate (cGMP), a cyclic nucleotide that participates in intracellular signaling, from the substrate guanosine 5-triphosphate (GTP). There are two major classes of this enzyme, a soluble form and a transmembrane form. The catalytic activity of the soluble form is activated by the free radical nitric oxide (NO) when it complexes with the heme cofactor of the enzyme.
Gut wall
Gut wall refers to the wall of the intestine. It is here that most of the absorption of food from the digestive track into the body takes place.
GVPRD
Ground Verification Plan and Requirements Document
Gyroscope
A gyroscope is a rotating wheel, mounted in a ring or rings, for illustrating the dynamics of rotating bodies, the composition of rotations, etc. It can also be a form of the above apparatus, mounted so delicately as to render visible the rotation of the earth, through the tendency of the rotating wheel to preserve a constant plane of rotation, independently of the earth's motion.
H
Height
H/L
Hangar L
H/W
Hardware
H/X
Heat Exchanger
Hab
Habitation
Habitability
Habitability describes the capacity of a specific environment to maintain a certain quality of life. This term is often applied to the living resources and conditions of space vehicles.
Hair cell
Hair cells are sensory cells that react to mechanical stimuli and transmit information to the brain; they are the basic sensory unit of the inner ear.
HAL
Houston Aeronautic Language
HAL-S
Houston Aerospace Language Shuttle
HALOE
Halogen Occultation Experiment
Hamstring
A hamstring is any of the tendons at the back of the thigh; they attach the five hamstring muscles to their insertions on the bones of the lower leg.
Hand Grip Dynamometer (HGD)
The Hand Grip Dynamometer (HGD) is a device that measures the performance of the wrist flexor muscles. The subject has to actively push against a plate, thereby bending the wrist. At the same time, sensors inside the HGD measure the force applied.
Haptic
Haptic means referring to the sense of touch.
Haptoglobin
Haptoglobin is a protein present in blood serum that combines with hemoglobin to form a complex that is rapidly removed from the circulation by the liver.
Harvard step test
The Harvard step test is a type of cardiovascular endurance test that measures the ability to exercise continuously for extended periods without tiring. The subject steps up and down on a platform at a rate of 30 steps per minute for 5 minutes or until exhaustion. Exhaustion is the point at which the subject cannot maintain the stepping rate for 15 seconds. The subject immediately sits down on completion of the test, and the heart beats are counted after for 1 to 1.5, 2 to 2.5, and 3 to 3.5 minutes.
Harvest
Harvest means to gather (at maturity).
Harvestmen
Harvestmen are arachnids that resemble spiders but have a small rounded body and very long slender legs; also called “daddy longlegs."
HBC
Hyperbaric Chamber
HBR
High Bit Rate
HCG
Human Chorionic Gonadotropin
HDBK
Handbook
HDFDB
Hardware Development Facility Data Base
HDP1
Hardware Development Plan
HDRR
High Data Rate Recorder
He
Helium
Head-down tilt
Head down tilt is a laboratory procedure wherein a subject lies flat on his back on a tilted table so that the head is below the feet; it is used to cause a headward fluid shift. Prolonged bed rest with a slight head down tilt (usually with a 5-6 degree tilt from the horizontal) can reproduce some of the effects caused by exposure to microgravity.
Head-down tilt bed rest
Head-down-tilt bed rest is prolonged bed rest with a slight head-down-tilt (usually a 5-6 degree tilt from the horizontal). During head-down-tilt, the subject lies flat on his back on a tilted table so that the head rests below the feet, causing a headward fluid shift similar to the effect caused by exposure to microgravity.
Heart period
The heart period is the duration of one heart beat, also measured as the time between two heart contractions.
Heart rate
Heart rate is the number of heart beats per unit time, usually expressed as beats per minute.
Heat sink
A heat sink is a device which absorbs or removes heat from a thermal system.
Heavy ion
A heavy ion is an ion with mass greater than the normal mass for that element; an ion of a heavy isotope.
Heavy ion radiation
Outside Earth’s atmosphere, radiation from heavy ions, such as iron, exists. This kind of radiation is potentially more harmful than any other kind of radiation.
HED
High-Energy Deposition
HEFLEX
Helianthus Flight Experiment
HeG
Helium Glow
Helper T-cells
Helper T-cells are a type of white blood cell that contribute to (“help” with) the activation of the B-lymphocytes in the immunological process, thus helping to rid the body of foreign antigens.
Hematocrit
Hematocrit is the percentage of the volume of a blood sample occupied by cells, as determined by a centrifuge or device which separates the cells and other particulate elements of the blood from the plasma. The remaining fraction of the blood sample is called plasmocrit (blood plasma volume).
Hematologic
Hematologic means of or relating to hematology.
Hematological
Hematological means of or relating to blood or hematology.
Hematology
Hematology is the study of blood and blood forming tissues.
Hematopoiesis
Hematopoiesis is the formation of blood cells.
Heme
Heme is a subunit of the hemoglobin molecule that consists of an organic part and iron atom. The organic part is made up of four rings. The four rings are linked together to form a tetra structure. The iron atom is in the center of the four rings and binds to oxygen.
Hemin
Hemin is the chloride of heme in which the ferrous form of iron has become ferric (hematin is the hydroxide). Also termed hematin chloride; chlorohemin; ferriheme chloride; ferriprotoporphyrin; ferriporphyrin chloride; Teichman’s crystals; factor X for Haemophilus.
Hemoconcentration
Hemoconcentration is an increase in the proportion of red blood cells relative to the plasma, brought about by a decrease in the volume of plasma. Hemoconcentration may occur in any condition in which there is a severe loss of water from the body.
Hemocytometer
A hemocytometer is an apparatus used to estimate the number of blood cells in a quantitatively measured volume of blood.
Hemodilution
Hemodilution is an increase in plasma volume in relation to red blood cells; reduced concentration of red blood cells in the circulation.
Hemodynamic
Hemodynamic means of or relating to the physical dynamics of blood circulation.
Hemodynamics
Hemodynamics is the study of forces or mechanisms involved in blood circulation.
Hemoglobin
Hemoglobin is an iron-containing respiratory pigment contained within red blood cells; it gives the cells their red color. Hemoglobin, which has the unique property of combining reversibly with oxygen, picks up oxygen in the lungs and transports it to the rest of the body.
Hemoglobin-oxygen affinity
Hemoglobin-oxygen affinity reflects the binding strength or attraction of oxygen to hemoglobin.
Hemolysis
Hemolysis is the destruction of red blood cells with the release of hemoglobin into the surrounding fluid.
Hemolytic
Hemolytic refers to the destruction of red blood cells with the release of hemoglobin into the surrounding fluid.
Henry-Gauer response
The Henry-Gauer response is the inhibition of antidiuretic hormone secretion due to a rise in atrial pressure, which stimulates atrial stretch receptors.
HEPA
High Efficiency Particulate Air
Heparin
Heparin is a natural substance which inhibits blood clotting.
Heparinize
Heparinize means to treat with heparin to prevent clotting, as to heparinize blood.
Hepatic
Hepatic means relating to the liver.
Herpes simplex
Two types of herpes simples viruses exist: type 1 and type 2. Type 1 infections are marked by the eruption of one or more groups of vesicles on the vermilion border of the lips or at the external nares (fever blister or cold sore). Type 2 infections are characterized by such lesions on the genitalia. Both types commonly are recrudescent and reappear during other febrile illnesses or even physiologic states such as menstruation.
Herpesvirus
Herpesvirus is one of a group of DNA containing viruses causing latent infections in man and animals.
Herpetic
Herpetic means pertaining to, or of the nature of, herpes.
Heterotrophic plate count
Heterotrophic late count (HPC), formerly known as the standard plate count, is a procedure for estimating the number of live heterotrophic bacteria and measuring changes during water treatment and distribution in water or in swimming pools. Colonies may arise from pairs, chains, clusters, or single cells, all of which are included in the term "colony-forming units" (CFU).
Hexokinase (HK)
Hexokinase (HK) is an enzyme present in muscle and other tissues. It catalyzes the phosphorylation (adding a phosphor group) of glucose and other hexoses to form a hexose 6-phosphate.
HF
High Frequency
HFSS
High Frequency Sounder System
Hg
Mercury
HgCdTe
Mercury Cadmium Tellurium
HGD
The Hand Grip Dynamometer (HGD) is a device that measures the performance of the wrist flexor muscles. The subject has to actively push against a plate, thereby bending the wrist. At the same time, sensors inside the HGD measure the force applied.
HI-REL
High Reliability
High-LET particles
Linear energy transfer (LET) refers to the measurement of the number of ionizations which radiation causes per unit distance as it traverses the living cell or tissue. The concept involves lateral damage along the path, in contrast to path length or penetration capability. Medical X-rays and most natural background radiation are low LET radiation, while alpha particles have high LET.
High-performance liquid chromatography
High-performance liquid chromatography (HPLC) is the separation and detection of nonvolatile chemicals (i.e., chemicals with boiling points greater than 200 to250 degrees Celsius) in a mixture. A sample amount, typically 10 to 20 microliters of liquid, is injected onto the chromatographic column. The column is packed with the stationary phase, a material with very specific properties that permit it to absorb or adsorb specific components of the sample under certain conditions. The mobile phase is constantly flowing through the column. When the sample is injected, it is swept onto the column by the mobile phase. Since all chemicals are different, they will have different affinities (attractions) to both the stationary phase and the mobile phase; this is called partitioning. Some components of the mixture will have a strong attraction to the stationary phase and pass through the column very slowly, while others will have less of an attraction and therefore pass more quickly through the column. Parameters are optimized so that the compounds in the sample elute (exit the column) individually. When the compounds elute, they must be detected (measured). This is done using a detector that is appropriate to the chemicals being measured.
HIRD
Hangar-L Interface Requirements Document
HIRIS
High Resolution Imaging Spectrometer
Histochemical
Histochemical refers to the study of intracellular distribution of chemicals, reaction sites, and enzymes.
Histochemistry
Histochemistry is the study of the identification and distribution of chemical compounds within and between cells, by means of stains, indicators, and light and electron microscopy.
Histogram
A histogram is a form of statistical graph in which values are plotted in the form of rectangles on a chart; also known as a bar chart.
Histological
Histological refers to the science concerned the identification and distribution of chemical compounds within and between cells, by means of stains, indicators, and light and electron microscopy.
Histological examination
A histological examination is a method of studying the structure of tissues by means of special staining techniques combined with light and electron microscopy.
Histone octamer
Histones are the proteins associated with nucleic acids in the nuclei of plant and animal tissues. An octamer is an aggregate of eight particles attached together.
HIU
Hardware Interface Unit
HIV Capsid Protein
HIV Capsid Protein is a protein that makes up the outer shell, surrounding the genetic material, of the AIDS virus. This protein is a target for drugs that can fight the AIDS virus.
HKG
Housekeeping
HMF
Health Maintenance Facility
HMFDB
Health Maintenance Facility Data Base
HMMR
High Resolution Multifrequency Microwave Radiometer
Hoffman reflex (H-reflex)
The Hoffman reflex (H-reflex) is a spinal reflex that can be modulated by a nerve pathway from the otolith receptors.
HOL
High Order Language
Homeostasis
Homeostasis is the physiological process by which the internal systems of the body (e.g. blood pressure, body temperature, acid-base balance) are maintained at equilibrium despite variations in the external conditions.
Homeostatic
Homeostatic means relating to homeostasis, which is the physiological process by which the internal systems of the body (e.g. blood pressure, body temperature, acid-base balance) are maintained at equilibrium despite variations in the external conditions.
Horizontality
Horizontality means situated near the horizon.
Hormonal
Hormonal means of or relating to hormones.
Hormone
A hormone is a substance produced in one part of the body; it passes into the bloodstream and is carried to other distant organs or tissues where it acts to modify their structure or function.
HOSC
Huntsville Operations Support Center
Housing
Housing is the type of cage used to contain animals during space flight.
HP
High Pressure
HPA
High Power Amplifier
HPF
Hazardous Processing Facility
HPI
High Performance Insulation
HQ
Headquarters
HQTRS
Headquarters NASA
HR
Heart Rate
HR
High Rate
HR&T
Heat Rejection and Transport
HRDI
High Rate Demultiplexer Interface
HRDM
High Rate Demultiplexer
HRDW
Hardware
HRM
High Rate Multiplexer
HRMIS
High Rate Multiplexer Interface Simulator
HRMS
High Rate Multiplexer Simulator
HRP
Hardware Requirements Plan
HRPT
High Resolution Picture Transmission
hrs
Hours
HRSI
High Temperature Reusable Surface Insulation
HSAC
High Sensitivity Automatic Camera
HSO
Habitation/Station Operations
HST
Hubble Space Telescope
HTGPF
High Temperature General Purpose Furnace
HTM
High Throughout Mission
HTT
High Temperature Thermostat
Human factors
Human factors research is concerned with the interaction of humans with equipment, their environment, and each other to optimize the design of interactive workplaces for peak performance. In space flight, studying human factors has a special importance because of the time-critical interactions required between humans, machines and the environment.
Humerus
The humerus is the bone of the upper arm.
Humidity
Humidityis the amount of water vapor or moisture in the air.
Humoral
Humoral means circulating in the bloodstream.
Humoral immunity
Humoral immunity is the immediate response to an antigen which triggers antibody production. This is opposed to cell-mediated immunity, which involves white blood cells and is a delayed response to an antigen.
HVAC
Heating, Ventilating & Air Conditioning
HVC
High Voltage Converter
HW
Hardware
HX
Heat Exchanger
Hydration
Hydration is the chemical process in which water is taken into the body.
Hydrazine (N2H4)
Hydrazine is a chemical that, when mixed with an oxidizer, can be used as a monopropellant of satellites and the Space Shuttle once in orbit; it also fueled the first Titan rocket. Hydrazine derivatives are used in the manufacture of herbicides and fungicides, plant growth regulators, tranquilizers and tuberculosis drugs, and oxygen scavengers in boilers.
Hydrocarbon
A hydrocarbon is a compound containing only hydrogen and carbon.
Hydrogen
Hydrogen is a colorless, highly flammable gaseous element, the lightest of all gases and the most abundant element in the universe. As a component of water, hydrogen is crucial in the metabolic interaction of acids, bases, and salts within the body and in the fluid balance necessary for the body to survive.
Hydrology
Hydrology refers to the study of the distribution and circulation of water on land, in soil and rock and in the atmosphere.
Hydrostatic
Hydrostatic relates to the pressure of fluids or to their properties.
Hydrostatic gradient
A hydrostatic gradient is a change in the force, or pressure, of a fluid. The hydrostatic gradient in an adult standing upright and absolutely still is +90 mmHg between the veins of the feet and heart. This pressure difference is caused simply because of the weight of the blood in the veins between the heart and the feet.
Hydroxyapatite
Hydroxyapatite is the primary mineral component of bone. It has the chemical formula of 3Ca3(PO4)² and in crystal form is a hexagonal needle arranged in rosettes. It melts above 1100 degrees Celcius and cannot be dissolved in water.
Hydroxylysine
Hydroxylysine is one of the alpha amino acids.
Hydroxyproline
Hydroxyproline is a compound similar in structure to the amino acids and is found only in collagen.
Hygiene
Hygiene is the science or principles of health and the prevention of disease.
Hyper- and hypobaric physiology
Hyper- and hypobaric physiology is a discipline concerned with the study of ambient gases. Hyperbaric pertains to the pressure of ambient gases above 1 atmosphere, and hypobaric refers to the pressure of ambient gases below 1 atmosphere.
Hyperaldosteronism
Hyperaldosteronism is a disorder caused by overproduction of the adrenal hormone aldosterone, causing abnormalities in the sodium, water, and potassium levels in the body.
Hyperbolic
Hyperbolic describes a specific correlation/relationship of two variables to each other. When the first variable is zero, the second variable reaches its maximum; inversely, when the second variable is zero, the first variable is at its peak.
Hypercalcemia
Hypercalcemia is the presence of an abnormally high concentration of calcium in the blood.
Hypercalcinuria
Hypercalcinuria is the presence of an abnormally high concentration of calcium in the urine.
Hypercalciuria
Hypercalciuria is the presence of an abnormally high concentration of calcium in the urine.
Hypercalcuria
Hypercalcuria (or hypercalcinuria) is the presence of an abnormally high concentration of calcium in the urine.
Hypercapnic
Hypercapnic refers to the term hypercapnia, which describes an abnormally increased level of arterial carbon dioxide.
Hyperemic
Hyperemic refers to hyperemia, or the presence of an increased amount of blood in a body part or organ.
Hypergravity
Hypergravity means gravity forces higher than the "normal" Earth gravity.
Hyperosmolality
Hyperosmolality is the increased concentration of a solution expressed as osmoles of solute per kilogram of serum water.
Hyperosmotic
Hyperosmotic means having a concentration of osmotically active substances that is greater than the applicable standard.
Hyperoxaluria
Hyperoxaluria is an increased excretion of oxalate in the urine.
Hyperoxia
Hyperoxia is an increased concentration of oxygen in the tissues and organs.
Hyperoxic
Hyperoxic refers to an increased concentration of oxygen in the air or environment.
Hyperreflexia
Hyperreflexia is defined as lowering the response threshold consequent to electrical or mechanical stimuli applied at the muscle or the tendon, respectively. When the response threshold is lowered, the muscle will respond not only faster, but also to lower levels of stimuli.
Hypersecretory Gastric Syndrome
Hypersecretory Gastric Syndrome is the condition of abnormally increased secretion of gastric juices.
Hypertension
Hypertension is abnormally high arterial blood pressure.
Hypertext
Hypertext is text (appearing in electronic media) which is not constrained to be sequential; by using highlighted words and images, the user can access other web pages by clicking on the word or image, thus progressing through the information in a non-sequential manner.
Hypertonic
Hypertonic means having a higher concentration of osmotically active substances than the applicable standard (e.g., blood). A solution hypertonic to animal cells will cause a net flow of water across the cell membrane to the outside.
Hypertrophy
Hypertrophy is an increase in the size of a muscle or organ.
Hyperuricosuria
Hyperuricosuria is the increased excretion of uric acid in the urine.
Hyperventilation
Hyperventilation, or overventilation, is described by abnormally fast or deep respiration in which excessive quantities of air are taken in, causing buzzing in the ears, tingling in the extremities and sometimes fainting.
Hyphomycete
Hyphomycete is a class of fungi that produces asexual spores. They are widely distributed in soil and air.
Hypnotics
Hypnotics are a class of drugs often used as sedatives.
Hypocalcemia
Hypocalcemia is the presence of an abnormally low concentration of calcium in the urine.
Hypocalciuria
Hypocalciuria is the presence of an abnormally low concentration of calcium in the urine.
Hypocitraturia
Hypocitraturia is the decreased excretion of citrate in the urine.
Hypodermic syringe
A hypodermic syringe is a small syringe used with a hollow needle for injection or removal of fluids beneath the skin.
Hypokinesis
Hypokinesis is a condition of abnormally diminished motor activity.
Hyposecretory Gastric Syndrome
Hyposecretory Gastric Syndrome is the condition of diminished secretion of gastric juices.
Hypotension
Hypotension is a condition in which the arterial blood pressure is abnormally low. It occurs after excessive fluid loss or following severe blood loss from any cause.
Hypothalamus
The hypothalamus is the region of the brain which contains several important centers which control body temperature, thirst, hunger, water balance, and sexual function. It is also closely connected with emotional activity and sleep, and functions as a center for the integration of hormonal and autonomic nervous activity through its control of pituitary secretions.
Hypothesis
A hypothesis is an assumption not proved by experiment or observation that is made for the sake of testing its soundness.
Hypoventilation
Hypoventilation is reduced alveolar ventilation relative to metabolic production of carbon dioxide, so that alveolar carbon dioxide pressure increases above normal.
Hypovolemia
Hypovolemia (oligemia) is a decrease in the volume of circulating blood.
Hypoxemia
Hypoxemia is an abnormal deficiency of oxygen in the arterial blood.
Hypoxia
Hypoxia describes a state of below-normal levels of oxygen in the arterial blood or tissue. Six different kinds of hypoxia are defined by the various causes.
Hypoxic
Hypoxic refers to a decreased concentration of oxygen in the air or environment.
Hysteresis
Hysteresis is any situation in which the value of one variable depends upon whether the other has been increasing or decreasing.
Hz
Hertz
HZE particles
HZE, or high mass energy, particles are highly charged and energetic components of cosmic rays. These particles can deposit energy in tissue, possibly killing a cell if the particle passes to close to the cell’s nucleus.
I
Inspection
I-S
Interconnect Station
I/F
Interface
I/O
Input/Output
IA
Integration Area
IACO
Integration, Assembly and Checkout
IAW
In Accordance With
IBCS
Inflight Blood Collection System
IBM
International Business Machines
IC
Intercom
ICA
Intercom A
ICB
Intercom B
ICD
Interface Control Document
ICD
Interface Control Drawing
ICR
Interface Change Control Requirement
ICRP
International Commission for Radiation Protection
ICRS
Intercom Master Station
ICRS
Intercom Remote Station
ICS
Interpretive Computer Simulator
ID
Identification
IDAPS
Image Data Processing System
IDE
Initial Design Evaluation
Idiopathic
Idiopathic denotes a disease of unknown cause.
IDL
Indentured Drawing List
IDS
Item Description Sheet
IECMU
Induced Environment Contamination Monitor Unit
IEEE
Institute of Electrical and Electronic Engineering
IERD
Integrated Experiment Requirements Document
IF
Intermediate Frequency
IGES
Initial Graphic Exchange Specification
IGS
Investigator Ground Studies
IH/SR
Integrated Hardware/Software Review
IHF
Isothermal Heating Facility
IIA
Instrument Interface Agreement
Iliocostalis
The iliocostalis is the lateral division of the erector spinae, having three subdivisions: musculus iliocostalis lumborum, m. i. thoracis and m. i. cervicus.
ILS
Integrated Logistics System
ILSSE
Integrated Life Sciences Shuttle Experiments
IMBLMS
Integrated Medical and Behavioral Laboratory Measurement System
IMBP
Institute of Medico-Biological Problems
IMC
Image Motion Compensation
Immune cell
Immune cells attack unrecognized or foreign substances in the body in order to destroy harmful invaders and prevent infection and disease. See also B-cell or T-cell.
Immune system
The immune system provides the body with a defense against infection, afforded by the presence of circulating antibodies and white blood cells. Antibodies are manufactured specifically to deal with the antigens associated with different diseases as they are encountered, while white blood cells attack and destroy foreign particles in the blood and tissues, including antigen-antibody complexes.
Immunity
Immunity refers to the quality of being insusceptible to or unaffected by a particular disease or condition. Active immunity refers to a form of long-term, acquired immunity that protects the body against a new infection as a result of antibodies after an initial infection or artificially after immunization. Passive immunity refers to a form of immunity resulting from antibodies that are transmitted naturally through the placenta to a fetus or through the colostrum to an infant or artificially by injection of antiserum for treatment or prophylaxis. Passive immunity is not permanent and does not last as long as active immunity.
Immuno-hematology
Immuno-hematology is the study of antigen-antibody reactions and their effects on blood.
Immunocompetence
Immunocompetence pertains to the ability to produce a normal immune response.
Immunofluorescent antibody technique
The immunofluorescent antibody technique uses fluorescein-labeled antibodies to identify bacterial, viral or other antigenic material specific for the labeled antibody. Fluorescence microscopy is used to determine the specific binding of antibody through the production of a characteristic visible light that occurs upon application of ultraviolet rays to the preparation.
Immunoglobulin
An immunoglobulin is one of a class of structurally related proteins consisting of two pairs of polypeptide chains, one pair of light (L) low molecular weight chains and one pair of heavy (H) chains, all four linked together by disulfide bonds. On the basis of the structural and antigenic properties of the H chains, Ig’s are classified (in order of relative amounts present in normal human serum) as IgG, IgA, IgM, IgD and IgE. Antibodies are Ig’s, and all Ig’s probably function as antibodies.
Immunoglobulin A (IgA)
Immunoglobulin A (IgA) comprises about 10-15% of the body's total immunoglobulins. It is the major class of antibodies in external secretions, such as saliva, tears, breast milk, bronchial mucous and intestinal mucous. IgAs are secreted on the body’s surfaces as the first defense against bacterial and viral antigens thus preventing entry into the body. IgAs may be an important and effective antibody in areas other than mucosal tissues, such as the central nervous system.
Immunoglobulin D (IgD)
Immunoglobulin D is a blood protein characterized by it's unique heavy chain, the Delta class. IgD functions as an antibody and is found in the cell membrane of B lymphocytes.
Immunoglobulin E (IgE)
Immunoglobulin E is a blood protein characterized by it's unique heavy chain, the Epsilon class. IgE functions as a antibody and is found on the surface of basophils and mast cells. It is associated with allergic reactions.
Immunoglobulin G (IgG)
Immunoglobulin G (IgG), the most common type of antibody, comprises about 80% of the body's total immunoglobulins. It is the principal antibody in the serum and is produced in large quantities during secondary immune responses which, with IgM, activate the complement system. IgGs act on pathogens by agglutinating them, by opsonising them, by activating complement-mediated reactions against cellular pathogens and by neutralizing toxins.
Immunoglobulin M (IgM)
Immunoglobulin M (IgM) comprises 5-10% of the body's total immunoglobulins. It is the first antibody to appear in the serum after injection of an antigen and is produced during primary immune responses. It is capable of capturing and binding antigens to form large insoluble complexes which are readily cleared from the blood. IgM levels may be elevated in patients with delayed patterns of food allergy and manifest a protective defense response.
Immunohematologic
Immunohematologic refers to a branch of immunology that deals with the immunologic properties of blood.
Immunohistochemical
Interpersonal means being, relating to, or involving relations between persons.
Immunohistochemical
Immunohistochemical is the staining of tissues using monoclonal antibodies.
Immunological
Immunological relates to immunology, the study of the immune system. The immune system provides the body with a defense against infection via circulating antibodies and white blood cells. Antibodies are manufactured specifically to immediately deal with the antigens associated with different diseases as they are encountered, while white blood cells attack and destroy foreign particles in the blood and tissues.
Immunology
Immunology is the study of the immune system.
Immunophenotyping
Immunophenotyping is the recording of observable immunological characteristics of an individual, which result from interaction between the genes of that individual and the environment.
Immunoreactive
Immunoreactive is used to describe a situation where an antigen and antibody are reactive in vitro (occurring outside the body, traditionally in a test tube).
Immunoreactive growth hormone (IRGH)
Immunoreactive growth hormone (IRGH) is an interactive form of the growth hormone that also triggers immunoreactions (between antigen and antibody).
Impaction
Impaction means the effect of one thing on another.
Impactor
An impactor is a device that collects samples of particles suspended in air by directing a stream of the particle-containing air against a surface or into a liquid.
Impedance
Impedance is a measure of the total opposition to current flow in an alternating-current circuit.
Impinger
Impinger means to bear upon or put upon; a device that acts upon another (i.e. flames impinge on wood to make it burn).
Implantation
Implantation (nidation) is the attachment of the early embryo to the lining of the womb, usually six to eight days after ovulation. The site of implantation determines the position of the placenta.
in
Inch
IN
Incompatibility Notice
In vitro
In vitro is a Latin term describing biological phenomena that are made to occur outside the living body (traditionally in a test tube).
In vivo
In vivo is a Latin term describing biological phenomena that occur,or are observed occurring, within the bodies of living organisms.
In-situ
In-situ is the Latin term for "in the original place".
Inclination
Inclination is the degree of deviation from a horizontal or vertical line. The inclination of the Space Shuttle as it orbits the Earth is tracked during missions, since its inclination determines the stability of the spacecraft . At some inclinations, the Shuttle is more stable than others, which means it requires less fuel to keep it in orbit and provides a better environment for some gravity-sensitive experiments.
INCO
Instrument and Communications
Incubate
To incubate is to artificially warm (and hatch eggs) by maintaining conditions similar to body heat.
Incubation period
An incubation period is the time between exposure to a pathogenic organism and the onset of the symptoms of a disease.
Incubator
An incubator is a device that maintains controlled environmental conditions, including proper oxygenation, humidity and temperature. Some incubators are specifically designed to cultivate cell and bacterial cultures, while others are designed to hatch eggs or protect infants (usually premature).
Inertia
Inertia is the tendency of a body to resist acceleration, or to resist motion, action or change.
Inertial Measurement Unit (IMU)
The Inertial Measurement Unit (IMU) is a Shuttle orbiter navigation system which provides attitude and velocity data to the Guidance, Navigation, and Control (GNC) system.
Inertial property of mass
The inertial property of mass states that matter will remain at rest or in uniform motion in the same straight line unless acted upon by an external force.
Infiltrates
Infiltrates are substances that seep through a filter.
Influent
Influent refers to something which flows in or into.
Influenza
Influenza is an acute infectious respiratory disease, in which the inhaled virus attacks the respiratory epithelial cells of susceptible persons and produces an inflammation of the mucous membrane.
Influenza virus
Influenza virus is of the genus Orthomyxoviridae, which comprises the influenza viruses types A and B. Each type of virus has a stable nucleoprotein group antigen common to all strains of the type, but distinct from that of the other type; each also has a mosaic of surface antigens (hemagglutinin and neuraminidase) which characterize the strains. Strain notations indicate (1) type, (2) geographic origin, (3) year of isolation and (4) in the case of type A strains, the characterizing subtypes of hemagglutinin and neuraminidase antigens (e.g., A/HongKong/1/68 (H3N2)).
Infrared
Infrared is the part of the invisible spectrum that is contiguous to the red end of the visible spectrum.
Infrared anatomical photography
Infrared anatomical photography is a type of photography that uses heat sensitive film to see the regions of the body that give off heat.
INGRES
INGRES is a relational database management system for the VAX (Variable Access Exchange)
Inguinal
Inguinal is relating to the groin.
Innate
Innate means possessed as an essential characteristic; inherent.
Inner Ear
The inner ear (or labyrinth) is a convoluted system of cavities and ducts comprising the organs of hearing and balance.
Inoculate
Inoculate is to introduce a substance (inoculum) into the body to produce or to increase immunity to the disease or condition associated with the substance.
INOP
Inoperative
Inorganic
Inorganic means of or originating from non-carbon based compounds.
Inotropic
Inotropic means influencing the contractility of muscle tissue.
INS
Integrated Nitrogen System
Insomnia
Insomnia is a prolonged inability to obtain adequate sleep; abnormal wakefulness. Insomnia is actually a symptom that may be caused by many conditions, including stress, depression, pain, or similar problems.
INST
Install
Instl
Installation
Instr
Instrument
INSTR. WD
Instruction Word
Insulin
Insulin is a hormone secreted by the pancreas that promotes glucose utilization, protein synthesis, and the formation and storage of lipids. The chemical structure of insulin is completely known and insulin obtained from various animals is used in the treatment of diabetes.
Insulin like growth factor (IGF1)
Insulin like growth factor (IGF1), also known as somatomedin, is a peptide synthesized in the liver (and probably in the kidney) that is capable of stimulating certain anabolic processes in bone and cartilage, such as the synthesis of DNA and RNA protein and the sulfation of mucopolysaccharides. Its secretion and/or biological activity is known to be dependent on growth hormone (also called somatotropin).
INTEG
Integration
Integrated Metabolic Session
To minimize the amounts of blood, urine, and saliva taken from crew members, investigators share samples (e.g. one sample is drawn, processed and distributed to multiple investigators, who then perform their own unique analysis) in Integrated Metabolic Sessions.
Integumentary
Integumentary relates to the rind, capsule or covering of any body part.
Interaural axis
The interaural axis is the imaginary line that runs between and connects the auricles (outer ears).
Intercostal
Intercostal means between the ribs.
Intercrew
Intercrew means between two or more crewmembers.
Interdisciplinary physiology
The field of interdisciplinary physiology focuses on understanding how the changes in one system of the body affects another system. In space, many processes change as a result of the nearly complete loss of gravity's downward pull. For example, microgravity causes a headward shift in fluid which changes the normal state of physiology and affects several systems of the body.
Interferometer
An interferometer is a device that is used to study a sample of protein solution by passing a laser light through the sample.
Interferon Gamma
Interferon is a substance that is produced by cells infected with a virus and has the ability to inhibit viral growth. Gamma interferon is one of the three distinct types: alpha, beta and gamma.
Interindividual
Interindividual means between two or more individuals; e.g., interindividual differences.
Interleukin
Interleukin is a family of proteins that controls aspects of the production of blood cells and platelets (hemopoiesis) and the immune response. Eight interleukins are currently characterized; interleukin 2, for instance, stimulates T-lymphocytes and is being investigated for the treatment of cancer.
International Microgravity Laboratory (IML)
The International Microgravity Laboratory (IML) missions were a series of Spacelab missions that emphasized international cooperation between the European Space Agency (ESA), The Japanese Space Agency (NASDA), the Canadian Space Agency (CSA) and NASA. These missions were dedicated to the study of both life and microgravity sciences; the life sciences experiments focused on space biology (plant, cell, and molecular and developmental biology).
International partners
International partners, space agencies and scientists from foreign countries, cooperate with the United States space agency (NASA) and U.S. scientists to conduct experiments in space. For example, the International Microgravity Laboratory-1 (IML-1) was a cooperative effort between NASA and the European Space Agency, while the Spacelab-Mir missions are a cooperative effort between the U.S. and Russia.
Interpersonal
Interpersonal means being, relating to, or involving relations between persons.
Interpersonal
Immunohistochemical is the staining of tissues using monoclonal antibodies.
Interpupillary
Interpupillary means between the pupils.
Interstitial
Interstitial means relating to spaces or interstices (small area, space or hole in the substance of an organ or tissue) in any structure.
Interval exercise
Interval exercise is exercise in which periods of high intensity alternate with periods of low intensity.
Intervertebral
Intervertebral refers to the flexible plate of fibrocartilage that connects any two adjacent vertebrae in the backbone or spine.
Intervertebral disc
An intervertebral disc is the flexible plate of fibrocartilage that connects any two adjacent vertebrae in the backbone or spine.
Intervertebral disc space
The intervertebral disc space is the space between any two vertebrae of the backbone or spine containing the intervertebral disc, a flexible plate of fibrocartilage. During exposure to microgravity this space expands, causing a height change of up to 2 inches in the astronauts while in space.
Intestinal transit time
Intestinal transit time is the time required for a particle of food to move through the small intestine, that is, from the stomach to the cecum.
Intra-acinar
Intra-acinar means inside the acinus of the lungs. The term acinus refers to that part of the airway that contains the respiratory bronchiole and all of its branches.
Intra-carotid
Intra-carotid means inside the carotid artery.
Intracellular fluid
Intracellular fluid is the fluid located within cells.
Intracellular fluid volume (ICFV)
Intracellular fluid volume (ICFV) is the fluid volume located within cells.
Intraindividual
Intraindividual means between measurements from the same individual; e.g., intraindividual differences.
Intraocular
Intraocular denotes a location inside the eyeball.
Intraocular pressure
Intraocular pressure is the pressure within the eyeball.
Intraocular tension
Intraocular tension, also called intraocular pressure, is the pressure of the fluids of the eye.
Intraoral
Intraoral means within the mouth.
Intraperitoneal
Intraperitoneal refers to location within the serous membrane of the abdominal cavity called the peritoneum.
Intrapleural
Intrapleural refers to a location within the pleura, either the covering of the lungs (visceral pleura) or of the inner surface of the chest wall (parietal pleura).
Intravascular
Intravascular refers to any location within the system of blood vessels.
Intravenous
Intravenous means into or within a vein. An intravenous injection is made into a vein.
Intravenous (IV) pump
An IV pump is a mechanical pump utilized to inject or pump fluid or solution into a vein of the human body.
Intrinsic lower back muscles
Intrinsic refers to those muscles whose origin and insertion are both in the same limb or segment of a limb. Intrinsic lower back muscles have both their origin and insertion in the lower back.
Inutest
Inutest is a substance similar to the polysaccharide inulin. It is used to test the plasma clearance, or the ability of the kidneys to clean plasma of various substances. Glomerular filtrate and plasma are very similar, except that plasma contains all the proteins which are retained in the body and not cleared in the filtrate. Glomerular filtrate and plasma contain the same concentration of inulin, therefore all glomerular filtrate is cleared of inulin. So inulin is a good measure of glomerular filtration rate and plasma clearance.
INV
Inverter
Invertebrate
An invertebrate is any animal that does not have a backbone.
IOBPS
Input-Output Box and Peripheral Simulator
IOC
Initial Operational Capability
IOC
Integrated Operations Configuration
Iodine
Iodine is an element required in small amounts for healthy growth and development. An adult body contains about 30 mg of iodine, mostly concentrated in the thyroid gland where it is needed to synthesize thyroid hormones.
Iodine 131
Iodine 131 is a radioactive tracer that binds to blood albumin. It is used to measure total circulating blood volume.
Iodine-125 (I-125)
Iodine-125 (I-125) is a radioactive isotope of iodine. It is used as an active tracer that binds to serum plasma. By measuring the amount of radioactivity emitted by I-125, plasma volume can be measured. I-125 can also be used as a tracer in thyroid studies, as therapy in hyperthyroidism and thyroid cancer, and as a label in immunoassay.
Ion
An ion is an atom or group of atoms that has acquired an electric charge through the gain or loss of an electron or electrons.
Ion-selective electrode potentiometry
Ion-selective electrode potentiometry is the measurement of electrolyte concentration (activity, to be more precise) in a solution by using an electrode with a glass membrane that is permeable to only certain ions. These ions enter the immersed electrode until their concentration inside it is the same as that in the solution outside. A reference electrode is also immersed in the solution. The electrical potential difference across the ion-selective electrode membrane is measured with a sensitive voltage meter.
Ionization
Ionization is the process of disassociating atoms or molecules into ions. An ion is an atom, group of atoms, or molecule that carries a positive or negative electric charge as a result of having lost or gained one or more electrons.
Ionize
To ionize means to separate into ions; that is, to dissociate atoms or molecules into electrically charged atoms or radicals.
Ionized calcium
Ionized calcium is the ionic (i.e., charged) form of calcium that plays a role in muscle contractions and in regulating levels of parathyroid hormone (PTH).
Ionizing radiation
Ionizing radiation, such as that found in cosmic rays, causes atoms in the material through which it passes to lose electrons. The electrons are pulled away from the atoms by the strong attractive force between the positively charged proton (or heavy ion) and the orbital electron. Ionizing radiation can kill cells, damage their genetic material, and, in some instances, induce cancer.
IOP
Input-Output Processors
IOU
Input-Output Unit
IP
Internet Protocols
IP & CL
Instrumentation Program and Component List
IPA
Integrated Payload Analysis
IPGOR
Integrated Payload Ground Operations Review
IPL
Integrated Payload
IPMS
Implantation Medical Telemetry System
IPOTP
Integrated Payload Operations Training Plan
IPRD
Integrated Payload Requirements Document
IPRR
Integrated Payload Requirements Review
IPS
Instrument Pointing System
IR
Infrared
IRA
Investigation Resource Agreement
IRB
Investigation Resource Baseline
IRD
Interface Requirements Document
IRDP
Integration Readiness Data Package
IRI
Interagency Research Internet
Iridium (Ir)
Iridium is a member of the platnium group metals, also called the "noble metals," because they are among the scarcest of the metallic elements and are totally impervious to oxidation or corrosion. Iridium is a yellowish mineral with the highest corrosion resistance of any metal known. It's chemical symbol is Ir.
IRIG
Inter Range Instrumentation Group
IRN
Interface Revision Notice
Iron (Fe)
Iron is an essential element found in hemoglobin and myoglobin molecules. It is needed for hemoglobin production.
Iron economy
Iron economy refers to the measurement of red blood cell production and destruction by the process of using a radioactive isotope of iron as a type of tag. The radioactive iron is injected in harmless levels into the blood where it tags or marks the red blood cells. Afterwards, newly produced cells will be free of the isotope and destroyed, tagged cells can be counted. The balance between supply and destruction of red blood cells is termed iron economy.
Iron kinetics
Iron kinetics is the study of the rate of change of iron in the body.
IRR
Interface Requirements Review
Irritant
An irritant is something which causes inflammation, soreness, roughness, or irritability of a body part.
IS
Interconnecting Station
ISAMS
Improved Stratospheric and Mesospheric Sounder
ISDN
Integrated Services Digital Network
ISE
Impact Statement for Experiment
ISO
International Standards Organization
Isoagglutinin
Isoagglutinin is an isoantibody that causes cells to adhere or to form clumps.
Isocapnia
Isocapnia is a state in which carbon dioxide pressure in the arteries remains constant.
Isoenzyme
An isoenzyme (or isozyme) is one of a group of enzymes that are very similar in catalytic properties, but may be differentiated by variations in physical properties, such as isoelectric point or electrophoretic mobility.
Isokinetic
Isokinetic body movements occur at the same speed regardless of the force applied.
Isokinetic dynamometer
An isokinetic dynamometer is a device that measures the strength of different muscle groups.
ISOL
Isolation
Isolation
Isolation is the state of being free from external influence.
Isometric
Isometric describes the contraction of muscles when the fibers increase in tension, but do not shorten in length. Isometric exercises can be induced in muscles that are used when a limb is made to pull or push against something that does not move.
Isoproterenol
Isoproterenol is a chemical used as a drug which acts to stimulate the heart and open the air passages in asthma and other bronchial conditions.
Isotachophoresis
Isotachophoresis means "equal speed." The method consists of placing a mixture of charged particles (sample) of the same sign (co-ions) in a column or on some solid support medium containing two additional electrolytes. One electrolyte has co-ions more mobile than the sample co-ions, while the other electrolyte has co-ions less mobile than the sample co-ions. Upon application of a constant direct current, the sample co-ions initially move at different velocities until a steady state is reached. The sample ions will separate into contiguous zones with sharp interfaces in order of their mobilities. The boundaries are highly self-recuperative and will reform if stirred or disrupted by other factors, including convection.
Isothermal
Isothermal means with or at equal temperatures, or at a constant temperature.
Isotonic
Isotonic means balanced: under constant or uniform tension, or having the same concentration of osmotically active substances. An isotonic exercise is one in which a muscle contracts with a constant force, such as occurs when lifting a weight. A solution is isotonic if cells can be bathed in it without a net flow of water through the cell membrane, and two or more solutions are isotonic if they have the same concentration of osmotically active substances (salts, sugars, proteins, etc.).
Isotope
An isotope is one of two or more atoms of the same chemical element that have the same number of protons in their nucleus but different numbers of neutrons. Most elements in nature consist of a mixture of isotopes. Example: hydrogen is known to have three isotopes - hydrogen (1 proton, no neutrons), deuterium (1 proton, 1 neutron), and tritium (1 proton, 2 neutrons).
Isotopic
Isotopic refers to an isotope, the term used to describe that an element has two or more chemical properties, with the same number of protons, but different numbers of neutrons in their nucleus.
Isotypes
Isotypes refer to the classes of immunoglobulins IgG, IgA,IgM, IgD, and IgE which have similar structures but differ in molecular weight and concentration in the blood.
Isovelocity
Isovelocity is an equal or constant rate of movement, such as distance/time or work/time.
IST
Instrumentation Support Team
ISTP
International Solar Terrestrial Physics
IT
Information Transmittal (Ames Research Center)
ITE
Intersite Transportation Equipment
ITIP
International Technical and Integration Panel
ITT
Invitation to Tender
IU
Interface Unit
IUS
Inertial Upper Stage
IV&V
Independent Verification and Validation
IVA
Intravehicular Activity
IWFS
Integrated Waste Fluid System
IWG
Investigator Working Group
IWS
Integrated Water System
JB
Journal Bearing
JEM
Japanese Experiment Module
JESNet
JSC Research Engineering Directorate Network
JF
Jellyfish
JIS
Joint Integrated Simulations
JO
Job Order
Joystick
Joystick is a term used for the handhold tool used in many computer-based video games. The joystick is designed after the steering stick of military airplanes, allowing movement in all four directions as well as rotational movement. In addition, buttons with certain functions can be located at several positions on the joystick.
JPL
Jet Propulsion Laboratory
JPOC
Johnson Space Center Payload Operations Center
JSC
Lyndon B. Johnson Space Center
JSLWG
Joint Spacelab Working Group
Junctional rhythm
Junctional rhythm is an impulse that travels anterogradely and retrogradely at the same time. Depending upon the rate of conduction in each direction, the P wave may be inscribed shortly in front of the ventricular complex, may follow the QRS, or it may be lost within it.
JURG
Joint User Requirements Group
K
Kilo, 1000. When Denoting Data Rates
K
Kilo, 210 = 1024 10. When denoting computer memory size
K
One Thousand (SK or KBITS)
K-Sounds
K-sounds, or Korotkoff Sounds, are heard during the measurement of systolic and diastolic blood pressures when the cuff pressure is at a certain level. The cause of the K-sounds is still debated, but they are believed to be caused by blood jetting through the partly blocked or closed artery when the cuff is inflated. They resemble tapping noises and, when heard, indicate the systolic pressure by the manometer connected to the cuff.
Karyotype
Karyotype is the chromosome characteristics of an individual or of a cell line, usually presented as a systematic array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere.
KB
Keyboard
KBAUD
Code Elements per Second in 1,000's
KBITS
Kilobits
kbps
Kilobits per Second
Kbps/KB
Kilobits (1000s of bits) per second
KC-135
The KC-135 is a former military aircraft (a cargo version of the Boeing 707) purchased by NASA to simulate microgravity by performing parabolic flight maneuvers.
kcal
Kilocalorie
Kerley B Lines
Kerley B Lines (in radiology) are lines resembling interstitial infiltrate that appear on chest X-ray images and are associated with certain disease conditions; fine horizontal lines a few centimeters above the costophrenic angle in the chest X-ray.
Ketosteroid
A ketosteroid is a steroid-like chemical measured in the urine, which gives an indication of androgen production in the body. The major ketosteroids are androsterone, etiocholanolone and estrone.
kg
Kilogram
Kg/hr
Kilograms per Hour
KHz
Kilohertz (Kilocycles per Second)
KI
Konigsberg Instruments Inc. (BTS Vendor)
Kidney
The kidney is the main organ of excretion and osmoregulation in vertebrates, through which nitrogenous waste material (principally urine), water, and ions, etc. are eliminated from the body. In humans there is a pair of kidneys situated in the abdomen, below the diaphragm, on the back.
Kidney stone
A kidney stone is a hard pebble-like mass commonly composed of calcium oxalate that forms within the kidney. Some kidney stones cause pain and must be removed from the body using surgery or ultrasound techniques.
Killifish
Fundulus heteroclitus, or the killifish, is a small shallow-water minnow common along the Atlantic coast. The egg of the killifish is tough and transparent which allows easy laboratory manipulation and observation of embryo development without undue stress on the developing embryo. Killifish embryos were first flown on the Apollo Soyuz mission to study the development of the vestibular system.
Kilocalorie
A kilocalorie is the quantity of energy required to raise the temperature of one kg of water 1 degree celcius. It is 1000 times the value of a calorie.
Kilopascal (kPa)
Kilopascal (kPa) is a thousand pascals; the pascal is the international unit for pressure.
Kinematics
Kinematics is the study of motion and the forces required to produce it. This includes the different forces at work during the movement of a single part of the body, and more complex movements such as running and climbing.
Kinescope
Kinescope is a cathode-ray tube in a television receiver that translates the received signal into a picture on a luminescent screen.
Kinetic energy
Kinetic energy is energy associated with motion.
Kinetics
Kinetics is the study of acceleration, motion or rate of change.
Kjeldahl method
The Kjeldahl method is a way to chemically determine, in an organic sample, the total concentration of nitrogen that is present as ammonia or bound in organic compounds.
Klb
Kilopounds
Klebsiella pneumonia
Klebsiella pneumonia is a bacterial species found in soil and water, on grain, and in the intestinal tract of humans and other animals; it also occurs in association with several pathologic conditions, urinary tract infections, sputum, feces, and metritis in mares. Capsular types 1, 2, and 3 of this organism may be causative agents in pneumonia.
km
Kilometer
KMI
Kennedy Space Center Management Instruction
Knizocyte
A knizocyte is a red blood cell that has a pinched-triconcavity appearance.
Knurled
Knurled means having small ridges on the edge or surface.
Korotkoff Sounds (K-sounds)
Korotkoff Sounds or, K-sounds, occur during the measurement of systolic and diastolic blood pressures when the cuff pressure is at a certain level. The cause of the K-sounds is still debated, but they are believed to be caused by blood jetting through the partly blocked or closed artery when the cuff is inflated. They resemble tapping noises and, when heard, indicate the systolic pressure by the manometer connected to the cuff.
Kringle
Kringle is a triple-looped, disulfide-linked protein domains, found in some serine proteases and other plasma proteins, including plasminogen (5 copies), tissue plasminogen activator (2 copies), thrombin (2 copies), hepatocyte growth factor (4 copies), apolipoprotein A (38 copies).
KSC
John F. Kennedy Space Center
KUSP
Ku-Band Signal Processor
KVA
Kilo-Volt Amps
kW
Kilowatt
kWh
Kilowatt Hours
L
Left Side
L
Length
L (IV-1)
STS Integration Level at KSC
L&L
Launch and Landing
L&L
Line-To-Line
L&PSD1
Lunar and Planetary Sciences Division
L-17.5
17.5 hours prior to launch (launch minus 17.5 hours)
La
Level Absolute
Lab
Laboratory
Labeled
The term "labeled" means to mark substances in a way that they can easily be identified. In life sciences, substances in the body are labeled using stable isotopes or harmless radioactive components so that they can be traced, analyzed or measured.
Labeled water (H218O)
Labeled water (H218O) is a naturally occurring form of water which contains the rare 18O isotope of oxygen (the common isotope of oxygen is 16O).
Lability
Lability means instability, or easily altered or modified, e.g. chemical instability.
Labyrinth
The labyrinth is the system of cavities and tubes that comprises the inner ear of vertebrates. It is a system of membranous structures housed within a bony cavity. The labyrinth is the portion of the inner ear that is responsible for sensing balance. Inflammation of the labyrinth (labyrinthitis) can be accompanied by vertigo and deafness.
Labyrinthine
Labyrinthine means relating to the labyrinth.
Lactic (or Lactate) Dehydrogenase (LDH)
Lactic (or Lactate) Dehydrogenase (LDH) is an enzyme found in many body tissues especially heart, liver, kidney, skeletal muscle, brain blood cells, and lungs and is involved in basic cellular metabolism. Measurement of LDH isoenzymes is helpful in differentiating the source (location) of tissue damage. LDH exists in 5 forms, called isoenzymes, which differ slightly in structure. LDH-1 is in highest concentrations in heart muscle and red blood cells. LDH-2 is highest in white blood cells. LDH-3 is highest in the lung. LDH-4 is highest in the kidney, placenta, and pancreas. LDH-5 is highest in the liver and skeletal muscle. All of these isoenzymes can be measured in the blood.
Lactulose
Lactulose is a nonabsorbable synthetic sugar used as a cathartic (laxative) in chronic constipation or in the treatment of hepatic coma. It is also used in studies of gastrointestinal transit time because it is not digested until it reaches the large intestine.
Laminar flow
Laminar flow is a nonturbulent flow in parallel layers that have different velocities.
LAMR
Large Aperture Microwave Radiometer
LAN
Local Area Network
Landing
Landing refers to the day and time when the spacecraft returns back to Earth. It is sometimes abbreviated as R+0 to indicate zero days after landing day.
LANDSAT
Land Satellite
LaRC
Langley Research Center
Large intestine
The large intestine consists of the cecum, vermiform appendix, colon, and rectum. Its primary role is the excretion of non-absorbed material passed from the small intestine, and water absorption.
LARS
Laboratory for Applications of Remote Sensing, Purdue University
Larvae
Larvae refers to the juvenile stage of most invertebrates, amphibians, and fish, which all hatch from eggs. It is unlike the adult in form and is usually incapable of sexual reproduction. It develops into the adult by undergoing metamorphosis. Examples are the tadpoles of frogs or caterpillars of butterflies.
Larynx
Larynx is the upper part of the respiratory tract between the pharynx and the trachea, having cartilaginous walls and containing the vocal cords.
LASA
Laser Atmospheric Sounder and Altimeter
Laser
A laser is a device that concentrates high energies into a narrow beam of non-spreading, monochromatic light.
Latency
Latency refers to the period between nerve stimulation and response.
Latent infection
A latent infection is an infection by a virus in which the virus lays dormant in the host cell.
Lateralis
The term lateralis indicates that a structure is located away from the mid-line of the body.
Latitude effect
Latitude effect is a variation of a quantity with latitude, especially an increase in cosmic-ray intensity with increasing magnetic latitude.
lb
Pound
LBE
Code for Ames Research Center Life Sciences Flight Experiments Project
lbm
Pounds Mass
LBR
Low Bit Rate
LCC
Launch Control Center
LDAR
Laser Radar
LDEF
Long Duration Exposure Facility
LDL
Low Density Lipoproteins
LDR
Large Deployable Reflector
Lean body mass
Lean body mass is the weight of the body minus the fat content, or, in other words, the body mass without the fat.
LEB
Lower Electronics Box
Lectin
A lectin is a plant (usually seed) or animal protein that affects agglutination, precipitation, or other phenomena resembling the action of specific antibody, but that is not an antibody in that it was not evoked by an antigenic stimulus.
Left ventricular end-diastolic volume index (EDVI)
Left ventricular end-diastolic volume index (EDVI) is the volume measured in the left ventricle at the end of diastole (period of the heart's relaxation), with body size taken into account.
Left ventricular end-systolic volume index (ESVI)
Left ventricular end-systolic volume index (ESVI) is the volume measured in the left ventricle at the end of systole (period of the heart's contraction), with body size taken into account.
Left ventricular stroke volume
Left ventricular stroke volume, also called stroke volume, is the volume of blood (normally about 70 milliliters) ejected into the aorta during the contraction of the heart's ventricles.
Leg volume
Leg volume refers to the actual volume of the leg, a measurement taken to indicate changes in muscle size, either associated with changes in muscle size, or in the amount of fluid located in the tissues of the leg. Often taken during space flight or bed rest studies that are investigating changes in fluid volume or muscle size.
Lentil
A lentil is the round, flattened, edible seed of a pea-like Old World plant also called a lentil. It is a member of the leguminosae group - plants with the ability to use nitrogen in the air for nutrition.
LEO
Low Earth Orbit
Leptocyte
A leptocyte is a red blood cell characterized as being thin and flat in appearance.
Leq
Level Equivalent
LeRC
Lewis Research Center
Lesion
A lesion is a scar, or tissue that is damaged.
LET
Light Energy Transfer
Leukemia
Leukemia is any group of malignant diseases in which the bone marrow and other blood forming organs produce increased numbers of leukocytes (white blood cells).
Leukocyte
A leukocyte is a white blood cell, specifically a colorless cell with a nucleus, found in blood and lymph. Leukocytes are capable of amoeboid movement. They can produce antibodies and move through the walls of vessels to migrate to sites of injury, where they isolate and destroy dead tissue, foreign protein and bacteria.
Leukocytosis
Leukocytosis is an abnormal increase in the number of circulating white blood cells, which usually accompanies bacterial, but not viral, infections. Types of leukocytosis are basophilia, eosinophilia, and neutrophilia.
Leukopenia
Leukopenia is a reduction in the number of white blood cells (leukocytes) in the blood.
Leukotriene
One of a group of hormones that cause the symptoms of hayfever and asthma. Derived from arachidonic acid, the leukotrienes act by mediating immediate hypersensitivity.
Lexan
Lexan is a trademark name for polycarbonate, which is any of a family of thermoplastics characterized by high-impact strength, flexibility, and light weight; it is used as a shatter-resistant substitute for glass.
LF
Load Factor
LFMR
Low Frequency Microwave Radiometer
LH
Left Hand
LH2
Liquid Hydrogen
LHCP
Left Hand Circularly Polarized
Libration
Libration is an oscillation in the apparent aspect of a secondary body (such as a planet or satellite) as seen from the primary object around which it revolves.
Libration clouds
Libration clouds are small celestial particles trapped in regions of the Earth-Moon system where gravitational and centrifugal forces acting on them cancel each other.
LIF
Life Sciences
Life support systems
Life support systems are the hardware and resources that provide the necessities vital for life, namely, oxygen, water and food for space travelers. Temperature regulation, carbon dioxide removal and waste management systems are considered subsystems of life support systems.
Ligament
Ligaments are resilient but flexible tissues which hold two or more bones together at a movable joint. Ligaments restrain the movement of bones at a joint and are therefore important in preventing dislocation. They consist primarily of collagen.
Light Emitting Diode (LED)
A Light Emitting Diode (LED) is a very small light often used in electronic instrumentation.
Light flash phenomenon
Light flash phenomenon is a visual phenomenon or event that is experienced when a person is exposed to cosmic ionic particles, similar to, but brighter than, a shooting star in the night sky. Although the exact cause of this phenomenon is unknown, it is believed that visual flashes result from direct ionizing energy loss as the particle traverses the cells of the eye.
Light microscopy
Light microscopy is the inspection of a substance or object with the use of a light microscope. A light microscope uses visible light to help provide an enlarged image of an object or substance that is very small or not visible to the naked eye.
Light scatter
Light scatter is the deflection of a light beam by obstacles, such as dust particles, in a medium such as air.
Light unit
The light unit of the Svet greenhouse is inserted into the top of the growth chamber and can be set at three different positions, at distances of 20, 30 and 40 centimeters from the root module surface, to allow for maximum illumination during plant growth. It contains six units that each contain fluorescent bulbs.
Lignin
Lignin is a substance related to cellulose that provides rigidity and together with cellulose forms the woody cell walls of plants and the cementing material between them.
Linear acceleration
Linear acceleration is the rate of change of velocity in a linear direction (along a straight line) with respect to time.
LiOH
Lithium Hydroxide
Lipase
Lipase is an enzyme, secreted by the pancreas and the glands of the small intestine, that breaks down fats into glycerol and fatty acids during digestion.
Lipid
A lipid is one of a group of naturally occurring compounds, also known as fats, that are soluble in organic solvents such as chloroform or alcohol, but insoluble in water. Lipids are important dietary constituents, not only because of their high energy value, but also because certain vitamins and essential fatty acids are associated with them.
Liquid scintillation counter
Scintillation counting is a technique for measuring the quantity of a radioactive isotope present in a sample. In biology, liquid scintillation counting is mainly used for isotopes such as carbon 14, sulfur 35 and phosphorous 32 and particularly for the low energy emission of hydrogen 3. Gamma emissions are often measured by counting the scintillations that they cause in a crystal. Autoradiographic images can be enhanced by using a screen of scintillant behind the film.
Liquid-liquid diffusion crystallization
Liquid-liquid diffusion crystallization is a technique used for growing protein crystals. It consists of a protein solution and precipitating solution separated by an liquid interface. Diffusion across the interface saturates the protein solution causing the proteins to crystallize.
Lithium chloride (LiCl2)
Lithium chloride is a substance used as an inert tracer in the determination of fluid volume by the lithium dilution technique.
Liver
The liver is the largest gland of the body, weighing between 1200-1600 grams, and is situated in the top right portion of the abdominal cavity. The liver is divided by fissures into four lobes. The liver plays an essential role in many metabolic processes by regulating the composition and concentration of nutrients and toxic materials in the blood. Its functions include synthesizing bile and blood coagulating factors, acting as the site of metabolism of carbohydrates, proteins and fats, regulating the amount of blood sugar, converting excess glucose to glycogen, removing excess amino acids, storing and metabolizing fats, and detoxifying poisonous substances, worn out red blood cells and other unwanted material.
LIVIR
Level IV Integration Requirements
LIVR
Level IV Readiness
LL-TV
Low Light Level Television
LLPRD
Launch and Landing Program Requirements Document
LM
Long Module
LMMI
Large Mass Measurement Instrument
LMSC
Lockheed Missiles & Space Company
LN2
Liquid Nitrogen
LNH
Launch
LNK
Link
Load
A load is the overall force to which a structure is subjected in supporting a weight or mass or in resisting externally applied forces.
Loading
The term loading refers to gravitational loading, or the application of force to a bone or part of the body. Under normal circumstances on Earth, gravity "loads" the bones and muscles with the force required to support the body.
Local
Local means having reference or confined to a limited area, not general or systemic.
Locomotion
Locomotion is the act of moving, or the ability to move, from place to place.
Locomotor
Locomotor refers to locomotion, the ability of an organism to move in a particular direction in its environment. In animals, the force required to initiate locomotion is generated by voluntary muscle contractions.
Locus ceruleus
The locus ceruleus is a small pigmented region in the floor of the fourth ventricle of the brain; the region is made up of about 20,000 melanin-pigmented neuronal cell bodies whose norepinephrine-containing axons have a remarkably wide distribution in the cerebellum as well as in the hypothalamus and cerebral cortex of the brain.
LOE
Level of Effort
Log
A log is a detailed record of a voyage, flight, or experiment. It may be specific to food, exercise, medications, etc.
Lomotil
Lomotil is the trademark for an antidiarrheal fixed-combination drug containing an antiperistaltic and an anticholinergic.
Longissimus
The longissimus is the intermediate division of the erector spinae muscle having three subdivisions: musculus longissmus capitus (keeps the head erect), m. l. cervicus (extends cervical vertebrae) and m. l. thoracis (extends the vertebral column).
Lordosis
Lordosis is the normal curvature of the lumbar and cervical spine, seen as an anterior concavity if the person is observed from the side.
LOS
Loss of Signal (Telemetry)
LOS
Loss of Sight
Lower Body Negative Pressure (LBNP)
Lower body negative pressure (LBNP) is applied by placing the lower body (legs and hips) in a sealed chamber. Suction applied to the chamber causes body fluid to move from the chest and upper body to the lower body. This shift of fluid is very similar to the shift of fluid that occurs when people stand upright.
LOX
Liquid Oxygen
LP
Line Printer
LPF
Large Primate Facility
LPS
Launch Processing System
LQP
Letter Quality Printer
LRSI
Low Temperature Reusable Surface Insulation
LRU
Line Replaceable Unit
LRV
Launch Readiness Verification
LS
Life Sciences
LS-1
Life Sciences 1 (Mission)
LSA
Large Space Antenna
LSB
Least Significant Bit
LSDA
Life Sciences Data Archive
LSDF
Life Sciences Data Facility
LSE
Life Sciences Experiments
LSFEP
Life Sciences Flight Experiments Program
LSFP
Life Sciences Flight Projects
LSGSSS
Life Science Guide to the Space Shuttle and Spacelab
LSI
Launch Site Integration
LSI
Large Scale Integrated
LSIS
Life Sciences Information System
LSL
Life Sciences Laboratory
LSLE
Life Sciences Laboratory Equipment
LSPD
Life Science Project Division
LSPDPM
Life Science Payload Development Program Management Plan
LSPE
Launch Site Payloads Engineer
LSPIWG
Life Science Payload Inter-Center Working Group
LSPO
Life Sciences Projects Office
LSPS
Life Support and Protective Systems
LSRF
Life Sciences Research Facility
LSSC
Life Sciences Steering Committee
LSSF
Life Sciences Support Facility
LSSM
Launch Site Support Manager
LSSP
Launch Site Support Plan
LSSSPO
Life Sciences Space Station Projects Office
LSST
Launch Site Support Team
Lumbar
Lumbar means relating to the loins, or the part of the back and sides between the ribs and the pelvis.
Lumbar 3
The lumbar 3 is the third vertebrae (counted from the head) of the lumbar spine.
Lumbar spine
The lumbar spine, or lumbar vertebrae, are the five bones of the backbone that are situated between the thoracic vertebrae and the sacrum in the lower part of the back. They are the largest of the unfused vertebrae and have stout processes for attachment of the strong muscles of the lower back.
Lumbar vertebrae
The lumbar vertebrae are the five bones of the backbone that are situated between the thoracic vertebrae and the sacrum in the lower part of the back. They are the largest of the unfused vertebrae and have stout processes for attachment of the strong muscles of the lower back.
Lumbosacral
Lumbosacral refers to the group of motor neurons which connect the lower spinal cord to muscles of the lower back, gluteal region, and various other parts of the body.
Luminous
Luminous means emitting light.
Lung water
Lung water is the fluid in the pulmonary extravascular space. Excessive water accumulates in the lung during disease or when edemas are present. The lung water causes impaired perfusion and breathing, depriving the body of oxygen.
LV
Local Vertical
LVL
Level
LVLH
Local Vertical Local Horizontal
Lymph nodes
Lymph nodes are one of a number of small swellings found at intervals along the lymphatic system. Groups of nodes are found in many parts of the body; for example, in the groin and armpit and behind the ear. They are composed of lymphoid tissue and act as filters for the lymph, preventing foreign particles from entering the bloodstream; they also produce lymphocytes.
Lymphocyte
A lymphocyte is a type of white blood cell present in blood, lymph nodes, spleen, thymus gland, gut wall and bone marrow. Important to the immune system, they produce circulating antibodies and T-lymphocytes, which are primarily responsible for cell-mediated immunity and can differentiate into helper, killer or suppressor cells.
Lymphocyte proliferation
Lymphocyte proliferation means that after lymphocytes encounter an antigen or foreign protein, they begin a process by which they rapidly reproduce themselves, so that there are many lymphocytes available which can recognize and fight the invading antigens.
Lymphokine
A lymphokine is a soluble substance released by sensitized lymphocytes on contact with specific antigen, which help effect cellular immunity by stimulating activity of monocytes and macrophages. These include chemotactic, mitogenic, migration-inhibitory, transfer factors, lymphotoxin and immune (antigen) interferon.
Lymphoma
A lymphoma is any malignant tumor of the lymph nodes, including Hodgkin's disease.
Lymphopenia
Lymphopenia is a decrease in the number of lymphocytes (a variety of white blood cells) in the circulating blood, which may occur in a wide variety of diseases.
Lyophilyzed
Lyophilized or lyophilization is the process of freeze-drying, which is the removal of liquid from heat-sensitive materials. The material is frozen, placed under a high vacuum, and maintained at a low temperature. The pressure generated by the vacuum causes the ice to turn from a solid to a gaseous form without passing through a liquid state.
Lysis
Lysis is a rupture of cell membranes and loss of cytoplasm.
Lysozyme
Lysozyme is an enzyme that hydrolyzes the 1,4-beta links between N-acetylmuramic acid and N-acetylglucosamine, and thus destructive to cell walls of certain bacteria. It is present in tears and other body fluids, in egg whites and in some plant tissues.
m
Meter, Milli
M
Million
M
Mega = 106 when denoting data rates
M&P
Materials and Processes
M-S
Mission Station
m/s2
Meters per Second Squared
M2
Mega 2 = 1,048,576 When Denoting Computer Memory Size
m2
Meters Squared
M2
Mission Management
m3
Cubic Meters
Macromolecular
Macromolecular describes a molecule of colloidal size such as proteins, nucleic acids, and polysaccharides.
Macromolecule
A macromolecule is a polymer, especially one composed of more than 100 repeated monomers (which are single chemical units). A biological macromolecule is one which is involved in the processes of life and living organisms, such as proteins (haemoglobuliu) and deoxyribonucleic acid or DNA.
Macrophage
A macrophage is a large scavenger cell present in connective tissue and many major organs and tissues including the bone marrow, spleen, lymph nodes, liver and the central nervous system. Macrophages ingest bacteria and cell debris and are responsible for the breakdown of worn-out red blood cells.
Macula
The macula is a small anatomical area in the inner ear and the eye; it contains an increased number of nerve cells. In the inner ear, it is the patch of sensory hair that provides information about the position of the body in relation to gravity, also known as the otolith organ of the ear. In the eye, the macula is a shallow depression in the retina of the eye, opposite the lens. It contains a large concentration of cones and is specialized for the perception of color and sharp intense images.
Magnesium (Mg)
Magnesium is a silvery metallic element essential to life. It is necessary for the proper functioning of muscle and nervous tissue and is involved in the transmission of nerve impulses.
Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging (MRI) is a noninvasive, nondestructive method of creating three-dimensional, internal images of the soft tissues of the body, including the brain, spinal cord and muscle by applying a magnetic field to the body in a constant radio frequency field. MRI is an application of nuclear magnetic resonance, and depends on measurement of the magnetic moment of hydrogen atoms in the body to determine structure.
Magnitude
Magnitude is a property that can be quantitatively described, such as the volume of a sphere or the length of a vector.
Malaise
Malaise is an indefinite feeling of weakness or lack of health which is often indicative of or accompanying the onset of an illness.
Mammalian
Mammalian means referring to mammals, a class of vertebrates containing some 4250 species. Mammals are warm-blooded animals, typically having sweat glands whose secretion cools the skin and an insulating body covering of hair. All mammals have mammary glands, which secrete milk to nourish the young.
Mandible
The mandible is the lower jawbone of vertebrates; either of the two parts of a bird's beak; and a pair of horny mouth parts in insects, crustaceans, centipedes, and millipede, assisting in biting and crushing the food.
Manometer
A manometer is an instrument used to measure the pressure of any fluid or the difference in pressure between two fluids, whether gas or liquid.
Marangoni convection
Marangoni convection is the primary surface tension-driven force in a float zone. Thermal gradients along the free surface of the float zone drive the convection.
MAS
Macro Assembler
Mass
Mass is the characteristic of a body that is considered a measure of the amount of material it contains and causes it to have weight in a gravitational field. The mass of a body always has the same value; weight changes with change in the acceleration of gravity.
Mass spectrometer
A mass spectrometer is an instrument used for measuring the intensity and wavelengths of visible or invisible electromagnetic radiation.
Mass spectrometry
Mass spectrometry is a procedure used to identify chemicals by ionizing them and sorting the ions by mass and electrical charge.
Mastoid process
The mastoid process is the nipple-like projection of the petrous part of the temporal bone.
MAWP
Maximum Allowable Working Pressure
max
Maximum
Maxilla
For vertebrates, the maxilla is the upper jaw, which bears the upper teeth (except the incisors). For insects, crustaceans, centipedes, and millipedes, it is a mouth part assisting in feeding.
Maxillary sinusitis
Maxillary sinusitis is an inflammation of the one or more paranasal sinuses. It may be a complication of an upper respiratory infection, dental infection, allergy, a change in atmosphere, or a structural defect of the nose.
Maximal aerobic work capacity
Maximal aerobic work capacity (also called maximal exercise capacity) is the maximum ability of the body to take up and use oxygen to do work. This is often reported as the maximum number of liters of oxygen that the body can use in a minute.
Maximal exercise capacity
Maximal exercise capacity (also called maximal aerobic work capacity) is the maximum ability of the body to take up and use oxygen to do work. This is often reported as the maximum number of liters of oxygen that the body can use in a minute.
Maximal Expiratory Flow Volume (MEFV)
The Maximal Expiratory Flow Volume (MEFV) occurs when a person expires with great force, and the expiratory air flow reaches a maximum flow beyond which the flow cannot be increased even with greatly increased additional force.
Maximal heart rate
Maximal heart rate is two-hundred twenty (220) minus the subject's age in years.
Maximal oxygen consumption (max VO2)
Maximal oxygen consumption is the point at which the oxygen consumption plateaus and shows no further increase (or increases only slightly) with an additional workload. Also called maximal oxygen uptake, maximal aerobic power, or max VO2.
Maximum voluntary contraction (MVC)
A maximum voluntary contraction (MVC) is the largest force that can be voluntarily exerted by a muscle.
MB
Megabyte
MBD
Company, Graphics System Vendor
MBE
Molecular Beam Epitaxial
MBIS
Mobile Biological Isolation Station
MBITS
Megabits
mbps
Megabits per Second
Mbyps
Megabytes per Second
MCC
Mission Control Center
MCDS
Multifunction CRT Display System
MCS
Material Control System
MCS
Material Control Station
MD
Man Day
MD
Mission Day
MDAC
McDonnell Douglas Astronautics Company
MDE
Mission Dependent Equipment
MDM
Multiplexer-Demultiplexer
MDP
Mission Definition Phase
MDS
MITS Data Software
MDTSCO
McDonnell Douglas Technical Service Company
ME
Main Engine
Mechanical properties
Mechanical properties are measurements pertaining to the strength and flexibility of bones, including the amount of stress and strain the bone can tolerate before breaking.
Mechanical systole
Mechanical systole is the rhythmically recurrent muscular contraction of the heart.
MECO
Main Engine Cutoff
Median eminence
The median eminence is an enlarged area of the infundibulum where it arises from the inferior border of the hypothalamus. This is a region in the brain where nerve terminals actually secrete their releasing and inhibitory hormones, which are then absorbed into the blood capillaries in the median eminence and carried in the venous blood down along the infundibulum, a funnel-like structure or passage, to the anterior pituitary gland.
MEDICS
Medical Information Computer System
Medilog Sleep Research Recorder (MSRR)
The Medilog Sleep Research Recorder system is a data recorder connected to a sleep cap with 10 electrodes which attach to the head. The system provides data about brain waves (electroencephalography (EEG)), eye movements (electro-oculography (EOG)), and muscle tone (electromyography (EMG)) while the crewmember is sleeping.
Medulla oblongata
The medulla oblongata (myelencephalon) is the extension, within the skull of the upper end of the spinal cord, forming the lowest part of the brain stem. Besides forming the major pathway for nerve impulses entering and leaving the skull, the medulla regulates the reflex responses controlling respiration, heart beat, blood pressure, and adhere involuntary processes.
MEG
Magnetoencephalogram
Megaelectron volt
The energy possessed by an electron is called an electron volt (eV). One eV is the amount of kinetic energy gained by an electron as it accelerates through an electric potential difference of one volt. It is usually more convenient to use a larger unit such as megaelectron volt (MeV), which is equal to one million electron volts.
Melatonin
Melatonin is a hormone secreted by the pineal gland in the brain; it is distributed throughout the body by the blood. Exposure to light increases the secretion rate. Melatonin regulates seasonal physical and physiological changes in many species. In humans, it may help regulate reproductive cycles, sleep, and other processes related to time or age.
Meninges
Meninges are membranes, specifically the membranous coverings of the brain and spinal cord.
Meningitis
Meningitis is the inflammation of the membranes of the brain and spinal cord.
MER
Mission Evaluation Room
Meristem
A meristem is a plant tissue usually made up of small cells that are capable of dividing indefinitely and give rise to similar cells or cells that differentiate into definitive tissues and organs (flowers).
Mesencephalon
The mesencephalon is the part of the brain lying between the forebrain and hindbrain. The trochlear and oculomotor nerves arise in the mesencephalon, and it contains structures important in the visual and auditory pathways, as well as other structures. The embryonic mesencephalon develops into the adult mesencephalon.
Mesophyll
Mesophyll is the internal tissue of a plant leaf, excluding the vascular bundles. All mesophyll cells contain chloroplasts, for photosynthesis, which lie close to the edge of the cell to gain maximum light and gas supply. Mesophyll tissue also contains numerous intercellular spaces, which communicate with the atmosphere outside the leaf via stomata.
Messenger Ribonucleic acid (mRNA)
Messenger Ribonucleic acid (mRNA) is a transcription of a gene that combines with ribosomal RNA (rRNA) and transfer RNA (tRNA) to facilitate protein synthesis.
MET
Mid-Expiratory Time
Metabolic
Metabolic means of or relating to metabolism.
Metabolic analyzer
A metabolic analyzer is equipment used to measure oxygen and carbon dioxide during respiration.
Metabolic deficiency
A metabolic deficiency describes a condition in which the metabolic pathways responsible for producing cells, tissue and energy are operating below normal levels. A primary reason for this deficit is insufficient food intake.
Metabolic gas
Metabolic gases are released by the body as a result of metabolism, the step-wise breakdown or creation of complex organic constituents in the body. The process results in the liberation of energy used by the body and its processes. Carbon dioxide is an example of a metabolic gas.
Metabolic rate
Metabolic rate is the amount of energy liberated or expended in a given unit of time.
Metabolic system
The metabolic system governs the chemical and physical changes that take place within the body that enable its continued growth and function. Metabolism involves the breakdown of complex organic constituents of the body in order to liberate energy for all the bodily processes and the building up of complex substances, which form the material of the tissues and organs.
Metabolism
Metabolism is the sum of all chemical and physical changes that take place within the body enabling its continued growth and operation. Metabolism involves the breakdown or creation of complex organic constituents of the body with the liberation of energy, which is required for vital processes and activities, including the formation of tissues and organs.
Metabolism and nutrition
Metabolism and nutrition is the area of research which investigates how space flight affects the body's needs for energy and nutrients.
Metabolite
A metabolite is a substance that is produced by metabolism, the breakdown of complex organic constituents of the body with the liberation of energy for use in body functions.
Metamorphosis
Metamorphosis is the rapid transformation from the larval to the adult form that occurs in the life cycle of many invertebrates and amphibians. Examples are the changes from a tadpole to a frog, or from a caterpillar to a butterfly.
Metaphase
Metaphase is one of four stages of mitosis (prophase, metaphase, anaphase and telephase) for which the cell prepares to split into two cells by bringing the chromosomes to the center of the cell. Metaphase is the stage of mitosis or meiosis in which chromosomes become aligned on the equatorial plane of the cell with the centromeres mutually repelling each other. In mitosis, the centromeres of each chromosome divide and the two daughter centromeres are directed toward opposite poles of the cell.
Metaphysis
The metaphysis is the growing portion of a long bone that lies between the epiphyses (the ends) and the diaphyses (the shaft).
Metatarsal
The metatarsal region of the foot lies between the ankle/heel complex and the phalanges (toes).
Meteorology
Meteorology is the science of the Earth's atmosphere, especially weather conditions.
Methane
Methane is an odorless gas produced by the decomposition of organic matter.
Methemoglobin
Methemoglobin is a transformation product of oxyhemoglobin because of oxidation of the normal ferrous to ferric, thus converting ferroprotophophrin to ferriprotophophyrin. It is found in sanguineous effusions and in the circulating blood after poisoning with acetanilid and other substances. Methemoglobin contains oxygen in firm union with ferric iron.
Methylcellulose
Methylcellulose is a form of cellulose, a natural carbohydrate polymer, which can be used as a film coating, a sealer for tablets, or a thickener and suspending agent.
METT
Microwave Energy Transmission Test
MFLOPS
Million Floating Point Instructions Per Second
MFR
Mobile Foot Restraint
mg
Milligram
mg/hr
Milligrams per Hour
MGR
Manager
MGSE
Mechanical Ground Support Equipment
MHF
Mirror Heating Facility
MHz
Megahertz (Megacycles per Second)
mi
Mile
MIA
Mission Implementation Agreement
MIC
Management Information Center
Micro-Kjeldahl
Micro-Kjeldahl is a procedure for analyzing the content of nitrogenous compounds in urine, serum or other specimens. It is a modification of the macro-Kjedahl method designed for the analysis of nitrogenous compounds in relatively small quantities, such as specimens in which the total content of nitrogen is in the range of 1 to a few milligrams.
Microacceleration
Acceleration is measured as the rate of change of velocity with respect to time. Microacceleration is a minute (very small) acceleration force.
Microbe
A microbe, also called microorganism, is any organism too small to be visible to the naked eye. Bacteria, viruses, protozoans, certain fungi and some algae are microorganisms.
Microbial
Microbial means of or relating to microorganisms.
Microbial ecology
Microbial ecology is the study of the interactions between living microorganisms and their environment.
Microbial shock
Microbial shock is a condition in which crewmembers respond negatively to renewed contact with potentially pathogenic microorganisms on Earth that were absent in the space flight environment.
Microbiology
Microbiology is the study of microorganisms, such as bacteria, viruses, certain fungi and some algae. Microbiology was first directed towards the effects (e.g. disease and decay) caused by microorganisms, but has shifted during the last 100 years to their physiology, biochemistry and genetics.
Microbiota
Microbiota are microscopic organisms in a specific environment.
Micrococcus
Micrococcus is a genus of bacteria having gram-positive, spherical cells that occur in irregular masses; some may be motile. Some species are commonly found in milk and dairy products.
Microcurie
Microcurie is a measure of radium emanation, one-millionth of a curie; 37,000 disintegrations per second.
Microecology
Microecology refers to the study of the interactions between living microorganisms and their environment.
Microflora
Microflora are the plants and algae that cannot be seen with the naked eye.
Microgravity (0-G)
Microgravity is a state in which gravity is reduced to almost negligible levels, such as during space flight.
Microgravity Glove Box (MGBX)
The Microgravity Glove Box, or MGBX, provides a clean and sealed work cabinet for the preparation and performance of experiments within the laboratory environment of the Priroda module of the Russian Space Station Mir. Experiments are inserted into the unit and manipulated by the crewmembers, who grab the experiment hardware and tools through plastic gloves. The MGBX prevents experiment materials from entering the module atmosphere and provides basic services to the experiments, such as electrical power, lighting, data recording, cooling, some small stowage, air circulation, air filtering, gas sensing, and a means for manual observation and video recording by the crew. The MGBX also monitors temperature, pressure, and humidity. Experiments involving combustion, hazardous operations, or experiments that need to be isolated from the normal Mir environment can be accommodated with the MGBX.
Microgravity Sciences
Microgravity Sciences is a research program which studies fundamental science, combustion science, materials science and biotechnology in the space environment in order to better understand gravity dependent physical phenomena.
Micrometeorite
A micrometeorite is a meteorite so small that it can pass through the earth's atmosphere without becoming intensely heated. Micrometeorites are common in outer space and earth orbit, where they are capable of damaging spacecraft since they impact at such high velocities.
Micrometeoroid
A micrometeoroid is a relatively small celestial body or rock fragment.
Micrometer
A micrometer is a unit of microscopic measurement convenient for describing cellular dimensions; one millionth of a meter, 10**E-6 meter (about 1/25,000th of an inch). Micrometer has replaced the now obsolete term "micron."
Microneurography
Microneurography is a procedure in which a small needle (the size of an acupuncture needle) is placed in an accessible nerve just belowthe knee. With the needle, the nerve signals traveling from the brain to the blood vessels can be measured directly.
Micronutrient
A micronutrient is an organic compound such as a vitamin or element, essential in minute amounts to the growth and health of an organism.
Microorganism
A microorganism, or microbe, is any organism too small to be seen by the naked eye. Bacteria, viruses, protozoa, and some fungi and algae are microorganisms.
Microspectrophotometry
Microspectrophotometry is a technique for characterizing and quantitating nucleoproteins in single cells or cell organelles by their natural light absorption spectra or after reaction with a certain chemical such as the Feulgen stain that is used to make DNA visible.
Microvasculature
Microvasculature refers to very small blood vessels.
Microwave
A microwave is any electromagnetic radiation having a wavelength in the approximate range from one millimeter to one meter, the region between infrared and short-wave radio wavelengths.
Midline
The midline is an imaginary vertical line that divides the body of a bilaterally symmetrical animal into equal left and right sides.
MIH
Mechanical Interface Hardware
Mil
Military
Milliequivalents
An equivalent is equal to the product of the moles and valence of an ion; one milliequivalent is equal to 1/1000 Eq. Concentrations are often expressed in terms of milliequivalents per liter of solution. For singly charged (univalent) ions, 1 mEq is the same as 1 millimole (mmole).
Millirad
A millirad is one-thousandth of a rad. A rad is a unit of measurement denoting the absorbed dose of ionizing radiation.
Millirem
A millirem is one-thousandth of a roentgen, which is a unit of radiation.
min
Minute
MIN
Minor Hardware
Mineral
Minerals (in nutrition) are usually referred to by the name of a metal, nonmetal, radical or phosphate rather than by the name of the compound of which it is a part, and that is ingested as a compound, such as sodium chloride (table salt), rather than as a free element. Mineral also refers to the main chemical compound in bone, deposited as minute crystals in a netlike matrix of fibers.
Mineral balance
Bone is composed of several types of minerals, primarily calcium. The measure of the mineral balance, the difference between mineral absorption from the blood and mineral release into the blood from the bones, can be used to determine the health of the bones.
Mineral metabolism
Mineral metabolism involves the bodies' chemical utilization of minerals, any homogeneous inorganic material found in the earth's crust, for the liberation of energy in some form or for the development of more complex substances.
Mineralization
Mineralization is the addition of mineral matter to the body.
Mineralogical
Mineralogy is the scientific study of minerals, which are any naturally occurring, homogeneous inorganic substances having a definite chemical composition and characteristic crystalline structure, color and hardness.
Mineralogy
Mineralogy is the scientific study of minerals, which are any naturally occurring, homogeneous inorganic substances having a definite chemical composition and characteristic crystalline structure, color and hardness.
Minimum Essential Medium (MEM)
Minimum Essential Medium (MEM) is a tissue culture medium that provides the minimum nutrients necessary for cell growth. This media can accomodate various cell lines by adding different reagents (i.e., fetal bovine serum, sodium pyruvate, non-essential amino acids and antibiotics) as required by each line.
Minute ventilation
Minute ventilation is the volume of air that passes into and out of the lungs each minute.
Minute volume
Minute volume is the volume of any fluid moved per minute; e.g. the cardiac output or the respiratory minute volume.
MIO
Mission Integration Office
MIO
Management Information Office
MIP
Mission Integration Panel
MIPS
Marshall Interactive Planning System
MIPS
Million Instructions Per Second
MIS
Management Information System
Mission Elapsed Time (MET)
Mission Elapsed Time (MET) is a measurement of the time that has passed since launch of a space flight mission or other such endeavor.
Mitigate
To mitigate is to make less severe or intense; to modulate.
Mitigation
Mitigation is the act of making less severe or intense.
Mitochondria
Mitochondria are subcellular organelles found in eukaryotes which are between 0.2-0.5 micrometers in length. It consists of a double membrane surrounding a matrix, with the inner membrane folded into finger-like projections called cristae. The walls of these cristae are the site of energy production for the cell, because of this the mitochondria are called the powerhouse of the cell. The mitochondria are found in large numbers in cells with high energy needs. The mitochondria are self replicating and contain DNA by which they control synthesis of their own proteins.
Mitogen
A mitogen is any substance that causes cells to begin division (mitosis).
MITS
Mission Integration Training/Simulation
MIUL
Material Identification and Usage List
ML
Minilab
MLA
Multispectral Linear Array
MLI
Multilayer Insulation
MLS
Microwave Limb Sounder
mm
Millimeters
MM
Mission Manager (MATSCO, Mountain. View)
MM
Mass Memory
MMC
Mount Manual Control
MMD
Mobile (Servicing Center) Maintenance Depot
MMFR
Maximum Mid-Expiratory Flow Volume
MMFR
Maximum Mid-Expiratory Flow Volume
MMH
Monomethyl Hydrazine
mmHg
Millimeters of mercury.
MML
Man-Tended Multipurpose Laboratory
MMPF
Microgravity and Materials Processing Facility
MMS
Maintenance Management System
MMU
Manned Maneuvering Unit
mo
Month
MOA
Memorandum of Agreement
Mobility
Mobility is the quality of being able to move readily, quickly, and freely.
Mock-up
A mock-up is a scale model of a spacecraft, such as the Shuttle or Spacelab, that is used for training and planning purposes.
MOCR
Mission Operations Control Room
Modal
Modal means of or relating to, or characteristic of a mode, which is any numerous patterns of wave motions, as of acoustic waves.
MODIS
Moderate Resolution Imaging Spectrometer
MOI
Moment of Inertia
Molecular
Molecular refers to a small particle composed of two or more atoms. Molecules are a stable configuration of atomic nuclei and electrons bound together by electrostatic and electromagnetic forces. Molecules have characteristic physical and chemical properties, different from the atoms they are composed of.
MOM
Orbiter Multiplexer/Demultiplexer
Moment
A moment is the rotation produced in a body when a force is applied.
Monoamine oxidase (MAO)
Monoamine oxidase (MAO) is an enzyme that catalyzes the oxidation of a large variety of monoamines, including epinephrine, norepinephrine, and serotonin; it is found in most tissues, particularly the liver and nervous system. Drugs that act as inhibitors of this enzyme are widely used in the treatment of depression.
Monoclonal antibody
A monoclonal antibody is an antibody that is produced artificially from a single cell clone and therefore consists of a single type of immunoglobulin. For example, monoclonal antibodies are produced by fusing antibody-forming lymphocytes from mouse spleen with mouse myeloma cells. The resulting hybrid cells, called hybridoma, multiply rapidly (like cancer cells) and produce the same antibody as their parents.
Monocular
Monocular means having only one eye, or with one eye only, as monocular vision. Monocular also means adapted to be used with only one eye at a time, as a monocular microscope.
Monocyte
A monocyte is the largest form of white blood cell with a kidney-shaped nucleus; its function is the ingestion of foreign particles such as bacteria and tissue debris. Monocytes belong to the group of phagocytes.
Monoenergetic
Monoenergetic means containing only one energy source (i.e., physical or chemical energy).
Monolayer
A monolayer is a single layer of cells growing on a cell culture surface.
Mononuclear
Mononuclear means having one nucleus, particularly a blood cell, such as a monocyte or lymphocyte.
Monosynaptic
A monosynaptic reflex refers to a reflex that is activated by nerve signals traveling through only one synapse. A synapse is the junction between adjacent nerve cells that permits the direct passage of ions.
Monovalent
Monovalent means univalent, having the combining power of an atom of hydrogen, denoting a valence of one, or pertaining to a specific antiserum.
MOP
Maximum Operating Pressure
MORD
Mission Operations Requirements Document
Morey-Holton protocol.
The Morey-Holton protocol requires the hindlimbs of rodents to be elevated to avoid weightbearing by the hindquarters and produce a 30-degree head-down tilt, which results in a cephalad-fluid shift.
Morphogenesis
Morphogenesis is a change in the shape or structure of an organism through growth and differentiation.
Morphological
Morphological means relating to structure or anatomy.
Morphology
Morphology is the study of the form and structure of organisms, especially their external form.
Motility
Motility is the power to move spontaneously.
Motor
Motor means pertaining to muscle movement or to neurological control of muscle movement.
Motor control
Motor control refers to muscle tone and coordination.
Motor cortex
The motor cortex is the region of the cerebral cortex that is responsible for initiating nerve impulses that enable organisms to voluntarily move the muscles of the body. It is possible to map out the cortex to show which of its areas is responsible for which particular part of the body.
Motor nerves
Motor nerves are the nerves that transmit nerve impulses from the central nervous system to an organ (such as a muscle or gland), thereby initiating a physiological response (e.g. a muscle contraction).
Motor plasticity
Motor plasticity refers to the capability of that which imparts movement, i.e., the muscles, to be formed or molded, i.e. the quality of being plastic.
Motor units
Motor units are different muscle parts constituting the muscle; each unit can be stimulated independently.
MOU
Memorandum of Understanding
MP
Maintenance Platform
MPAC
Multipurpose Application Console
MPAD
Mission Planning and Analysis Division
MPD
Magnetic Plasma Dynamic
MPE
Mission Peculiar Equipment
MPG
Multiple Point Ground
mph
Miles per Hour
MPM
Module & Pallet Mode
MPP
Material Processing Platform
MPS
Materials Processing System
MPSE
Mission Peculiar Support Equipment
MPSR
Materials Price Support Request
MR
Materials Request
MR&R
Material Review and Repair
MRB
Material Review Board
MRD
Mission Requirements Document
MRDB
Mission Requirements Data Base
MRMS
Mobile Remote Manipulator System
MROFIE
Mission Requirements on Spacelab Facilities Instruments & Equipment
MRS
Mobile Remote Servicer
MS
Mail Stop
MS
Margin of Safety
MS
Mission Specialist
MSB
Most Significant Bit
MSB
Mesocotyl Suppression Box
MSBLS
Microwave Scan Beam Landing System
MSC
Mobile Servicing Center
MSD
Medical Sciences Division
MSDP
Mission Station Distribution Panel
MSDR
Material Science Double Rack
MSDS
Material Safety Data Sheets
MSE
Measuring & Stimuli Unit
MSFC
George C. Marshall Space Flight Center
MSGS
Messages
MSI
Man System Integration
MSK
Manual Select Keyboard
MSOB
Manned Space Operations Building
MSRD
Mission Science Requirements Document
MSS
Manufacturers Standardization Society
MSS
Multispectral Scanner
MSS
Mission Specific Software
MSSE
Mission Specialists Station Equipment
MT
Mobile Transporter
MTA
Man-Tended Approach
MTC
Man-Tended Capability
MTL
Materials Technology Laboratory
MTO
Man-Tended Option
MTRC
Man-Tended Reference Configuration
MTU
Master Time Unit
MTU
Master Training Unit
MTV
Monitor Television
MUA
Materials Usage Agreement
Mucoid
Mucoid means resembling mucous.
MUL
Material Usage List
Multifidus
The multifidus is a muscle that rotates the vertebral column.
Multiple Docking Adapter
The Multiple Docking Adapter is a module that joins the Command Module to the Skylab Orbital Workshop during docking; it also serves as a portal into the Orbital Workshop from the Command Module.
Mumps
Mumps is an acute infectious and contagious disease caused by Paramyxovirus and characterized by inflammation and swelling of the parotid gland, sometimes of other salivary glands and occasionally by inflammation of the testis, ovary, pancreas or meninges.
MUMPS
Massachusetts General Hospital Utility Multi Programming System
Muscle contraction
A muscle contraction is a shortening or tightening of a muscle.
Muscle fiber type
Muscle fiber type refers to the type of muscle fiber contraction, broadly categorized as slow, intermediate, or fast. Muscle fiber types are usually identified by staining with ATPase or by measuring the reactivity of myosin.
Muscle fibers
A muscle consists of sheets or bundles of cells called muscle fibers. The muscle fibers are capable of contraction, which produces movement or tension in the body. The muscle fibers are mainly composed of the proteins, actin and myosin.
Muscle physiology
Muscle physiology is the study of the function of muscle. Skeletal muscles, the prime focus of space-related muscle physiology research, seem to be most affected by microgravity.
Muscular system
The muscular system refers to a collection of muscles, all of which have the ability to contract, producing movement or force.
Musculoskeletal
Musculoskeletal refers to the system of muscles and bones in vertebrates.
Musculus spinalis capitus
Musculus spinalis capitus is a spinal muscle of the head.
Musculus spinalis cervicus
Musculus spinalis cervicus is a spinal muscle of the neck.
Musculus spinalis thoracis
Musculus spinalis thoracis is a spinal muscle of the thorax.
MUSS
Module Utility Support Structure
Mutation
A mutation is a change in the parent DNA sequence or genetic code caused by exposure to chemicals and radiation.
MUX
Multiplex or Multiplexer
MVAK
Module Vertical Access Kit
MVT
Mission Verification Test
Mycological
Mycological is relating to the study of fungi.
Mycoplasma
Mycoplasma refers to members of the genus Mycoplasma. Mycoplasmas are aerobic to facultatively anaerobic bacteria containing Gram-negative cells, which do not possess a true cell wall.
Mycoplasma pneumoniae
Mycoplasma pneumoniae is a species that causes primary atypical pneumonia in man.
Mycotic
Mycotic means pertaining to a disease caused by a fungus.
Mylar
Mylar is a tough film of polyester, usually used in recording tapes and electrical insulation.
Myocardial
Myocardial means pertaining to the heart's muscle tissue.
Myocardial infarction
Myocardial infarction is necrosis, or tissue death, of a portion of cardiac muscle caused by obstruction in a coronary artery; a heart attack.
Myocardial ischemia
Myocardial ischemia is inadequate circulation of blood to the myocardium, usually as a result of coronary artery disease.
Myocardial mass index
Myocardial mass index is the mass of the heart's muscle tissue, with body size taken into account.
Myocardium
The myocardium is the the muscular wall of the heart; specifically the middle of the three layers forming the wall of the heart. It is composed of cardiac muscle and forms the greater part of the heart wall. The thickness reflects the magnitude of the pressure generated in the heart during contraction; the myocardium is thickest around the left ventricle which does most of the work in the heart.
Myocyte
A myocyte is a contractile cell, especially a muscle cell.
Myofibril
Myofibrils are very small fibers that run through each muscle fiber. The myofibrils have alternate light and dark bands, which contain protein filaments responsible for the muscle's contractile ability and give the muscle its typical striped appearance under the microscope.
Myoglobin
Myoglobin is a globular protein occurring widely in muscle tissue as an oxygen carrier. It supplies oxygen to the muscle during strenuous exercise, when the muscle oxygen demands out paces the supply from the blood.
Myopathy
Myopathy is a term denoting any disease of the muscles. The myopathies are usually subdivided into those that are inherited (like muscular dystrophy) and those that are acquired. All are typified by weakness and wasting of the muscles in the upper parts of the arms and legs.
Myosin
Myosin is a contractile protein that interacts with the protein actin to bring about contraction of muscle or cell movement. Myosin is present in the myofibrils of the muscles.
Myotonometer
A myotonometer is a device which can measure and record muscle tone.
N
Newtons
N-telopeptide
N-telopeptide is a collagen metabolite which is released into the circulation as collagen is degraded during bone resorption. Once in circulation, it is cleared by the kidneys and excreted in the urine. This collagen metabolites are neither metabolized nor absorbed from the diet; and thus, its excretion directly reflects the rate of bone resorption.
N/A
Not Applicable
N/C
Numerical Control
N/m2
Newtons per Square Meter
NAD synthetase
NAD synthetase is a key enzyme in the formation nicotinamide adenine dinucleotide (NAD) biosynthesis. NAD serves as a respiratory enzyme that alternates between oxidation and reduction states with the hydrogen atom. NAD synthetase is target for structure based design of antibiotics.
Nadir
The nadir is the lowest point.
NAS
National Aerodynamics Simulator
NASA
National Aeronautics and Space Administration
NASA 2
NASA 2 is the name of the second long-duration stay of an American astronaut on board the Russian Space Station Mir. The NASA 2 increment started with the docking of the American Space Shuttle with the Mir station during STS-76 on March 22, 1996 and ended with the docking of the Shuttle Atlantis with Mir during the STS-79 mission, on September 18, 1996.
NASA 3
NASA 3 is the name of the third long-duration mission of an American astronaut on board the Russian Space Station Mir. The NASA 3 increment started with the docking of the American Space Shuttle with the Mir during the STS-79 mission, on September 18, 1996, and will end with the docking of STS-81 early in 1997.
NASCOM
National Council of Radiation Protection and Measurement
NASDA
National Space Development Agency (Japanese Space Agency)
NASnet
Numerical Aerodynamic Simulator Network
Natriuresis
Natriuresis is the excretion of sodium in the urine.
Natriuretic factors
Natriuretic factors are hormone-like substances present in the two atrial walls of the heart (especially numerous in the right atria). Natriuretic factors can cause a three to ten times increase in renal (kidney) excretion of sodium. Consequent to the loss of sodium is a slight decrease in the extracellular fluid volume and blood volume. Although the exact mechanism of action is unclear, it is believed that these factors play a role in the regulation of blood volume.
Natural killer cell (NK cell)
A natural killer cell is a specific type of lymphocyte (white blood cell) which kills "target" (tumor or virus-infected) cells without involving antibodies. The mechanism of their killing activity is not yet clear, but interferon seems to play a role.
Nausea
Nausea is a feeling of sickness to the stomach that precedes vomitting.
NB
Navigation Base
NBS
National Bureau of Standards
NCC
Network Control Center
NCD
Number Column Density
NCR
Nonconformance Report
NDE
Nondestructive Evaluation
NDT
Nondestructive Test
NEC
National Electrical Code
Necrosis
Necrosis is the death of cells in an organ or tissue, which can be caused by a variety of chemicals and toxic substances.
Negative energy balance
A negative energy balance occurs when the body expends more energy (measured as calories) than it receives through the consumption of food.
Negative pressure
Negative pressure is the pressure produced by suction.
NEMA
National Electrical Manufacturers Association
Nematode
Nematodes are invertebrates comprising the parasitic roundworms. They are characterized by a smooth narrow cylindrical unsegmented body tapered at both ends. They shed their tough outer cuticle four times during life to allow growth. The microscopic free-living forms are found in all parts of the world, where they play an important role in the destruction and recycling of organic matter. The parasitic nematodes are much larger and some of them can cause serious diseases in man.
Neoplasm
A neoplasm is any abnormal growth of new tissue, benign or malignant.
Nephrotic syndrome
Nephrotic syndrome is characterized by generalized edema, albumin in the urine and low serum albumin. This condition is caused by increased permeability of the glomerular capillary basement membranes.
Nervous system
The nervous system is the vast network of cells specialized to carry information (in the form of nerve impulses) to and from all parts of the body in order to bring about bodily activity. In vertebrates, the brain and spinal cord together form the central nervous system. The remaining nervous tissue is known as the peripheral nervous system and includes the autonomic nervous system, which is itself divided into the sympathetic and parasympathetic nervous systems. The basic functional unit of the nervous system is the neuron (nerve cell).
Neural
Neural means pertaining to the nervous system.
Neuraminidase
Neuraminidase is an enzyme that cleaves terminal acylneuraminic residues from oligosaccharides, glycoproteins, or glycolipids; present as a surface antigen in myxoviruses. It is also used in histochemistry to selectively remove sialomucins as from bronchial mucous glands and the small intestine.
Neuroendocrine system
The neuroendocrine system is a system of dual control of certain activities of the body by means of both nerves (neuro-) and circulating hormones (endocrine).
Neuroglia
Neuroglia refers to glial cells or glia cells of the nervous system that support the neurons (nerve cells). They form insulating sheets of tissue around the neurons (called myelin), preventing impulses from traveling between adjacent neurons. Other functions include providing nutrition and controlling the fluids surrounding the neurons.
Neurological
Neurological means of or relating to the nerves.
Neurology
Neurology is the branch of medical science concerned with the nervous system and its disorders.
Neuromuscular
Neuromuscular means of or relating to nerves and the muscles they stimulate.
Neuromuscular junction
The neuromuscular junction is the point where a muscle fiber comes into contact with motor neurons carrying nerve impulses from the central nervous system. The impulses travel from the neurons to the muscle fiber by means of a neurotransmitter to overcome the small gap between the two nerve cells.
Neuromuscular physiology
Neuromuscular physiology is the research area that focuses on studying the nerves and the muscles they stimulate.
Neuromuscular system
The neuromuscular system consists of the nerves and the muscles they stimulate.
Neuron
A neuron is a nerve cell, one of the basic functional units of the nervous system; it is specialized to transmit electrical nerve impulses and so carry information from one part of the body to another.
Neuropharmacological
Neuropharmacological means relating to drugs that exert effects on nerve tissue or the transmission of nerve impulses.
Neurophysiology
Neurophysiology is the study of the physiology of the nervous system.
Neuropil
The neuropil is the complex, feltlike net of axonal, dendritic and glial arborizations that forms the bulk of the central nervous system’s gray matter, and in which the nerve cell bodies lie embedded.
Neuroscience
Neuroscience is any one of the various branches of science concerned with growth, development and function of the nervous system.
Neurosensory
Neurosensory means of or relating to the sensory aspects of the nerves and nervous system, such as the ability of the nerves to sense stimuli from the body itself or from the external environment.
Neurospora
Neurospora is a genus of fungi grown in cultures that is used in genetic and cellular biochemistry research.
Neurotoxicant
A neurotoxin is any substance that is poisonous to the nervous system.
Neurovestibular
Neurovestibular relates to the interaction between the brain and the vestibular organ, which is located in the inner ear.
Neutron diffraction
Neutron diffraction is a method used to determine the molecular structure of a material by passing a neutron beam through the sample and capturing the diffraction pattern.
Neutrophil
A neutrophil is a white blood cell distinguished by a lobed nucleus and granular cytoplasm that has the capability of ingesting and killing bacteria by releasing various substances, such as lysozyme (antibacterial enzyme) and oxidizing agents.
Neutrophilia
Neutrophilia is an increase in the number of neutrophils (a type of white blood cell) in the blood.
NFE
NASA Furnished Equipment
NFPA
National Fire Protection Association
NGP
Neutral Gas Plume
NGT
NASA Ground Terminal
NHA
Next Higher Assembly
NHB
NASA Handbook
NIAMDD
National Institute of Arthritis, Metabolism and Digestive Diseases
Nickel
Nickel is a silver-white hard malleable ductile metallic element capable of a high polish and resistant to corrosion. It is used chiefly in alloys and as a catalyst.
NIDDK
National Institute of Diabetes, Digestive and Kidney Diseases
Nitrogen (N2)
Nitrogen is a gaseous element found in air (78% of air volume); it is an essential component of proteins and nucleic acids in living organisms.
Nitrogen balance
Nitrogen balance is the measure of the difference between nitrogen absorption and nitrogen release in the body.
Nitrogen tetroxide (N2O4)
Nitrogen tetroxide (N2O4) is a poisonous volatile liquid which gives off a brownish irritant fume.
Nitrogen-15 isotope
The nitrogen-15 isotope is a nonradioactive biological tracer that can be measured in urine and saliva samples and used to study protein metabolism.
NLA
Next Lower Assembly
NM
Nautical Miles
NMI
NASA Management Instruction
nmi
Nautical Miles
No
Number
NOAA
National Oceanic and Atmospheric Administration
Nomex
Nomex is a material that provides outstanding heat and flame resistance while having good textile properties. Applications include protective clothing, hot-gas filters, industrial coated fabrics, ironing- or pressing-machine parts, felt scrims, and reinforcement for rubberized belting and hoses. In paper or pressboard form Nomex is used for electrical insulation.
Non-antigravity
The term non-antigravity refers to muscles (or bones) that are not affected by the absence (or pressure) of gravity, such as the respiratory diaphragm muscle.
Noninvasive
Noninvasive describes diagnostic procedures which do not involve the insertion of devices into the body or require penetration of the skin. Common noninvasive techniques are ultrasound or EKG.
Nonspasmodic
Nonspasmodic means not having the character of a spasm or convulsion.
Nonvascularity
Nonvascularity is used to describe a region where blood vessels are absent and blood perfusion does not occur. The vascular system is another name for the blood circulation system of the human body. Nonvascularity describes the absence of the vascular system.
Nonvolatile
Nonvolatile means not vaporizing readily.
Norepinephrine
Norepinephrine, also known as noradrenaline, is a hormone produced by the adrenal glands and also secreted from nerve endings in the sympathetic nervous system as a chemical transmitter of nerve impulses. Many of its general actions are similar to those of adrenalin, but it is more concencerned with maintaining normal body activity than preparing the body for emergencies.
Normoxia
Normoxia is a state in which the partial pressure of oxygen in the inspired gas is equal to that of air at sea level, about 150 mm Hg.
Normoxic
Normoxic is a state in which the partial pressure of oxygen in the inspired gas is equal to that of air at sea level, about 150 mmHg.
Noxious
Noxious injurious or harmful to health.
NR
Non-Recurring
NR-T
Non-Real Time
NRC
Nuclear Regulatory Commission
NRL
Naval Research Laboratory
NRT
Near Real Time
NRZ-L
No Return to Zero-Level Defined
ns
Nanoseconds
NS2
System Safety Branch
NSBRI
National Space Biomedical Research Institute
NSF
National Science Foundation
NSI
NASA Science Internet
NSI
Northrup Services, Inc.
NSI-ATC
Northrup Services, Incorporated - Applied Technology Center
NSN
National Stock Number
NSPAR
Nonstandard Part Approval Request
NSTL
Nation Space Technology Laboratory
NSTS
National Space Transportation System
NTI
Non-Terrestrial Intelligence
NTO
Nitrogen Tetroxide
Nucleation
Nucleation is the coalescence of molecules or small particles that is the beginning of a crystal or similar small deposit. For metals, nucleation is the beginning of the solid state structure of the alloy (mixture of metal elements), the forming of a pattern when the rest of metals are in the molten-liquid state. Around a "nucleus," the melted alloy solidifies more rapidly, possibly changing its structure (with less favorable characteristics), or forming bubbles, etc. As a basic rule investigators like to avoid nucleation during solidification. In microgravity, the occurrence of nucleation is reduced and the structure of the resolidified metal is more even.
Nucleic acid
A nucleic acid is either of two organic acids, DNA or RNA, present in the nucleus and in some cases the cytoplasm of all living cells. Their main functions are in heredity and protein synthesis.
Nucleosome core particle
Nucleosome core particle is a localized aggregation histone and DNA that is evident when chromatin is in the uncondensed stage.
Nucleus
In neuroanatomy, the nucleus is a group of nerve cells in the brain or spinal cord that can be demarcated from neighboring groups on the basis of either differences in cell type or the presence of a surrounding zone of nerve fibers or cell poor neuropil.
Nullify
Nullify means to neutralize or to equalize a given stimuli which results in a neutralization of the impulse (thereby the sum of the given stimuli and the reaction must be zero).
Nutational
Nutational is the oscillatory movement of the axis of a rotating body; wobble.
Nutrient
A nutrient is a nourishing substance, especially a nourishing ingredient in a food.
Nutrition
Nutrition is the process of nourishment, by which organisms obtain energy (in the form of food) for growth, maintenance, and repair.
Nystagmus
Nystagmus is a rhythmical oscillation of the eyeball, either pendulum-like or jerky. A variety of causes for nystagmus are known. In space-related research, the caloric nystagmus (caused by hot or cold water in the ear), the optokinetic nystagmus (triggered by looking at a rotating dome), and the vestibular nystagmus (when a rotation of the body stops abruptly) are of special interest.
Nystagmus dumping
Nystagmus dumping is a phenomenon associated with postrotational nystagmus, which occurs after rotation about the vertical axis. The "dumping" effect results from tilting the head during postrotational nystagmus and is characterized by a decrease in the gain of the response and a shortening of the nystagmus decay time constant.
O
Overhead
O&C
Operations and Checkout
O&IA
Operations and Integration Agreement
O&M
Operations and Maintenance
O-B
Onboard
O-D
On Dock
O/A
Operations/Administrative
O2
Oxygen
OA
Overall
OA
Phase A
OAFD
Orbiter AFT Flight Deck
OAMS
On-Orbit Alignment Measurement System
OAST
Office of Aeronautics and Space Technology (NASA)
OB
Phase B
OBS
Operational Bioinstrumentation System
Occipital
The occipital is a region of the scull and the brain located at the lower back portion of the head.
Occlusive cuff
An occlusive cuff is a cuff which closes around the arm or other body part, usually in the location of a major blood vessel for the purposes of measuring blood pressure.
Occult
Occult refers to something being obscure, hidden from observation, or difficult to understand.
OCI
Ocean Color Instrument
OCP
Office of Commercial Program (NASA)
Ocular counter-rolling
Ocular counter-rolling is movement of the eye (ocular torsion) produced by head tilt. It occurs when the head is tilted to either side and the eyes roll in the opposite direction to compensate and maintain focus on the visual target. If proper technique is used, the amount of ocular counter-rolling can be a specific and valid measure of otolith function. The ocular counter-rolling test is used by researchers to determine whether prolonged lack of stimulation of the otolith apparatus (which occurs in weightlessness) alters its basic sensitivity.
Ocular torsion
Ocular torsion is a twisting or turning motion of the eye which results from the combination of gravity and inertial forces during linear acceleration or head tilt.
Oculogyral
Oculogyral refers to rotation of the eyes; oculo = "of the eyes", gyral = "to revolve or rotate"
Oculomotor
Oculomotor means relating to or causing movements of the eyeball.
Oculomotor nerve
The oculomotor nerve originates in the midbrain and supplies all but two of the extrinsic muscles of the eye.
Oculomotor range (EOM)
The oculomotor range (EOM) is defined as the area in which any target can be tracked by eye-movement only. Targets outside of the EOM are defined as targets which require additional head movement to be tracked.
Oculomotor system
The oculomotor system refers to all body parts which are involved in tracking and gazing at visual targets by eye movements.
ODS
Onboard Data System
OFCE
Operations Flight Crew Equipment
OFT
Orbital Flight Test
OFTP
Orbital Flight Test Pallet
OHA
Operation Hazard Analysis
OHMP
Operations Handling & Maintenance Procedures
OIA
Orbiter Interface Adapter
OIR
Open Item Review
OIS
Operational Intercom System
OIT
Orbiter Integrated Test
OJT
On-the-Job Training
OLEP
Offline Equipment Preparation Area
OLF
Orbiter Landing Facility
Olfactory complex
The olfactory complex refers to all body-parts involved in the sense of smell or the process of detecting smells. This is achieved by receptors in olfactory organs, such as the nose, that are sensitive to air-borne or water-borne chemicals. Stimulation of these receptors results in the transmission of information to the brain via the olfactory nerve.
Oligemia
Oligemia (hypovolemia) is a deficiency in the amount of blood in the body.
Oligonucleotide
Oligonucleotide is a compound made up of the condensation of a small number of nucleotides.
OLSP
Offline Specimen Preparation Area
OM
Orbital Module
OMB
Office of Management and Budget
OMCF
Orbiter Maintenance Checkout Facility
OMD
Operations and Maintenance Documentation
OMD
Orbiter Mid Deck
OMI
Operations and Maintenance Instructions
OMIS
Operational Management Information System
OMM
Operations and Maintenance Manual
Omnivorous
Omnivorous means eating all kinds of foods indiscriminately, or eating both animal and plant foods.
OMP
Operations and Maintenance Plan
OMRSD
O&M Requirements and Specifications Documentation
OMS
Operations Management System
OMV
Orbital Maneuvering Vehicle
ON-BRD
On-Board
Ontogenesis
Ontogenesis refers to the entire development of an individual organism from fertilization to completion of life history.
OOS
On-Orbit Station
OOSDP
On-Orbit Station Distribution Panel
OP
Operations Panel
OP Amp
Operational Amplifier
OP REQ
Operational Requirements
Operational point
The operational point in baroreceptor studies is the interval between R waves at zero neck pressure during an experiment.
OPF
Orbiter Processing Facility
Ophthalmic
Ophthalmic means administration of medication by instillation of a cream ointment, or liquid drops in the conjuctival sac of the eye.
Ophthalmology
Ophthalmology is the medical specialty concerned with the eye, its diseases, and refractive errors.
Ophthalmoscopy
Ophthalmoscopy is the examination of the interior of the eye, especially the retina, with an ophthalmoscope, an instrument with a mirror that is perforated in the center.
OPM1-1
A Microcomputer System
OPNS
Operations
Opportunistic
Opportunistic describes an organism that can become infectious when the host's resistance is impaired.
OPR
Office of Primary Responsibility
OPS
Operations
Optic tectum
The optic tectum is the part of the brain that plays a key role in localizing auditory and visual targets.
Optical
Optical means pertaining to or using light; it also describes something designed to assist sight.
Optokinetic
Optokinetic refers to the occurrence of intermittent rotation of the eye when the subject looks at moving objects. In other words, when the visual scene continually moves before the eyes, such as when a person is riding in a car or turning around, the eyes fix on one highlight after another in the visual field, jumping from one to the next at a rate of two to three jumps per second. The jumps are called saccades and the movements are called optokinetic movements.
Optokinetic nystagmus (OKN)
Optokinetic Nystagmus (OKN) occurs when the nystagmus (movement) of the eye is induced by looking at a moving visual stimuli.
Optokinetic reflex
The optokinetic reflex is a reflexive eye movement that consists of the intermittent rotation of the eye when a subject looks at moving objects.
ORB
Orbiter
ORB
Orbit location
ORB 1-G
Orbiter One-G Trainer
Organelle
An organelle is any part of a cell that has a unique structural, functional or anatomical role. On a smaller scale, organelles are similar to the organs in your body - they are, in effect, the organs of a cell.
Organic
Organic means of or originating from carbon compounds.
Organic acid
An organic acid is an acid made up of molecules containing organic radicals (e.g., acetic acid and citric acid, which contain the ionizable -COOH group).
ORI
Operational Readiness Inspection
ORR
Operations Readiness Review
Orthogonal
Orthogonal means pertaining to or composed of right angles.
Orthostatic
Orthostatic means pertaining to the upright position of the body; the term is used when describing this position or a condition associated with it. Orthostatic hypotension, for example, is low blood pressure found in some people when they stand upright.
Orthostatic hypotension
Orthostatic hypotension is a temporary and short-lived condition of low blood pressure, sometimes occurring when a person stands or sits upright from a sitting or recumbent position; it can result in light-headedness or fainting.
Orthostatic intolerance
Orthostatic intolerance is a condition of lightheadedness, possibly leading to fainting, that occurs when an upright position is assumed; it is caused by low blood pressure and an inadequate supply of blood to the brain. Astronauts often experience temporary orthostatic intolerance when remaining upright after returning from stays in space, because their blood volume is reduced in microgravity and the pull of gravity does not allow sufficient blood flow to reach the head.
ORU
Orbital Replaceable Unit
Os calcis
The os calcis is the largest bone in the foot. It is commonly referred to as the heel bone. In medical terminology, it is also referred to as the calcaneus.
OS8
Operating System 8 for PDP-8 Computers
Oscillate
To oscillate is to move back and forth between two points.
Oscillation
An oscillation, as it applies to microgravity experiments, is a vibration. However, oscillations can refer to any steady back and forth movements.
Oscillator
An oscillator is any device that produces a to and fro movement; it may also be defined as an electric circuit designed to generate alternating current at a particular frequency.
Oscillometer
An oscillometer is a device which measures arterial blood pressure; it consists of a recording apparatus that can register pulsations in a lightly inflated blood pressure cuff around the forearm.
Oscillometry
Oscillometry is the measure of arterial blood pressure by recording the pulsation in the lower arm with an oscillometer while a cuff is inflated over the upper arm. An oscillometer consists of a recording apparatus that can register pulsations in a lightly inflated blood pressure cuff around the forearm.
Oscillopsia
Oscillopsia is the subjective sensation that objects being viewed are moving to and fro, or oscillating.
OSE
Orbital Support Equipment
OSHA
Occupational Safety and Health Act
OSI
Open Systems Interconnect
Osmolality
Osmolality is a property of a solution which measures the concentration of the solute per unit of solvent.
Osmoreceptor
An osmoreceptor is any of the group of structures found in the hypothalamus that respond to changes in the osmotic pressure of the blood.
OSP
Operation Support Plan
OSS
Office of Space Station
OSSA
Office of Space Science and Applications (NASA)
Ossification
Ossification (osteogenesis) is a three-stage process by which bone is formed. The first step is the formation of a mesh of collagen fibers. Next, the body produces a "cement" substance (polysaccharide). Finally, small crystals of calcium salts are deposited into the cement to form bone.
OSTA
Office of Space Terrestrial Application
OSTA
Office of Space Tracking and Data Systems
Osteoblast
An osteoblast is a type of cell that is responsible for the formation of bone.
Osteocalcin
Osteocalcin is a bone matrix protein consisting of 49 amino acids.
Osteoclast
An osteoclast is a large cell with multiple nuclei. It resorbs calcified bone. Osteoclasts are only found when bone is being resorbed and can be seen in small depressions on the bone’s surface.
Osteogenesis
Osteogenesis (ossification) is a three-stage process by which bone is formed. The first step is the formation of a mesh of collagen fibers. Next, the body produces a "cement" substance (polysaccharide). Finally, small crystals of calcium salts are deposited into the cement to form bone.
Osteomyelitis
Osteomyelitis is the inflammation of the bone marrow and adjacent bone.
Osteopenia
Osteopenia is decreased calcification or density of bone, or can also mean reduced bone mass.
Osteoporosis
Osteoporosis is the loss of bony tissue, resulting in bones that become brittle and liable to fracture. Infection, injury and synovitis (inflammation of the membrane surrounding a joint), as well as prolonged exposure to microgravity, can cause osteoporosis.
Otitis media
Otitis media is the inflammation of the middle ear, often preceded by an upper respiratory infection.
Otolith
An otolith (or otoconium) is one of the small particles of calcium carbonate in the saccule or utricle of the inner ear. Pressure of the otoliths on the hair cells of the macula provide sensory inputs about acceleration and gravity.
Otolith-spinal reflex
The otolith-spinal reflex is a postural reflex that prepares the body for the jolt associated with landing after a fall. The otolith organs in the inner ear detect a change in acceleration and send signals through a nerve pathway to the spinal cord. Nerve fibers that control the muscles that maintain posture receive the signals in the spinal cord and act on the muscles.
Otolithic organs
The utricle and the saccule are the otolith organs of the vestibular system. These organs detect linear accelerations and work in conjunction with the semicircular canals to maintain the body's balance.
OTR
Operational Test Requirement
OTV
Orbital Transfer Vehicle
OV
Orbiter Vehicle
Ova
Ova are female gametes; eggs.
OW
Optical Window
OX
Oxidizer
Oxalate
Oxalate is a salt of oxalic acid, an acid found in many plants and vegetables.
Oxidation
Oxidation is the combination of a substance with oxygen. Oxidation can also describe a type of reaction in which the atoms in an element lose electrons and the valence is correspondingly increased.
Oxidation-reduction
Oxidation-reduction refers to any chemical oxidation or reduction reaction, which must comprise both oxidation (to increase the positive charge or valence of an atom by removing electrons) and reduction (to decrease the valence of an atom by adding electrons). In other words, the reactions reverse each other. Oxidation- reduction is often shortened to “redox”.
Oxidative
Oxidative relates to oxidation, which is the combination of a substance with oxygen. Oxidation can also describe a type of reaction in which the atoms in an element lose electrons and the valence is correspondingly increased.
Oxidative enzyme
An oxidative enzyme has the power to oxidize an atom, or to cause it to combine with oxygen or to lose electrons.
Oxygen consumption
Oxygen consumption is the amount of oxygen in milliliters per minute required by the body for normal aerobic metabolism; normally about 250 ml/minute.
Oxygen pulse
Oxygen pulse is the amount of oxygen carried in the blood per beat of the heart.
Oxygen uptake
Oxygen uptake is the amount of oxygen intake used up at the cellular level during exercise. It can be measured by determining the amount of oxygen exhaled as compared to the amount inhaled, or estimated by indirect means.
Oxygen-18
Oxygen-18 is a stable isotope of oxygen that occurs naturally. Oxygen-18 is also referred to as heavy oxygen.
Oxyntic cell
Oxyntic cells (parietal cells) are cells of the gastric glands that secrete hydrochloric acid in the lower region of the stomach.
P
Packet
P&M
Process and Materials
P-aminohippurate (PAH)
Para-aminohippuric acid, or PAH, passes completely through the glomerular membrane. During filtration of blood by the kidneys, only about 1/10 of the original PAH in the plasma remains in the plasma. Therefore, PAH clearance can be used for estimating the flow of plasma through the kidneys.
P-P
Peak-To-Peak
P-QRS-T wave complex
P-QRS-T refers to the distinct points of a complete cardiac cycle seen on the electrocardiogram strip. The P wave is the depolarization or activation of the atria. The QRS wave is the depolarization or activation of the heart’s ventricles. The T wave is the recovery of the ventricles or the depolarization of the ventricles.
P/L
Payload
p/m
Parts per million
P/N
Part Number
PA
Payload Assignment
PAD
Program Approval Document
Pair-fed
Pair-fed means the control group are equally fed as that of the experimental group, to control for weight changes.
Palatable
Palatable means acceptable to the taste.
Pallor
Pallor describes a condition in which the skin color becomes pale; it usually accompanies the onset of a change in physiology (shock, illness, etc.).
Palpation
Palpation is a technique used in physical examinations in which the examiner feels the texture, size, consistency, and location of a certain part of the body with the hands.
PAM
Pulse Amplitude Modulated
Pancreas
The pancreas is a gland about 15 cm long, that lies behind the stomach. One end touches the curve of the duodenum; the other end touches the spleen. It is composed of clusters of cells which are involved in the digestive process. The pancreas is also the gland that produces insulin.
PAO
Public Affairs Officer
PAP
Product Assurance Plan
Papular
Papular means pertaining to or resembling papules, which are small, solid, raised skin lesions less than one centimeter in diameter.
Parainfluenza virus
Parainfluenza virus is a member of the genus Paramyxovirus. Parainfluenza can cause acute laryngotracheitis and croup in children and respiratory infections in adults.
Paramecium
A paramecium is an aquatic, oval-shaped single-celled microscopic organism that moves by means of hair-like projections called cilia. Paramecia are members of the Protozoan family, a group of the most primitive forms of animal life.
Parasite
A parasite is an organism that lives on or in and draws nourishment from another organism.
Parasternal
Parasternal means alongside the sternum.
Parathormone (PTH)
Parathormone (PTH) also called parathyroid hormone, is a peptide hormone formed by the parathyroid glands that raises the serum calcium when administered parenterally (other than via the digestive tract) by causing bone resorption.
Parathyroid hormone (PTH)
Parathyroid hormone (a.k.a. parathormone, PTH) is a hormone, synthesized and released by the parathyroid glands, that controls the distribution of calcium and phosphate in the body.
Parenchyma
Parenchyma is the tissue characteristic of an organ, as distinguished from connective tissue.
Paresthesia
Paresthesia is any subjective sensation experienced as numbness, tingling, or a pins and needles feeling.
Parietal cell
A parietal cell (oxyntic cell) is a cell of the gastric glands that secretes hydrochloric acid in the lower region of the stomach to aid in digestion.
Parotid
Parotid means situated near the ear. It usually refers to the parotid salivary gland.
Parotid gland
The parotid gland is the largest of the salivary glands situated below and in front of the ear, on either side. It discharges through the parotid duct.
PAS
Performance Assessment System
Passive dosimetry
Passive dosimetry is the accurate measurement of radiation doses by means that do not require active subject participation, i.e., a patch worn by crewmembers on their clothing to measure daily radiation doses.
Passive payload
A passive payload on the Space Shuttle, or other space vehicle, does not require any crew time or astronaut interaction to operate, except possibly for the need to be activated, placed in a certain position or shut down.
Pasteurization
Pasteurization is the process of applying heat, usually to milk or cheese, for a specific period of time for the purpose of killing or retarding the development of pathogenic bacteria.
Patella
Patella, also called the knee cap, is a flat triangular bone at the front of the knee joint, having a pointed apex that attaches to the ligamentum patellae.
Pathogen
Pathogens are organisms which cause disease or illness upon entering the body.
Pathogenic
Pathogenic means causing disease or abnormality.
Pathology
Pathology is the study of disease processes with the aim of understanding their nature and causes. This is achieved by observing samples of blood, urine, feces, and diseased tissue obtained from the living patient or from an autopsy, by the use of X-rays and by many other techniques.
Pathophysiological
Pathophysiological pertains to the study of biologic and physical manifestations of disease as they correlate with the underlying abnormalities and physiologic disturbances.
PATS
Physiological Acquisition Telemetry System
Paucity
Paucity means fewness, smallness of number, or scarcity.
PB
Playback
PBI
Pushbutton Indicator
PC
Payload Crew
PCA
Photon Counting Array
PCB
Program Configuration Board
PCC
Property Control Center
PCCR-75
Payload Contamination Control Requirements for STS Induced
PCDT
Particulate Containment Demonstration Test
PCDT
Particulate Contamination Demonstration Test
PCF
Payload Control Facility
PCGU
Protein Crystal Growth Unit
PCIN
Preliminary Change Incorporation Notice
PCM
Pulse Code Modulation
PCM
Pulse Code Modulator
PCMCIA
Personal Computer Memory Card Interface Adapter
PCMMU
CM Master Unit
PCN
Program Control Number
PCO
Program Control Officer
PCOC
Plant Carry-On Container
PCR
Payload Change-out Room
PCRC
Procedure Change Review Committee
PCT
Particulate Containment Test
PCTC
Payload Crew Training Complex
PCU
Payload Checkout Unit
PD
Parkinson's Disease
PDA
Payload Development and Assembly
PDAS
Prelaunch Data Acquisition System
PDAST
Prelaunch Data Acquisition System Tester
PDI
Payload Data Interleaver
PDIR
Physiological Data Interface Rack
PDL
PROGRAM DESCRIPTION LANGUAGE
PDP
Passive Dosimeter Package
PDP 11/3
Programmed Data Processor, Model 11/35
PDR
Preliminary Design Review
PDRD
Program Definition and Requirements Document
PDS
Program Disciplinary Scientist
PE
Project Engineer
Peak oxygen consumption
Peak oxygen consumption refers to the highest value of oxygen consumption measured during an exercise period.
PEDB
Payload Engineering Data Base
Penicillin
Penicillin is any one of a group of antibiotics derived from cultures of species of the fungus penicillium or produced semisynthetically. Administered orally or parenterally, it is used to prevent or treat a wide variety of diseases and infections.
PEP carboxykinase
PEP carboxykinase is an enzyme of the lyase class that catalyzes the conversion of ATP/GTP and oxaloacetate to ADP/GDP, phosphoenolpyruvate, and carbon dioxide.
Pepsin
Pepsin is an enzyme in the stomach that begins the digestion of proteins by splitting them into smaller pieces.
Peptide
A peptide is any group of compounds consisting of two or more amino acids linked by chemical bonding. Peptides in the human body can take the function of hormones (e.g. antidiuretic hormone),can form proteins, or may have functions in the digestive process (and therefore may be found throughout the body - in the digestive tract, blood, cells and tissues).
Perceptual
Perceptual reactions are based on the interpretation of sensory information, using both the data detected by the senses (at the moment) and previous experience.
Perceptual reaction
A perceptual reaction is based on perception, the process by which information about the world, received by the senses, is analyzed and made meaningful.
Perfusion
Perfusion is the passage of fluid through a tissue. It can refer to the passage of blood through the lung tissue to pick up oxygen from the air in the alveoli and the release of carbon dioxide. Or, perfusion can refer to the deliberate introduction of fluid into a tissue, usually by injection into the blood vessels supplying the tissue.
Peridonta6
Peridontal means around a tooth.
Periosteal
Periosteal refers to the periosteum, a layer of dense connective tissue that covers most of the surface of a bone, providing attachment for muscles, tendons and ligaments.
Periosteum
The periosteum is a layer of dense connective tissue that covers most of the surface of a bone, providing attachment for muscles, tendons and ligaments.
Peripheral
Peripheral means relating to or situated near the outer part of the body or organ in relation to the central part or region.
Peripheral blood flow
Peripheral blood flow refers to the blood flow in vessels outside the heart.
Peripheral cardiovascular system
Peripheral cardiovascular system refers to the part of the cardiovascular system (distinguished from the heart and the pulmonary circulation) that supplies blood to all the tissues of the body except the lungs. It includes arteries, arterioles, veins, venules, and capillaries.
Peripheral mononuclear cell
Peripheral mononuclear cells are monocytes and lymphocytes which circulate in the bloodstream.
Peripheral resistance
Peripheral resistance is the hindrance to blood flow in the systemic (nonpulmonary) blood vessels. It is calculated by dividing the pressure drop between the systemic arteries and veins by the blood flow.
Peripheral Venous Pressure (PVP)
Peripheral venous pressure is the blood pressure in the peripheral veins, usually about 4 to 7 mmHg; this pressure is due to the considerable resistance to blood flow in the large veins.
Periphery
The periphery is the outermost part or region within a precise boundary.
Peritonitis
Peritonitis is the inflammation of the sac that lines the abdominal cavity.
Peroxidation
Peroxidation is the act of an enzyme, called peroxidase, catalyzing the oxidation of various substances in the presence of hydrogen peroxide, usually converting to water in the process.
Personal digital assistant (PDA)
A personal digital assistant is a hand-held computer device that may be used to enter, manipulate, and/or display data.
Perturbation
A perturbation is a disturbance or abnormality.
Pertussis
Pertussis means whooping cough, an infectious disease caused by Bordetella pertussis and characterized by recurrent bouts of spasmodic coughing.
PET
Preliminary Evaluation Team
Petechiae
Petechiae are tiny red or purple spots appearing on the skin as the result of minute hemorrhages within the derma or mucosal layers.
Petri dish
A petri dish is a small, shallow circular dish made of thin glass or clear plastic with a loosely fitting, overlapping cover. It is used especially in microbiology for the growing of microorganisms on solid media.
PGOWG
Payloads Ground Operations Working Group
PGS
Power Generation Subsystem
PGU
Plant Growth Unit
PGVU
Plant Growth Vibration Unit
pH
pH indicates the acidity of a substance. A pH below 7 is acid, a pH above 7 is alkaline and a pH of 7 is neutral.
Phage
A phage, also called bacteriophage, is a virus that infects and ultimately destroys bacterial cells. These viruses are normally present in sewage and body products.
Phagocytic cell
Phagocytic cells are white blood cells that protect the body against invading microorganisms by engulfing the organism and then destroying it with digestive enzymes.
Phagocytosis
Phagocytosis is the process whereby materials are surrounded and taken into a cell by invagination of the plasma membrane.
Phalanges
The phalanges, or bones of the fingers (or toes) in vertebrates, number 14 in each hand (foot). A single bone of the finger (or toe) is referred to as a phalanx. There are two phalanges in the thumb and three phalanges in each of the other fingers.
Phalanx
A phalanx is a bone of a finger or toe.
Phantom
A phantom is a device used in radiation biology to estimate the effects of radiation. It simulates the properties of body tissues with respect to deposition of radiation or radioactive material in them.
Pharmaceutical
Pharmaceutical refers to man-made and natural drugs used to treat diseases, disorders, and illnesses.
Pharmacodynamics
Pharmacodynamics is the study of drug action on living organisms.
Pharmacokinetics
Pharmacokinetics is the interactions of a drug with the body and study of the interactions of drugs with the body, with particular emphasis on the time required for interactions to take place. These interactions include absorption, distribution and metabolism of drugs in the body , and their excretion from the body.
Pharmacologic
Pharmacologic means pertaining to the science of drugs, including their composition, uses and effects.
Pharmacology
Pharmacology is the science of the properties of drugs and their affects on the body.
Pharyngeal vault
The pharyngeal vault is the upper portion or roof of the rhinopharynx.
Pharyngitis
Pharyngitis is the inflammation of the mucous membrane and underlying parts of the pharynx.
Phase
Phase refers to a discrete uniform part of a material substance that can be separable from the rest. For example, water can exist in three separate phases: solid (ice), liquid, and vapor.
Phase shift
A phase shift implies a change from the time location associated with a biological rhythm peak or trough. For example, the body temperature of a healthy person is usually lowest (trough) around 9 AM and highest (peak) about 7 PM. A person who works at night and therefore lives a schedule which is basically opposite from the general population, will have the trough body temperature reading in the evening and a peak in the morning - a phase shift of roughly 180 degrees.
Phase-contrast microscope
The phase-contrast microscope is a specially constructed microscope that has a special condenser and objective containing a phase-shifting ring. Small differences in index of refraction are made visible as intensity or contrast differences in the image; it is particularly useful for examining structural details in transparent specimens such as living or unstained cells and tissues.
PHC
Plant Holding Compartment
Phenol
Phenol is a highly poisonous, caustic crystalline chemical compound derived from coal tar or plant tar or manufactured synthetically. It has a distinctive, pungent odor and, in solution, is a powerful disinfectant.
Phenotype
A phenotype is the visible properties of an organism that are produced by the interaction of the genes and the environment.
Phenylephrine
Phenylephrine is a chemical used as a drug that constricts blood vessels. It is given by injection to increase blood pressure, in a nasal spray to relieve nasal congestion, and in eye drops to dilate the pupils.
Phlebotomy
Phlebotomy is the puncture or surgical opening of a vein in order to remove blood or to infuse fluids, blood or drugs in the treatment of many conditions.
Phonocardiogram
A phonocardiogram is a recording of heart sounds, which leaves a permanent record in the form of a tracing recorded on paper.
Phosphate (PO4)
Phosphate is a salt of phosphoric acid. Phosphates are extremely important in living cells, particularly in the storage and use of energy and the transmission of genetic information within a cell and from one cell to another.
Phosphate buffer
Phosphate buffer is a solution of at least two sodium or potassium phosphates in water (for example, monobasic sodium phosphate plus dibasic sodium phosphate). An acid or base can be added to the solution without its pH, or hydrogen ion concentration, changing markedly. Phosphate buffer is used to maintain pH of tissues within a relatively narrow range during experiments.
Phosphene
A phosphene is the conscious sensation of having perceived light, upon stimulation of a person’s visual apparatus in some manner other than by exogenous light impinging on the retina. The light may be colored or colorless, patterned or unstructured. Many types of phosphenes exist, including pressure, electrical, magnetic, and X-ray phosphenes. The best-known phosphene is the pressure phosphene, which consists of light sensations induced by pressure on the closed, but not necessarily dark-adapted, human eye (i.e., by rubbing the eyes in the dark). These are also known as deformation phosphenes.
Phosphoethanolamine
Phosphoethanolamine is an amino acid. If levels of alkaline phosphatase are abnormally low, large amounts of phosphoethanolamine may be detected in blood and urine samples.
Phosphofructose kinase
Phosphofructose kinase is an enzyme found in cells that participates in glucose metabolism.
Phosphoglyceric kinase
Phosphoglyceric kinase is an enzyme found in cells that participates in glucose metabolism by transferring a inorganic phosphate from 1,3 bisphosphoglycerate to adenosine diphosphate to form 3-phosphoglycerate and the energy generating compound, adenosine triphosphate.
Phospholipid
A phospholipid is a lipid (fat) containing phosphorus.
Phosphorus (P)
Phosphorus is a nonmetallic element. Phosphorus compounds are major constituents in the tissues of both plants and animals. In man, phosphorus is mostly concentrated in bone. Some phosphorus-concentrated compounds play an important part in energy conversions and storage in the body. In a pure state, phosphorus is toxic.
Photoelectric cell
A photoelectric cell is an electronic device whose electrical properties are modified by the action of light.
Photogrammatic
Photogrammatic means pertaining to three-dimensional multispectral mapping of the earth's surface. The images provide information about the maturity of crops, attacks on crops by pests, effects of pollution (forest, air and water) and many other conditions.
Photometer
A photometer is an instrument used to precisely measure the brightness or intensity of light.
Photometric
Photometric means a more precise measurement of the brightness or intensity of light, which can be digitized and calibrated.
Photomotograph
A photomotograph is a device used to determine reflex time by measuring movement in a particular limb as a reflex is initiated. The device uses a beam of light directed at a photovoltaic cell to measure the displacement of the limb as it moves during the reflex. Movement is detected by the beam of light and registered as a change in photocell voltage. The change in voltage is then recorded on paper to give a time-position plot of reflex action.
Photon
Photon refers to the smallest quantity of electromagnetic energy.
Photosensor
A photosensor is an instrument or biological structure that is sensitive to light.
Photosynthesis
Photosynthesis is the process by which green plants use the energy of light and a special substance called chlorophyll to synthesize carbohydrates (energy) from carbon dioxide and water.
Phototropism
Phototropism is the response of an organism to light, usually expressed as movement of a part of an organism toward or away from the stimulus of light, as when trees or plants grow toward sunlight.
Photovoltaic cell
A photovoltaic cell is a type of photoelectric cell that generates a voltage when a light beam falls on the boundary between two dissimilar substances within the cell.
Physiologic
Physiologic means of or relating to physiology, the science that studies the function of the body and the vital processes of living things, whether animal or plant.
Physiological
Physiological means of or relating to physiology.
Physiology
Physiology is the study of the functions or vital processes of living things, whether animal or plant.
Phytohemagglutinin (PHA)
Phytohemagglutinin (PHA) is a mitogen from plants that stimulates the activation of lymphocytes.
Phytomitogen
Phytomitogen is a mitogenic lectin causing lymphocyte transformation accompanied by mitotic proliferation of the resulting blast cells identical to that produced by antigenic stimulation. Phytohemagglutinin and concanavalin A are phytomitogens.
PI
Principal Investigator
PIA
Pre-Installation Acceptance Test
PIA
Project Initiation Agreement
PICA
Project Interface Control Agreement
PICS
Passive Thermal Control Subsystem
PID
Payload Implementation Document
Pilocarpine hydrochloride ophthalmic solution
Pilocarpine hydrochloride ophthalmic solution is a medication commonly used to treat glaucoma; it constricts the pupil and reduces pressure in the eye.
PIMS
Proposal Information Management System
PIND
Particle Impact Noise Detection
PIOL
Periodic Input/Output Loop
PIP
Payload Integration Package
PIP
Payload Integration Plan
PIP
Payload Implementation Plan
PIR
Program Information Request-Release (SE)
PIRR
Payload Integration Readiness Review
PISA
PI Support Area
Pitch
Pitch is a vertical (up-and-down) movement about a horizontal axis, such as the ear-to-ear axis of the head. Nodding would be a pitch movement of the head.
Pittsburgh Sleep Diary
The Pittsburgh Sleep Diary is an electronic instrument used to document and quantify subjectively reported sleep and waking behaviors.
Pituitary gland
The pituitary gland (a.k.a. hypophysis) is the master endocrine gland -- though it is about the size of a pea -- located beneath the hypothalamus in a bony cavity at the base of the skull. Its secretes many hormones, including thyroid-stimulating hormone, adrenocorticotropic hormone (ACTH), gonadotropins, growth hormone, prolactin, lipotropin, melanocyte-stimulating hormone, antidiuretic hormone (ADH), and oxytocin.
Pituitary receptors
A receptor is a structural protein molecule on the cell surface or within the cytoplasm that binds to a specific factor, such as a hormone from the pituitary gland in the case of pituitary receptors.
Pivot
A pivot is a short rod or shaft about which a related part rotates or swings.
Pixel
A pixel is a single volume element of the display of the computer terminal image.
Pkg
Package
PL
Payload
PL
Poison Liquid
Planimetry
Planimetry is the measurement of an area by tracing its boundary with a planimeter.
Plant biology
Thus far, plant biology research in NASA has focused primarily on understanding the mechanism of gravity sensing and transduction at the cellular and subcellular levels, the dramatic modifications of plant form and size that occur when plants are vibrated, the interaction of light with gravitropism, plant growth, development, and metabolism. Microgravity has been reported to affect such areas as plant morphology, directional growth, flowering, cell division and differentiation, and chromosomal integrity, and to cause changes in organelle functioning and cellular processes.
Plant growth chamber
The Svet plant growth chamber is a rectangular metal enclosure with windows on the front and on the right side of chamber walls for visual inspections by crewmembers and performance of experimental procedures. Reflective film has been applied to the interior walls of the chamber to intensify illumination, thereby facilitating growth conditions for the plants.
Plantar
Plantar means relating to the sole of the foot.
Plantar flexor
The plantar flexor is a group of muscles that bend the toes (or finger) downward, towards the sole (or palm).
Plantarflexion
Plantarflexion is the bending of the toes (or fingers) downward, toward the sole (or palm).
Plantaris
The plantaris is a muscle of the lower leg that is used to flex the foot.
Plasma
Plasma is the fluid portion of blood. It consists of a solution of various inorganic salts, such as sodium, potassium and calcium, and protein, as well as other trace substances.
Plasma membrane
The plasma membrane is the membrane which separates the inside of the red blood cells from the surrounding plasma.
Plasma protein
Hundreds of different proteins are present in blood plasma, including transport proteins (such as albumin and transferrin) that carry specific substances, fibrinogen and other blood coagulation factors, immunoglobulins that function as antibodies, and many other types of proteins.
Plasma total solids
Plasma total solids are all of the solid components of blood plasma that would be left after removal of water.
Plasma volume
Plasma volume is the volume of plasma in the blood. Plasma is the noncellular portion of blood and consists of water, various inorganic salts (such as sodium, potassium and calcium) and organic molecules, such as sugars and proteins. Normal plasma volume in an average adult is usually 3 liters, while total blood volume is about 5 liters.
Plasmid
Plasmid is a structure in cells consisting of DNA that can exist and replicate independently of the chromosomes. In organisms (other than man) that have been studied, it appears that plasmids interfere with gene activity.
Plasmin
Plasmin is a trypsin-like serine protease that is responsible for digesting fibrin in blood clots. It is generated from plasminogen by the action of another protease, lasminogen activator.
Plasminogen
Plasminogen is an inactive precursor of plasmin; it occurs at 200 mg/l in blood plasma.
Plastic nuclear track detector
Plastic nuclear track detectors are devices that measure radiation. They usually contain plastic nuclear track detectors, pieces of plastic wedged between a crystalline surface. As the radioactive particles impact the crystalline surface, they bounce off and scar the surface of the plastic by making tracks.
Platelet
A platelet is a disk-shaped structure present in the blood; they have several functions, all relating to stopping bleeding.
PLB
Payload Bay
Plethysmograph
A plethysmograph is a device for measuring and recording changes in volume of a part, organ, or whole body.
Plethysmography
Plethysmography is a method that measures changes in the volume of an organ or bodypart.
Pleural effusion
Pleural effusion is an abnormal accumulation of fluid in the intrapleural spaces of the lungs, characterized by fever, chest pain, dyspnea and nonproductive cough.
PLSS
Portable Life Support System
PLT
Pilot
PM
Pressurized Module
PMA
Platform Management Application
PMAD
Power Management and Distribution
PMC
Permanently Manned Capability
PMIS
Payload Management Information System
PMM
Payload Mission Manager
PMO
Program Management Office
PMP
Program Management Plan
PMR
Program Management Report
PMR
Program Management Review
PMS
Performance Management System
PMS
Physiological Measurement System
PMS
Platform Management System
PMSR
Physiological Measurement System Requirement
PMT
Photo-Mechanical Transfer
PN
Part Number
Pneumatic
Pneumatic means inflated or operated by air (pressure).
Pneumatic cuff
A pneumatic cuff is a device that can be inflated and deflated by the introduction or removal of air; it is commonly used to measure blood pressure in the upper arm (or thigh) of humans.
Pneumococcal
Pneumococcal refers to Pneumococcus, which is another name for Streptococcus pneumoniae; a species of Gram-positive, lancet-shaped diplococci frequently occurring in chains; cells are readily lysed by bile salts. Virulent forms are enclosed in type-specific polysaccharide capsules; there is also a specific somatic antigen (M protein) for each of the approximately 85 types, and somatic C carbohydrate common to all types. They are normal inhabitants of the respiratory tract, and are perhaps the most common causative agents of meningitis, sinusitis, and other infections.
Pneumograph
A pneumograph is an instrument used to record respiratory rate from movements on the body surface.
Pneumography
Pneumography is the measure of respiratory movements during respiration (e.g. respiratory rate) with an instrument called a pneumograph.
Pneumonitis
Pneumonitis is an inflammation of the lungs. It may be caused by a virus or may be a hypersensitivity reaction to chemicals or organic dusts, such as bacteria, bird droppings, or mold. Dry cough is usually a symptom. Treatment depends on the cause but includes removal of any offending agents and the administration of corticosteroids to reduce inflammation.
Pneumotachograph
A pneumotachograph is an instrument used to measure the instantaneous flow of respiratory gases.
PO
Purchase Order
POCC
Payload Operations Control Center
POD
Payload Operations Director
POF
Pad Operations Facility
POI
Products of Inertia
POL
Paints, Oils, and Lubricants
Polar orientation
Polar orientation refers to the process of aligning or positioning in a three-dimensional space with respect to a polar reference system. A polar reference system aligns with either of two extremities of an axis through a sphere, such as the Earth's North and South poles.
POLCAT
Pollution Characterization by Absorption on Spectroscopy
Poliomyelitis
Poliomyelitis is the inflammation of the gray matter of the spinal cord.
Poliovirus
Poliovirus is the piconarvirus that causes poliomyelitis in humans (also called poliomyelitis virus).
Pollen
Pollen is the powdery, yellowish grain derived from seed plants that develops into the male reproductive cell.
Pollutant
A pollutant is something that makes another (such as air, water or soil) unfit, harmful, or impure.
Polymer
A polymer is a natural or synthetic compound of high molecular weight composed of long chains of repeating units, each relatively light and simple.
Polymerase Chain Reaction (PCR)
Polymerase Chain Reaction, or PCR, is a process which permits scientists to make unlimited copies of genes. This is done with a single molecule of DNA. One hundred billion copies of the DNA can be generated in a few hours. This technique is used to investigate and diagnose bacterial diseases, viruses associated with cancer, and genetic diseases such as diabetes mellitus.
Polymorphonuclear leukocyte (PMN)
Polymorphonuclear leukocytes are large granular white blood cells (namely neutrophils, basophils and eosinophils) that have the capacity for phagocytosis (destruction by ingestion) of foreign cells and materials. In addition, these cells, when stimulated, can degranulate and release chemicals such as histamine into the blood stream.
Polyp
Polyp is a general descriptive term used with reference to a mass of tissue that bulges or projects outward, or upward from the normal surface level. Polyps are also a larval form of some invertebrates, such as jellyfish.
Polypeptide
A polypeptide is a molecular chain of amino acids.
Polysaccharide
A polysaccharide is a carbohydrate formed from many monosaccharides (simple sugars) joined together in long linear or branched chains. Polysaccharides have two important functions: (1) as a storage form of energy (glycogen in man) and (2) as structural elements of cells.
Polysomnography
Polysomnography is the continuous and simultaneous monitoring of relevant normal and abnormal physiological activity during sleep.
Polyurethane
Polyurethane is any of the various polymers containing NHCOO linkages. These polymers are used in manufacturing flexible and rigid foams, elastomers, and resins.
POMT
Planning Operations Management Team
Pons varolii
The pons varolii (or pons) is the part of the brain stem that links the medulla oblongata and the thalamus, bulging forward in front of the cerebellum, from which it is separated by the fourth ventricle. It contains numerous nerve tracts between the brain and the spinal cord.
POO
Payloads Operations Office
POP
Polar Orbiting Platform
POP
Program Operating Plan
Popliteal nerve
The popliteal nerve is the larger of the two terminal branches of the sciatic nerve which descends along the back part of the thigh, behind the knee, and on to the soleus (calf muscle).
Post-hoc comparison (post-hoc test)
A post-hoc comparison (post-hoc test) is a type of statistical test used when a difference has been found by analysis of variance of more than 2 groups. A post-hoc test is used to determine which groups are different.
Posterior
Posterior describes or relates to the back (or dorsal) portion of the body.
Postural
Postural means relating to or effected by posture. Posture is defined as the position of the limbs or the carriage of the body as a whole.
Postural equilibrium
Postural equilibrium is a reflexive mechanism that anticipates changes in body orientation when the body is thrown off balance. The reflex makes appropriate adjustments of the body to prevent falling; for example, when the body is suddenly pushed to the right, even before it can fall, the right leg extends instantaneously in a reflexive motion.
Posturography
Posturography is the collection of data related to upright posture, balance, and equilibrium. The patient or subject stands on a posture platform, which can be tilted, and looks at visual stimuli that are controlled by the operator. The position of different parts of the body, including the head and hips, and the force of the feet on a foot plate are measured.
Potable
Potable describes water that is fit to drink.
Potassium (K)
Potassium is the principal cation (positively charged ion) in intracellular fluid and is of primary importance in its maintenance. Proper balance of potassium, calcium and magnesium ions are essential for the normal function of muscles.
Potassium gluconate
Potassium gluconate is another name for gluconic acid potassium salt and is used in hypokalemia as a potassium replenisher.
Potassium-40
Potassium-40 is a naturally occurring radioactive potassium isotope. It exists as 0.0119 percent of all potassium in the body and is the primary source of natural radioactivity in living tissue.
Potassium-42
Potassium-42 is an artificial potassium isotope with a half life of 12.47 years which is used as a tracer in studies of potassium distribution in body fluid compartments.
Potentiometer
A potentiometer is an instrument used to precisely measure electromotive forces. A part of the voltage to be measured is balanced against that of a known electromotive force and computed therefrom by the law of fall of potential.
Power spectral analyses
Power spectral analyses are analyses of power spectra. Power spectra can be constructed for a collection of data in the form of waves, such as electrocardiograms. The power at each frequency is determined, and if data from a number of time points are examined, a three-dimensional graph can be constructed. The analysis can provide information about such processes as neural control of the fluctuations in power at different frequencies.
POWG
Payloads Operation Working Group
PP
Passive Package
PPG
Photo Plethysmograph
PPM
Parts per Million
PPPB
Payload Program Policy Board
PPR
Payload Preparation Room
PPS
Pulses per Second
PR
Purchase Request
PR
Problem Report
pr
Pair
PRACA
Problem Reporting and Corrective Action
PRCB
Program Requirements Control Board
PRCBD
Program Requirements Control Board Directive
PRD
Program Requirements Document
Precipitant
A precipitant is anything that causes a substance in solution to separate from it as a solid.
Precipitant solution
A precipitant solution is a solution that usually contains salts which pass through a semi-permeable membrane and cause protein molecules in a solution to become a solid.
Precordial
Precordial means of or relating to the precordium, which is the region over the heart and the lower part of the thorax.
Prednisone
Prednisone is a glucocorticoid that is prescribed in cases of severe inflammation and immunosuppression.
Predominance
Predominance means exhibiting a superiority in weight, quantity, power, or importance.
Pregnanediol
Pregnanediol is a crystalline, biologically inactive compound found in the urine of women during pregnancy or in the secretory phase of the menstrual cycle. A dihydroxyl derivative of the saturated steroid pregnane, this compound is formed by the reduction of progesterone.
Prel
Preliminary
Premature atricular contraction
Often, a small area of the heart becomes much more excitable than normal, causing an abnormal impulse to be generated during the time interval between normal impulses. This initiates a premature contraction of the atria of the heart. Premature atrial contraction can result from ischemia of a small area of muscle, overuse of stimulants such as caffeine or nicotine, lack of sleep, anxiety or other debilitating states.
Premature ventricular contraction
Often, a small area of the heart becomes much more excitable than normal, causing an abnormal impulse to be generated during the time interval between normal impulses. This initiates a premature contraction of the ventricles of the heart. Premature ventricular contraction can result from ischemia of a small area of muscle, overuse of stimulants such as caffeine or nicotine, lack of sleep, anxiety or other debilitating states.
Prep
Prepare
Press
Pressure
Pressure suit (antigravity suit, G-suit)
A pressure suit or antigravity suit is a garment worn by space travelers during launch and/or landing. It exerts pressure, usually by means of inflatable air bladders, on the thighs and abdomen to lessen the pooling of blood in the lower part of the body during acceleration.
Presyncopal
Presyncopal relates to the symptoms of syncope, such as lightheadedness, sweating and blurred vision.
Presyncope
Presyncope is a condition characterized by symptoms and signs (such as feeling faint) of imminent syncope (a lapse into unconsciousness caused by transient cerebral hypoxia).
Primer
A primer is a short sequence of RNA or DNA from which DNA replication can initiate.
Priroda
The Priroda module is the latest module added to the Mir Space Station. It docked with Mir during the Mir 21 mission, and is now configured as a laboratory where Earth observation and microgravity research is being conducted.
PRM
Payload Retention Mechanism
Probe
A probe is an instrument used to investigate an unknown configuration, condition, or region.
Proc
Procedure
Proc
Proceedings
Procto-sigmoidoscopy
Procto-sigmoidoscopy is the examination of the rectum and sigmoid by means of the sigmoidoscope, an instrument which allows for the direct visualization of the mucous membrane lining the colon.
Prod
Produce
Prog
Program
Progenitor
A progenitor is an ancestor or precursor.
Progress
Progress is the name given to an unmanned Russian transport vehicle which docks to the Mir Space Station, delivering food and supplies when needed.
Proj
Project
Proliferation
Proliferation means to reproduce or increase rapidly and repeatedly.
PROM
Programmable Read Only Memory
Promethium-147
Promethium-147 is an artificially produced radioactive chemical element with the atomic number 61, atomic weight 145, and half-life of 2.6 years. It is produced in nuclear reactors and is used in making phosphorescent materials. When promethium-147 is mixed with a phosphor, it produces a radioluminescent light. Promethium-147 is used in luminescent coatings for instrument dials and as a power source for semiconductor solar batteries for space use. It is also used as a source of X-rays for medical applications in areas of the world where electrical power is not generally available.
Promyelocytic leukemia cells
Promyelocytic leukemia cells are abnormal promyelocytes, with very heavy granulation obscuring the basophilic cytoplasm. Leukemia of the promyelocytic cells is classified as M3 leukemia, a form of Acute Myeloid Leukemia (AML).
Prop
Property
Prophylactic
Prophylactic is an agent that prevents the spread of disease.
Proprioceptive function
Proprioceptive function is the activity relating to a proprioceptor, a specialized sensory nerve ending that monitors internal changes in the body brought about by movement and muscular activity. Proprioceptors located in muscles and tendons transmit information that is used to coordinate muscular activity.
Proprioceptive system
The proprioceptive system is made up of specialized sensory nerve endings that monitor internal changes in the body brought about by movement and muscular activity. Proprioceptors located in muscles and tendons transmit information that is used to coordinate muscular activity.
Proprioceptors
Proprioceptors are specialized sensory nerve endings that monitor movement and position of parts of the body. Proprioceptors located in muscles and tendons transmit information that is used to coordinate muscular activity.
Prostaglandin
Prostaglandins are one of a group of hormone-like substances present in a wide variety of tissues and body fluids; they have many actions, such as dilation and constriction of veins, stimulation of intestinal muscles, and contraction of uterine muscle.
Prostatic massage
A prostatic massage is the manual expression of prostatic secretions by digital rectal technique. It is also usedto treat various congestive and inflammatory prostatic conditions by the emptying the prostatic sini and ducts by repeated downward compression maneuvers.
Prosthesis
A prosthesis (plural prostheses) is any artificial device that is attached to the body as an aid. Prostheses include dentures, artificial limbs, hearing aids and implanted pacemakers.
Protease
Protease is an enzyme that causes the decomposition of protein.
Protein
Proteins are one of a group of organic compounds of carbon, hydrogen, oxygen and nitrogen with sulfur and phosphorus possibly present. The protein molecule is a complex structure made up of one or more chains of amino acids linked by peptide bonds. Proteins are essential constituents of the body; they form the structural material of muscles, tissues, organs, etc. and are equally important as regulators of function as enzymes and hormones. Proteins can also be converted into glucose and used as an energy source by the body.
Protein crystal growth
When a protein solution and a salt solution are brought together, protein crystal growth starts. Under microgravity conditions the crystals grow much larger and more highly ordered than under 1g conditions.
Protein metabolism
Protein metabolism is the process of production, use, and excretion of protein in the human body. Proteins are essential chemical substances that the body uses in many processes, including energy production. Proteins form the structural material of muscle, tissue, organs, and when they make up enzymes and hormones, they also regulate the function and behavior of other cells.
Protein synthesis
Protein synthesis is the process of anabolic metabolism (simple substances converted into more complex compounds) that forms new proteins.
Proteinase K
Proteinase K (also known as Endopeptidase K) is an enzyme that catalyzes the hydrolysis of keratin and other proteins with subtilisin-like specificity; it also hydrolyses peptide amides. Endopeptidase K comes from the mold Tritirachium album Limber.
Proteus miribilis
Proteus miribilis is a species of facultatively anaerobic bacteria found in putrid meat, infusions, and abscesses; it is also reported to be a cause of gastroenteritis and urinary tract infections.
Protista
Protista, a Greek word meaning “primitive” or “first,” is the third kingdom in the classification of life forms. Protista consists of single-celled microbes -- such as algae, bacteria, fungi, and protozoa -- and multicellular organisms that are not differentiated (organized) into distinct tissues and organs, as are higher animals and plants.
Proton
A proton is a positively-charged particle forming the nucleus of hydrogen and present in the nuclei of all elements.
Provocative
A provocative move is one which will induce, or cause, certain symptoms or effects.
Proximal
Proximal means anatomically situated close to the origin or point of attachment, or close to the median, or middle, line of the body.
PRR
Preliminary Requirements Review
PRR
Payload Requirements Review
PRS
Problem Reportings
PRSD
Power Reactant Storage and Distribution System
PRWM
Primate Restraint and Waste Management System
PS
Payload Specialist
PS
Payload Station
PS
Procurement Source
PS
Particulate Solid
PSA
Pressure Switch Assembly
PSC
Platform Support Center
PSCN
Program Support Communications Network
PSDP
Payload Station Distribution Panel
Pseudomonal Protein A
Pseudomonal Protein A is antigen-protein associated with Pseudomonas, a genus of motile, polar flagellate, nonsporeforming, and strictly aerobic bacteria.
Pseudomonas
Pseudomonas is a genus of motile, polar flagellate, non-sporeforming, strictly aerobic bacteria containing straight or curved, but not helical, Gram-negative rods, which occur singly. The metabolism is respiratory, never fermentative. They occur commonly in soil and in fresh water and marine environments. Some species are plant pathogens. One species is a specialized mammalian parasite, while others are only occasionally pathogenic to animals.
Pseudomonas aeruginosa
Pseudomonas aeruginosa is a species of bacteria found in soil, water and clinical specimens; it is the causative agent of blue pus and is occasionally pathogenic for plants. P. aeruginosa usually causes infections in humans only when there is a defect in host defense mechanisms.
psi
Pounds per Square Inch
psia
Pounds per Square Inch Absolute
Psig
Psig is an abbreviation for pounds per square inch
psig
Pounds per Square Inch Gauge
PSK
Phase Shift Keyed
PSM
Payload Science Monitor
Psoas
The psoas is one of two muscles that run from the spine to the top of the upper leg bone and act to flex the lower back and thigh.
PSP
Payload Signal Processor
PSP
Project Support Plan
PSS
Payload Specialist Station
PSSC
Program Science Steering Committee
PSSE
Payload Specialist Station Equipment
PSSI
Payload Support Systems and Integration
PSSP
Primate Specimen Stowage Panel
PST
Project Support Team
PSTE
Payload Systems Test Equipment
PSY
Project Synthesis
Psych
Psychology
Psychiatric
Psychiatric means of or relating to psychiatry, the study of mental, emotional and behavioral disorders including their diagnosis, management and prevention.
Psychiatry
Psychiatry is the medical specialty concerned with the prevention, treatment and study of mental, emotional and behavioral disorders.
Psychological
Psychological means of or relating to psychology, the study of the behavior of man and animals.
Psychomotor
Psychomotor means pertaining to or causing voluntary movements usually associated with neural activity.
Psychosomatic
Psychosomatic pertains to the relationship of the mind and body.
PTC
Post Test Critique
PTCU
Passive Thermal Conditioning Unit
PTD
Payload Technical Documentation
PTD
Provisioning Technical Documentation
PTS
Psychomotor Test System
PTT
Press-To-Talk
PU
Panel Unit
Puffy face syndrome
Puffy face syndrome refers to the swollen appearance of the face caused by the redistribution of body fluids from the lower body to the upper body. In space, this occurs due to the lack of downward gravitational forces in microgravity.
Pulmonary
Pulmonary means of or relating to the lungs.
Pulmonary blood volume
Pulmonary blood volume is the volume of blood in the lungs.
Pulmonary capillary blood flow
Pulmonary capillary blood flow is the measure of the rate of blood flow in the capillaries of the lungs.
Pulmonary diffusing capacity
Pulmonary diffusing capacity is the diffusion capacity of oxygen and carbon dioxide through the lung tissue.
Pulmonary function
Pulmonary function is the ability of the lungs to exchange oxygen and carbon dioxide.
Pulmonary physiology
Pulmonary physiology is the research area which focuses on studying the lungs.
Pulmonary ventilation
Pulmonary ventilation is the passage of air into and out of the respiratory tract.
Pulpitis
Pulpitis is the inflammation of tooth pulp.
Pulsatile
Pulsatile means throbbing or beating rhythmically.
Pulse pressure
Pulse pressure is the calculated difference between the systolic and diastolic blood pressure measurements.
Pulse rate
Pulse rate is the number of heart beats per minute.
Pulsed field gel electrophoresis (PFGE)
Pulsed field gel electrophoresis (PFGE) is a method used to separate high molecular weight linear DNA fragments that are greater than 50 kilobases (kb) in size. Fragments are separated by pulsing an electrical field across an agarose gel rather than applying a constant field as used in conventional electrophoresis.
Pulsing
Pulsing is a method of moving that is used by the jellyfish.
PUR
Procedure Update Request
Purification
Purification is the act or process of cleansing.
Pursuit tracking
Pursuit tracking is using the eyes to follow a moving point across a backdrop.
Pushrod
A pushrod is a rod moved by a cam to operate the valves of a system.
PUSS
Pallet Utility Support Structure
PV
Photovoltaic
PWA
Program Work Authorization
PWB
Printed Wire Boards
PWBS
Project Work Breakdown Structure
PWC
Primary Work Code
PWR
Power Supply Unit
Pwr
Power
Pyelonephritis
Pyelonephritis is an inflammation of the renal parenchyma, calyces and pelvis particularly due to a local bacterial infection.
Pyemia
Pyemia is a systemic disease caused by the multiplication of pyogenic (pus forming) organisms causing multiple abscesses.
Pyld
Payload
Pyramidal neuron
Pyramidal neurons are a type of neuron found in the cerebral cortex of the brain and have pyramid-shaped cell bodies.
Pyrex
Pyrex is used for glass and glassware that contains appreciable oxide of boron; it is resistant to heat, chemicals and electricity.
Pyridinoline
Pyridinoline is an amino acid derived from lysine that cross-links the collagen found in bone, cartilage and other connective tissues, such as ligaments, tendons, fascia and blood vessels.
Pyridium cross-link
Pyridinium cross-links are products of the degradation of type I collagen and are released into the circulation as collagen is degraded during bone resorption. They are cleared from the circulation by the kidneys and excreted in the urine. Because these collagen metabolites are not degraded further nor absorbed from the diet, their excretion directly reflects the rate of bone resorption.
Pyrolysis
Pyrolysis is the decomposition of a substance by heat.
Pyruvate kinase
Pyruvate kinase is an enzyme found in cells that participates in glucose metabolism by transferring an inorganic phosphate from phosphoenolpyruvate to adenosine diphosphate to form pyruvate and the energy generating compound, adenosine triphosphate.
Pyruvate oxidation
Pyruvate oxidation refers to the act of oxidizing pyruvic acid via a complex series of reactions in the Krebs cycle to yield carbon dioxide and energy in the form of ATP (adenosine triphosphate).
q
Quality Factor
QA
Quality Assurance
QC
Quality Control
QCM
Quartz Crystal Microbalance
QDR
Qualification Design Review
QRS complex
The QRS complex is a group of deflections in an electrocardiographic (ECG or EKG) tracing that represent the depolarization of the ventricles of the heart, which initiates contraction of the ventricles.
QTY
Quantity
Quadriceps
The quadriceps is one of the great extensor muscles of the legs, running from the front of the thigh to the knee. It acts to extend the leg and to flex the thigh.
Quadriceps femoris
The quadriceps femoris is a muscle of the thigh which acts to extend the leg and to flex the thigh.
Quail
A quail is a small, short-tailed chickenlike bird found in the wild.
Qual
Quality
Quarantine
Quarantine is the enforced isolation or restriction of free movement imposed to prevent the spread a contagious disease.
Quasi-steady
Quasi-steady means seemingly, but not actually, a steady state of movement.
Quiescent
Quiescent means to be still or inactive; dormant.
Quinidine
Quinidine is an antidysrhythmic agent used as a bisulfate, gluconate, polygalacturonate, or sulfate. It is prescribed in the treatment of atrial flutter, atrial fibrillation, premature ventricular contractions, and tachycardias.
Quinidine sulfate
Quinidine sulfate is a medication used to treat irregular heart rhythms (arrhythmias) and maintain a normal heart rate.
R
Return Pin Number
R
Right Side
R&D
Research and Development
R&O
Routing and Operations
R&QA
Reliability and Quality Assurance
R-I
Receiving-Inspection
R-R interval
The R-R interval (normally about 0.8 seconds) is a measure of time lapsed between the R waves, electrical signals given off by the beating of the heart, and measured and recorded on an electrocardiogram (EKG). The R waves occur during the contraction (also called depolarization or systole) of the heart and are part of the QRS complex. An R wave is noticeable as the largest upward spike on the EKG recording of a normal heartbeat, usually measuring slightly less than one millivolt.
R/IM
Refrigerator Incubator Module
R2A media
R2A media is a non-selective media that supplies nutrients and support growth for a variety of heterotrophic bacteria. It is used in the isolation and total count of bacteria found in water.
RA
Requesting Agency
RA
Radioactive
RAAB
Remote Amplification and Adaption Box
RAD
Radiation Absorbed Dose
rad/s
Radians per Second
Radar
Radar is a method of detecting distant objects and determining their position, velocity, or other characteristics by analysis of very high frequency radio waves reflected from their surfaces. Radar also refers to the equipment used in such detecting.
Radial immunodiffusion test
The radial immunodiffusion test is an agarose gel based test in which the antigen diffuses outward into an antibody-containing gel. A ring of precipitate is formed which provides visual evidence of equivalence and concentration is evaluated by measuring the diameter of the arc.
Radiation
Radiation is energy in the form of particles or waves emitted in straight lines from a source such as a star or the nucleus of unstable radioactive atoms.
Radiation biology
Radiation biology is the study of the ways in which radiation affects biological tissue and organisms.
Radiation dose
A radiation dose is the quantity of radiation received.
Radioactive
Radioactive describes the spontaneous disintegration of atomic nuclei accompanied by the emission of small particles. Depending on the type of emission, scientists define alpha (helium nuclei), beta (electrons or positrons), and gamma radiation (short-wavelength electromagnetic waves).
Radioactive carbon
Radioactive carbon is an isotope of carbon with two extra electrons, also known as carbon-14. Carbon-14 is used in life sciences research to mark metabolic compounds. In carbon dating it is used to determine, for example, the age of dinosaur bones.
Radioactive isotope
A radioactive isotope, or radioisotope, is an isotope of a chemical element with an unstable nucleus that dissipates excess energy by emitting radiation in the form of alpha, beta, and gamma rays.
Radioenzymatic assay
Radioenzymatic assay is an enzyme used as the indicator system; when the enzyme and the antigen-antibody complex bind, a color indicator or other easily recognizable sign occurs.
Radiograph
A radiograph is an image film produced by X-ray.
Radiography
Radiography is a method of examination that directs X-rays through the body to produce images (radiographs) on photographic plates or fluorescent screens. Radiography can be used to diagnose broken bones, gastric ulcers, kidney or gallbladder stones, and dental cavities.
Radioimmunoassay
Radioimmunoassay refers to a method of measuring hormones in the blood. Most hormones are present in extremely minute quantities, and require a highly sensitive technique such as this. In radioimmunoassay, an antibody is developed that is highly specific for the hormone being measured. A small quantity of the antibody is mixed with a quantity of fluid (usually plasma) containing the hormone to be measured. Standard hormones, tagged with a radioactive isotope, are also added to the mixture. There is not enough antibody to bind with both the tagged hormone and with the hormone to be measured. The natural hormone and the tagged hormone compete for binding sites. The quantity of each of the hormones that binds is proportional to the concentration of each. After binding has reached equilibrium, the quantity of radioactive hormone bound with antibody is measured. If a large amount of radioactive hormone has bound with antibody, then only a small amount of natural hormone was available to compete with the radioactive hormone.
Radioisotope
A radioisotope is an unstable radioactive isotope that decays to a stable state by emitting radiation.
Radiology
Radiology is the science of high-energy radiation and of the sources and the chemical, physical, and biologic effects of such radiation. It is also the branch of medicine concerned with the use of radiation for the diagnosis and treatment of disease.
Radioluminescent
Radioluminescence is low-level lighting produced by nuclear radiation. Common radioluminescent materials include tritium, promethium-147 and radium-226. Radioactive decay of the material emitts particles that interact with a second substance, such as phosphor or zinc sulfide, to produce light. Radioluminescent material is used on watch dials to allow visibility in the dark.
Radiometer
A radiometer is a device for determining the penetrative power of X-rays; also called a roentgenometer.
Radius
The radius is the outer and shorter bone of the forearm.
RAHF
Research Animal Holding Facility
RAHF-V
Research Animal Holding Facility Verification Test
RAM
Random Access Memory
Ramp test
A ramp test in lower body negative pressure (LBNP) studies is a gradual decrease in pressure (increase in negative pressure), with subjects remaining exposed to each pressure for only a short time (e.g.., 5 minutes). Heart rate and blood pressure are usually monitored during the test. The ramp test may be a prelude to a "soak," exposure of subjects to moderate negative pressure for a long period.
RAMTEK
Brand Name of a Particular Color CRT
Range of motion
Range of motion is all of the normal movements of a joint, in all directions in which the joint can move.
Rapid Eye Movement (REM)
Rapid Eye Movement (REM) is the sleep stage during which the muscles of the eyeballs are in constant motion behind the eyeballs. This is the phase in which dreaming is thought to occur.
Raster
A raster is the pattern formed by a scanning beam (such as an electron beam) when it moves from side to side and top to bottom so that the beam scans the entire object. It is also a pattern of dots that form an image, such as that on a television or computer screen.
RATS
Research Animal Housing Facility (RAHF) Automated Training System
RAU
Remote Acquisition Unit
RAUS
Remote Acquisition Unit (RAU) Simulator
RBE
Relative Biological Effectiveness
RBG
Red, Blue, Green
RBID
Request Block ID
RC
Reference Configuration
RCA
Radio Corporation of America
RCC
Reinforced Carbon-Carbon
RCD
Record
RCN
Requirements Change Notice
RCS
Reaction Control System
RDT&E
Research, Development, Test and Engineering
Readaptation
Readaptation is the adjustment of the organism and its physiological processes to its previous state. For example, after being in microgravity or weightlessness, astronauts must readapt to earth gravity by strengthening their muscles.
Real-time (R-T, RT)
Real-time is a term used to describe an activity as it is occurring. For example, if a researcher on Earth is engaged in a conversation with an astronaut in space, the event is said to occur in real-time. Listening to a recording of this conversation at a later date would not be considered real-time.
Rec'd
Received
Recommended Daily Allowance (RDA)
The Recommended Daily Allowance (RDA) is the amount of nutrients, particularly kilocalories, protein, vitamins and minerals recommended as a necessary part of one's daily food intake to maintain health.
Recovery (R+)
Recovery refers to the day and time when the spacecraft lands and human, animal and plant organisms are re-introduced to earth gravity; sometimes abbreviated R+0, to indicate zero days after recovery, i.e., day of landing.
RECP
Request for Engineering Change Proposal
Rectus femoris
The rectus femoris is a muscle of the anterior thigh, which acts to extend the knee.
Recumbency
Recumbency is the state of lying back or reclining.
Recumbent
Recumbent means lying down or leaning backwards.
Red blood cell (RBC)
A red blood cell (RBC) contains the pigment hemoglobin, which has the principle role of the transport of oxygen.
Red blood cell mass
Red blood cell mass is the amount of red blood cells in the body.
REDAF
Research Data Facility
REE
Rare-Earth-Element
REFCON
Reference Configuration
Reflectance
Reflectance is the ratio of the total radiant flux, as of light, reflected by a surface to the total striking the surface.
Reflectometer
A reflectometer is an instrument used to measure the reflectance of a surface.
Regulatory Physiology
The Regulatory Physiology discipline is composed of seven subdisciplines: 1) Circadian Rhythms (biological rhythms like the sleep/wake cycle), 2) Endocrinology (study of the regulation of body processes by hormones), 3) Fluid and Electrolyte Regulation (regulation of body fluid and electrolytes by the kidneys and by specialized mechanisms), 4) Hematology (study of red blood cells and their production), 5) Immunology (study of the immune system which protects the body from infection), 6) Metabolism and Nutrition, and 7) Temperature Regulation.
REJ
Reject
Relativistic particles
Relativistic particles are particles that move at such high speeds (close to the speed of light) that their properties (such as mass) change significantly in accordance with the theory of relativity. An example is a relativistic electron.
REM latency
REM latency is defined as the elapsed time from sleep onset, i.e., the first appearance of Stage 2 sleep until the onset of the first REM period of the night.
Remote sensing
Remote sensing is the ability to measure, observe or study something distant through the use of special instruments, devices or electronics, such as the use of satellites to study crop growth.
Renal
Renal means of or relating to the kidney.
Renal clearance
Renal clearance is used to express the ability of the kidneys to clean or clear the plasma of various substances.
Renal physiology
Renal physiology is the study of the processes, metabolism and function of the renal system, which is composed of the kidneys as its main component.
Renal stone
A renal stone, or kidney stone, is a hard pebble-like mass commonly composed of calcium oxalate that forms within the kidney. Some kidney stones cause pain and must be removed from the body using surgery or ultrasound techniques.
Renal stone-forming salts
Renal stones are formed from the renal stone-forming salts calcium oxalate, calcium phosphate, uric acid, struvite and cystine. The most common substance making up renal stones is calcium oxalate, which makes up about 70% of all formed stones.
Renal system
The renal system contains the kidneys as its primary component. The system functions primarily to regulate the fluid and electrolyte balance throughout the body by controlling the thirst sensation and the urinary excretion process.
Renal, fluid and electrolyte physiology
Renal, fluid and electrolyte physiology is the study of fluid and electrolyte regulation within the body. The kidneys regulate the body's fluid and electrolyte balance. If kidney (renal) function is impaired, dehydration, loss of electrolytes and dysfunction of the circulatory system result.
Renin
Renin is an enzyme that converts angiotensinogen to angiotensin I, the precursor of a hormone (angiotensin II) that constricts blood vessels.
REP
Repetition
Rep
Representative
Reproductive
Reproductive is a term relating to the mechanism by which organisms give rise to others of the same kind.
RESC
Recording and Simulation Chamber
Reserve Science Activity
A Reserve Science Activity is a science activity that is not scheduled in the crew timeline. These activities are performed when additional crew time becomes available.
Residual volume (RV)
Residual volume (RV) is the volume of air still remaining in the lungs after the most forceful expiration; this volume averages about 1200 ml.
Resolidification
Resolidification is the term used to describe the solidification of a material, such as a alloy, metal or salt, after it is treated and has become more fluid. The term resolidification indicates that the material was solid before the treatment began. Examples for such treatments are heating up or applying pressure or combinations of both.
Resolution
Resolution is the ability optically to distinguish details such as the separation of closely approximated objects.
Resorption
Resorption is the act of removal by physiological absorption.
Resp
Responsible
Respiration
Respiration is the act of breathing air into and out of the lung so that vital gases can be absorbed into the body.
Respiration rate
Respiration rate is a measure of the number of breaths taken in a set interval of time, usually one minute.
Respiratory
Respiratory means of or relating to breathing, such as inhaling and exhaling (respiration).
Respiratory exchange ratio
The respiratory exchange ratio is the ratio of carbon dioxide output to oxygen intake. The value changes under different metabolic conditions, but the average value is considered to be 0.825.
Respiratory gas exchange
Respiratory gas exchange is the transfer of oxygen and carbon dioxide from the lungs to the blood and from the blood to the lungs.
Respiratory Minute Volume (V(E))
Respiratory Minute Volume (V(E)) is the total amount of new air moved into the respiratory passages each minute. It is equal to the tidal volume times the respiratory rate (TV x RR), usually averaging about 6 liters per minute.
Respiratory quotient
The respiratory quotient is the ratio of carbon dioxide output to oxygen usage.
Respiratory rate
Respiratory rate is the rate of breathing (respiration) expressed as breaths per minute.
Respiratory syncytial virus
Respiratory syncytial virus is an RNA-containing virus of the genus Pneumovirus that causes minor respiratory infection with rhinitis and cough in adults, but is capable of causing bronchitis and bronchopneumonia in young children; named for its tendency to form syncytia in tissue culture.
Respiratory system
The respiratory system is the combination of organs and tissues associated with breathing. It includes the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles and lungs (and also the diaphragm and other muscles associated with breathing movements).
Restriction fragment length polymorphism (RFLP)
Restriction fragment length polymorphism (RFLP) is the variability that occurs in electrophoretic banding patterns of specific DNA fragments from different individuals or strains of a species. Restriction enzymes, which recognize a specific target nucleotide sequence in DNA and break the DNA chain at that target, cleave DNA in specific places. RFLP is caused by the presence of a restriction enzyme cleavage site in the genome of one individual and the absence of that site in another individual . The length of DNA fragments that result from cleavage by the enzyme are therefore different for these individuals or microorganism strains. This information can be used to make a DNA "fingerprint" of an individual or strain, or a genetic map for a species.
RET
Return location
Retention
Retention is the process of holding back, or retaining. During the excretion of fluids from the body by the kidneys, electrolytes and other substances dissolved in urine are excreted, while retention of water occurs, producing a more concentrated urine.
Reticulocyte
A reticulocyte is an immature red blood cell or erythrocyte.
Reticuloendothelial
Reticuloendothelial refers to a tissue consisting of phagocytic cells lining the vascular and lymph channels of the liver, bone marrow and spleen. These cells, like macrophages, chemically digest red blood cells and release hemoglobin.
Retina
The retina is a sensory membrane that lines the eye and is composed of several layers, including one that contains the light sensitive cells (rods and cones). The retina receives the image formed by the lens and converts it into chemical and nervous signals, which reach the brain by way of the optic nerve.
Retinal
Retinal means pertaining to the retina.
Retroreflective
Retroreflective means reflecting light (or other radiation) so that the paths of the reflected rays are parallel to those of the rays being reflected (incident rays).
Retrorockets
A retrorocket is a rocket engine whose exhaust is directed to hinder, stop or reverse motion.
Retrosternal
Retrosternal pertains to the area behind the sternum.
REV
Revision
Revitalization
Revitalization refers to the process of imparting new life or vigor to (as in cleansing the air of impurities).
RF
Radio Frequency
RF
Return Flux
RFI
Radio Frequency Interference
RFP
Request for Proposals
RFQ
Request for Quotation
RH
Relative Humidity
RHCP
Right Hand Circularly Polarized
RHEC
Rhesus Experiment Chamber
Rhodotorula
Rhodotorula is a genus of yeast, usually pink to red, that is of questionable pathogenic severity. Rhodotorula is generally introduced by way of prosthetic implants and into immunocompromised patients via intravenous catheters.
Rhopalia
Rhopalia are structures of the jellyfish which contain specialized sensory structures. Each rhopalium typically contains organs that detect chemicals, light, touch and equilibrium (orientation).
Ribonucleic acid (RNA)
Ribonucleic acid (RNA) is a nucleic acid composed of a single chain of nucleotides. RNA is needed for protein synthesis and occurs in three forms: (a) messenger RNA, involved in transcription and transport of a coded signal from DNA to ribosomes; (b) ribosomal RNA, forming the site of polypeptide synthesis; and (c) transfer RNA, carrying amino acids to the ribosomes to be inserted in the correct sequence during translation.
RICL
Receiving Inspection Check List
RID
Review Item Disposition
RIG
Rate Integration Gyros
RIM
Refrigerator Incubator Module
RIM
Relational Information Management
RIU
Remote Interface Unit
RMC
Remote Monitoring Center
RMOAD
Reference Mission Operations Analysis Document
RMS
Remote Manipulator System
RMS
Root Mean Square
RNAzol
RNAzol is bioseparation method used to extract RNA material from tissue homogenates or body fluids.
RO
Recurring Operations
Rod
Rod denotes a morphologic type of bacteria.
Roentgen
A roentgen is an international unit of exposure dose of gamma (or X-ray) radiation. In field dosimetry, one roentgen is essentially equal to one rad. It is named for the German scientist and discoverer of X-rays, Wilheim Conrad Roentgen.
Roentgen Equivalent Man (REM)
A Roentgen Equivalent Man (REM) is a unit of radiation dose. Small doses are measured in millirem; one rem = 1,000 millirem.
Roentgenography
Roentgenography is photography with the use of X-rays.
Roentgeonogram
A roentgeonogram is a shadow picture made on a sensitized film or plate by means of X-rays or roentgen rays; it is better known as an X-ray.
Roll
Roll is an angular movement about the front-to-back axis, for example, attempting to touch the ear to the shoulder.
ROM
Read Only Memory
ROM
Rough Order of Magnitude
Root module
The root module of the Svet greenhouse is also called the vegetation module. It is inserted into the bottom of the plant growth chamber and has two sections, or cuvettes, called K1 and K2. Each cuvette has two rows for seed planting. It is filled with a granular substance called Balkanine, which is similar in appearance to kitty litter, and has water and air supplied by a compressor and pump.
Rose bengal agar (RB)
Rose bengal agar (RB) is a sodium salt agar base that is used in the isolation and maintenance of fungi.
Rose bengal medium
Rose bengal medium is a selective medium used for the isolation of yeasts and molds.
Rosette stage
The Rosette stage is an early stage of plant growth. Many plants, when developing, develop leaves first to support photosynthesis, and then develop a stem. During this stage, the plants look like rosettes.
Rotatores
Rotatores are rotator muscles; a number of short transversospinal muscles chiefly developed in the thoracic region.
RPM
Revolutions per Minute
RPS
Rack Power Supply System
RPSDI
Rack Power System Data Interface
RQMTS
Requirements
RR
Requirements Review
RRF
Resources Required Factor
RS/1
Research System/1
RSD
Reentry Systems Division
RSE
Research Support Electronics Branch at Ames Research Center
RSPL
Returned Sample Processing Laboratory
RSS
Root Sum Square
RTC
Real-Time Clock
RTCC
Real-Time Computer Complex
RTG
Radioisotope Thermoelectric Generator
RTN
Return
RTOP
Research Technology Operating Plan
RTRSOC
Real-Time Reporting System on Oceanic Conditions
Rubella
Rubella is the name given to German or three-day measles. It is caused by the rubella virus and is characterized by enlargement of lymph nodes, usually with little fever. High incidence of abnormalities are found in children that are infected during the first several months of fetal life.
Rubeola
Rubeola is a term that has been used as a synonym for two different viral diseases of man, namely measles (morbilli) and rubella. Presently, rubeola is often used as a synonym for measles.
Russian Space Agency (RSA)
The Russian Space Agency (RSA) is the Russian government agency responsible for all Russian space activities, such as launching and maintaining the Mir Space Station.
RV
Requirement Verification
S
Signal Pin Number
S
Similarity
S&LSD
Space and Life Sciences Directorate
S-C
Subcarrier
S/AD
Specification and Assembly Drawing
S/N
Serial Number
S/S
Subsystem
S/W
Software
SA
Solar Array
SA
Support Agency
Sabauraud’s dextrose agar
Sabauraud’s dextrose agar is a culture medium for fungi containing peptone agar and glucose that has the pH adjusted to 5.6; it is the standard, most universally used medium in the field of mycology and is the international reference.
Saccade
A saccade is a rapid, jerky or quick eye movement.
Saccule
The saccule is the smaller of the two membranous sacs within the vestibule of the ear.
Sacrum
The sacrum is the segment of the vertebral column forming part of the pelvis; it is a broad, spade-shaped bone that closes in the pelvic girdle posteriorly.
SAE
Society of Automotive Engineers
SAF fixative
SAF (sodium acetate-acetic acid-formalin) fixative is used to preserve fecal samples.
SAG
Science Advisory Group
SAIS
Space Application Information System
SAIS
Science and Applications Information System
SAL
Scientific Airlock
Saline
(Physiological) saline is an isotonic solution of sodium chloride in water, used for temporarily maintaining living cells.
Saline loading
Saline, or salt loading, is a method used to protect astronauts from orthostatic intolerance (lightheadedness or fainting) when they return to Earth from stays in space, a near-weightless environment. Just before landing, astronauts consume several liters of water and take salt tablets to help their bodies retain the water. This is an attempt to try and counteract the normal adaptive water loss that occurs in microgravity which causes some astronauts to experience orthostatic intolerance when subject to gravity forces.
Saliva
Saliva is a clear, tasteless, odorless, slightly acid (pH 6.8) viscid fluid, consisting of the secretion from the parotid, sublingual, and submaxillary salivary glands and the mucous glands of the mouth. Its function is to keep the mucous membrane of the mouth moist, to lubricate the food during mastication, and in a measure, to convert starch into maltose, the latter action being effected by a diastatic enzyme, ptyalin.
SAR
Synthetic Aperture Radar
SARADAR
Space Radar
Sarcomere
A sarcomere is one of the basic units of a striated muscle which causes it to contract.
SAS
Science Application Software
SATS
Station Accommodation Test Sets
Saturation diving
SB
Serial Byte
SBB
Satellite Busy Box
SC
Subsystem Computer
Scanning electron microscope
A scanning electron microscope is a microscope that forms a three-dimensional image on a cathode-ray tube by moving a beam of focused electrons across an object and reading both the electrons scattered by the object and the secondary electrons produced by it.
SCAPE
Self-Contained Atmospheric Protection Ensemble
Scapula
The scapula is the bone known as the shoulder blade.
SCAS
Subsystem Computer Application Software
SCC
Specification Configuration Chart
SCCM
Standard Cubic Centimeters per Minute
SCD
Specification Control Drawing
SCDAS
Sim-Cage Data Acquisition System
SCI
Science
Scintillation
In nuclear medicine, scintillation describes the light emitted when an X-ray or gamma ray is absorbed by a crystal or liquid radiation detector.
Scintillation counting
Scintillation counting is a technique for measuring the quantity of a radioactive isotope present in a sample. In biology, liquid scintillation counting is mainly used for isotopes such as carbon 14, sulfur 35 and phosphorous 32 and particularly for the low energy emission of hydrogen 3. Gamma emissions are often measured by counting the scintillations that they cause in a crystal. Autoradiographic images can be enhanced by using a screen of scintillant behind the film.
Scintillation detector
A scintillation detector records the flash of light resulting from ionization of a chemical that transforms incident electromagnetic or radioactive energy into light.
SCL
Specification Change Log
Sclerenchyma
Sclerenchyma is a plant tissue in which the cells have greatly thickened walls impregnated with lignin and no cell contents. The tissue has a mechanical function of supporting the plant and consists of two types of cells, fibers and scleroids. Fibers are long cells with tapered ends, which are often grouped into bundles.
SCN
Specification Change Notice
Scopolamine
Scopolamine is a central nervous system depressant used to prevent motion sickness.
Scopolamine
Scopolamine is a drug that prevents muscle spasm by blocking the activity of the neurotransmitter acetylcholine.
SCOS
Subsystem Computer Operating System
SCPR
Support Contractor Purchase Request
SCQ
Science Criteria Questionnaire
SCR
Strip Chart Recorder
SCS
Simulation Control Station
SD
Solar Dynamic
SDAS
Sim-Cage Data Acquisition System
SDC
Sunstrand Data Control, A Manufacturer
SDDS
Simulated Data Display System
SDDU
Simulated Data Display Unit
SDE
Software Development Environment
SDF
Software Development Facility
SDL
Spacelab Data Liaison Engineering
SDM
Science Data Manager
SDR
System Design Review
SDRD
Summary Design Review Document
SDTN
Space and Data Tracking Network
SE
Support Equipment
SE&I
Systems Engineering and Integration
SE-FAC
Support Equipment Facility Plan
SEASAR
Sea Synthetic Aperture Radar
SEB
Source Evaluation Board
SEB
Simulated Experiment Board
Seborrheic dermatitis
Seborrheic dermatitis is a common, chronic, inflammatory skin disease characterized by dry or moist, greasy scales and yellowish crusts. Common sites are the scalp, eyelids, face, external surfaces, or the ears, axillae, breasts, groin, and gluteal folds.
sec
Seconds
SEC
Source Evaluation Committee
Sediment
Sediment is matter which subsides to the bottom, from water or any other liquid.
Sedimentation
Sedimentation is the settling of a component of a mixture under natural or artificial gravitational fields so that the mixture separates into two or more phases or zones.
SEE
Stowed Experiment Equipment
SEFP
Support Equipment Facility Plan
SEI
Simulated Experiment Interface
SEID
Support Equipment Item Description
SEIDS
Support Equipment Item Description Sheet
SEM
Scanning Electron Microscope (System)
Semi-permeable
Semi-permeable means partially but not freely or wholly permeable, e.g. permeable to some usually small molecules but not to other usually larger particles.
Semicircular canals
Semicircular canals are the three bony tubes in the labyrinth of the ear and are associated with balance; they are known as the anterior, posterior and lateral semicircular canals.
Semivolatiles
Semivolatiles are organic compounds that evaporate slowly at standard temperature and pressure (20 degrees Celsius and 1 atmosphere pressure).
Sensing system
A sensing system is one that provides automatic detection of a signal or action.
Sensor
A sensor is a device, such as a photoelectric cell, that receives and responds to a signal or stimulus. Sensors can also refer to single cells or a group of specialized cells which detect a particular stimulus and initiate the transmission of impulses via the sensory nerves.
Sensorimotor (Sensory-motor)
Sensorimotor denotes a nerve possessing both sensory and motor functions.
Sensorimotor controls
Sensorimotor controls are controls of the mixed nerves that contain both sensory and motor fibers (afferent and efferent fibers).
Sensorimotor reactions
Sensorimotor reactions are reactions of the mixed nerves that contain both sensory and motor fibers (afferent and efferent fibers).
Sensory
Sensory relates to the input into the nervous system from the nerve receptors of the body; it is any information carried from receptors throughout the body toward the brain and spinal cord.
Sensory-motor system
The sensory-motor system refers to the interaction of the sensory nerves -- such as those that sense sight, smell and touch -- with the nerves that control muscular movement. Signals from the sensory nerves are sent to the brain where they can be processed to make a specific muscular response.
SEPAC
Space Experiments with Particle Accelerators
Septicemia
Septicemia is a systemic disease caused by the multiplication of microorganisms in the circulating blood.
Serological
Serological means of or relating to serology, the study of blood serum and its constituents, particularly their contribution to the protection of the body against disease.
Serology
Serology is the branch of laboratory medicine that studies blood serum for evidence of infection by evaluating antigen-antibody reactions in vitro.
Serotype
Serotype is a subdivision of a species or subspecies distinguishable from other strains therein on the basis of antigenic character.
Serum
Serum is the fluid portion of the blood; it is essentially similar in composition to plasma but lacks fibrinogen and other substances used in the coagulation (blood clotting) process.
Serum glutamic oxaloacetic transaminase (SGOT)
Serum glutamic oxaloacetic transaminase (SGOT) is a catalytic enzyme found in various parts of the body, especially the heart, liver and muscle tissue. Increased amounts of the enzyme occur in the serum as a result of myocardial infarction, acute liver disease, the actions of certain drugs, and any disease or condition in which cells are seriously damaged.
Serum glutamic pyruvic transaminase (SGPT)
Serum glutamic pyruvic transaminase (SGPT) is a catalytic enzyme normally found in high concentrations in the liver. Greater than normal amounts in the serum indicate liver damage.
Serum-ionized calcium
Ionized calcium is a cation that circulates freely in the bloodstream and comprises 46-50% of all circulating calcium. Only the ionized calcium can be used by the body in such vital processes as muscle contraction, cardiac function, transmission of nerve impulses, and blood clotting. Ionized calcium is considered a more sensitive and accurate indicator for many operative procedures and disease processes. A normal serum ionized calcium for an adult is 4365-5.28 mg/dl.
SERV
Servicing or Service
SESAC
Space and Earth Science Advisory Committee
SET
Source Evaluation Team
SETI
Search for Extraterrestrial Intelligence
Sextant
A sextant is a navigational instrument used for measuring the altitudes of celestial bodies.
SF
Space Flight
SFE
Smart Front-End
SFU
Space Flyer Unit
SGLS
Space Ground Link Station
SGP
Single Ground Point
SGSE
Special Ground Support Equipment
SHe
Super Critical Helium
SHEAL
Shuttle High Energy Astrophysics Laboratory
Shielding
Shielding is a material of suitable thickness and physical characteristics used to protect personnel from radiation.
SHRDM
Simulated High Rate Demultiplexer
SHRM
Simulated High Rate Multiplexer
SI
International System (of Units)
SI
Serial Input
SI
Stimulation Index
SIB
Systems Integration Board
SICD
Stowage Interface Control Drawing
Sigmoidal curve
A sigmoidal curve is a curve in the shape of the letter S or of the Greek letter sigma.
Signal conditioning
Signal conditioning is the process of converting information or data into a form that is better perceived by human beings.
Silastic
Silastic is a rubberlike polymeric silicone material that is soft, pliable and biologically inert.
Silique
A silique is a seed pod of a plant.
SIM
Simulator, Simulation
Simethicone
Simethicone is an antiflatulent and is prescribed to decrease excess gas in the gastrointestinal tract.
Single Event Unit (SEU)
Single Event Unit (SEU) is a single change in the binary code. SEUs can be caused by radiation.
Sinoatrial node (SA node)
The sinoatrial node (SA node or sinus node) is called the "pacemaker" of the heart. It is a microscopic area of cardiac muscle located in the heart. It is connected to the autonomic nervous system and acts to speed up or slow down the heart rate when necessary.
Sintering
Sintering means to heat a powdered substance without thoroughly melting it, causing it to fuse into a solid but porous mass.
Sinus node
The sinus node is also known as the sinoatrial node (SA node); it is called the "pacemaker" of the heart. It is a microscopic area of cardiac muscle located in the heart. It is connected to the autonomic nervous system and acts to speed up or slow down the heart rate when necessary.
Sinusoidal linear acceleration
Sinusoidal linear acceleration is forward spiral or helical movement.
SIO
Serial Input-Output
SIP
Standard Interface Plan
SIP
Screen Input Processor
SIPS
Spacelab Input Processing System
SIPS
Small Instrument Pointing System
SIR
Scientific Information Retrieval
SIRTF
Space Infrared Telescope Facility
SK
Servicer Kit
SKB
Simulated Keyboard
Skeletal muscle
Skeletal muscles are muscles that connect bones together.
Skeletal system
The skeletal system is the system of interconnecting bones that form the rigid framework of the human body. The skeletal system not only provides the body with form, but also protects and supports its soft organs and tissues. It also provides attachment sites for muscles and serves as a system of levers essential for locomotion.
Skin conductance
Skin conductance is a measure of the electrical conducting power of the skin surface.
SL
Spacelab
SL-1
Spacelab Mission One
SL-3
Spacelab Mission Three
SL-4
Spacelab Mission Four
SLASER
Space Laser
SLDPF
Spacelab Data Processing Facility
Sleep
Sleep is a physiologic state of relative unconsciousness and inaction of the voluntary muscles, the need for which recurs periodically. Sleep is divided into two distinct states known as non-rapid eye movement sleep (NREM) and rapid eye movement sleep (REM). These two states occur in a roughly 90 minute cycle that is repeated 5 to 6 times a night and includes four stages of NREM sleep, and REM.
Sleep latency
Sleep latency is a common measure of sleep quality. It is latency or, simply, the amount of time required to fall asleep after the beginning of the rest period.
Sleep stage
Sleep is divided into two distinct states known as non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. These two states occur in a roughly 90-minute cycle that is repeated 5 to 6 times a night. NREM sleep has four stages, which can be distinguished by brain wave patterns in electroencephalograms (EEGs) and other characteristics. As we fall asleep, we enter the transition sleep called stage 1 and begin our first "sleep cycle." Within a few minutes we begin our "baseline" sleep called stage 2, which occupies approximately 45-60% of our sleep time. Within 15-20 minutes we have entered stage 3 sleep, which is followed by stage 4, often called delta sleep or slow-wave sleep because of the very high voltage, slow brain waves that characterize it. Respiration and heart rate slow and the body is almost immobile. After 20-30 minutes of slow-wave sleep, we lighten into stage 2 and almost immediately change gears into a very active brain-wave pattern known as paradoxical or REM sleep. Simultaneously, respiration and heart rate increase substantially, and we lose our ability to use our postural or skeletal muscles. Also, our brain becomes so activated that we start to hallucinate and experience what we call dreams. Our eyes begin to move sporadically, often in relation to what we are dreaming. In effect, we are a highly activated brain in a paralyzed body. This paradoxical state will last 10-20 minutes and then we return to stage 2 again. As we proceed through several sleep cycles, some delta sleep time is replaced with longer periods of alternating stage 2 and REM sleep. By the final sleep cycle of the night, we spend approximately half our time in stage 2 and half in REM sleep.
Slice
In MRI, a section or “slice” of the body is often imaged. The slices are put together to form a complete picture.
SLIPS
Shuttle and Life Sciences Implementation Plans and Status
Slow-twitch
Slow-twitch describes a muscle fiber that contracts slowly, especially during sustained physical activity requiring endurance.
Slow-twitch fiber
Slow-twitch muscle fibers generate force for prolonged, continuous activity; they are most active in resisting gravity and are important in maintaining posture.
Slow-twitch muscle fiber
Slow muscle fibers are smaller than fast muscle fibers, and, unlike fast-twitch muscle fibers, they use oxygen, do not have much strength in contraction, but are very resistant to fatigue, thus they are used for activities such as distance running or endurance events.
SLS
Spacelab Life Sciences
SLS-1
Spacelab Life Sciences-1
SLSAL
Space Life Sciences Archival Library
SLSPO
Space Life Sciences Projects Office
SM
Service Module, Short Module, Spectrometer Module
SM
Squirrel Monkey
SM
Short Module
SM
Spectrometer Module
SMA
Science Monitoring Area (POCC)
SMA
Spectrometer Module Assembly
SMACR
Science Monitoring Area Computer Room
Small intestine
The small intestine is divided into the duodenum, jejunum, and ileum. It is here that most of the processes of digestion and absorption of food take place.
Smallpox
Smallpox is an acute, highly infectious viral disease initially characterized by chills, high fever, and backache, with subsequent widespread eruption of pimples that eventually blister, produce pus, and form pockmarks.
SMCC
System Mission Control Center
SMD
Spacelab Mission Development
SMIP
Spacelab Mission Implementation Plan
SMMI
Small Mass Measurement Instrument
SMMO
Spacelab Mission Management Office
Smooth pursuit tracking
Smooth pursuit tracking is the type of eye movement that occurs when the eyes follow and track a single distinct target that is in motion.
SMR
Science Measurement Requirements
SMRBQT
Squirrel Monkey RAHF Biocompatibility Quality Test
SMRS
Squirrel Monkey Restraint System
SMS
Service Manipulator System
SMT
Squirrel Monkey Test
SN
Serial Number
SN
Space Network
SO
Serial Output
Soak
A soak in lower body negative pressure (LBNP) studies is exposure of subjects to moderate negative pressure for a long period (hours). Heart rate and blood pressure are usually monitored.
Sodium (Na)
Sodium is a soft grayish metal in the alkaline metals group and is one of the most important elements in the human body. Sodium ions are involved in acid-base balance, water balance, the transmission of nerve impulses, and the contraction of muscles.
Sodium urate
Sodium urate is a substance in crystal form found in the urine, blood, and some tissues in the body.
SOFI
Spray-On Foam Insulation
SOHO
Solar Heliosphere Observatory
Solar inertial mode
Solar inertial mode is the mode of navigation whereby a spacecraft is directed towards the sun using inertial detectors, which automatically provide vehicle position, heading, and velocity.
Solar particle event
A solar particle event is a burst of energetic ions (typically protons) from a solar flare site or a coronal mass ejection. These events may disrupt long-distance radio communications on Earth and deteriorate satellite orbits. Very energetic particles can endanger astronauts or destroy satellite electronics.
Solar surface eruptions
Solar surface eruptions are caused by particles or objects colliding with the solar surface. The particles can sometimes cause solar flares, which consist of protons and alpha particles, to shoot into outer space.
Solenoid
A solenoid is a coil of insulated or enameled wire wound on a rod-shaped form made of solid iron, solid steel, or powdered iron.
Soleus
The soleus is the broad, flat muscle located in the lower leg, beneath the calf muscle, that flexes the foot so that the toes point downward.
Solid Sorbent Air Sampler (SSAS)
The Solid Sorbent Air Sampler (SSAS) is a device used for capturing chemical contaminants which consists of 8 sorbent tubes and a pump assembly in a cylindrical outer case. The pump assembly is battery powered and helps draw air through a sample tube which absorbs the chemical contaminants.
Solid-phase radioimmune inhibition assay
The solid-phase radioimmune inhibition assay measures the concentration of a biomolecule by the degree of displacement of the radioactive form, preventing it from forming complexes with the solid-phase anti-immunoglobulin.
Solidification
Solidification is the process of changing the state of matter from a liquid to a solid, such as water changing to ice.
Somatic
Somatic refers to the non-productive parts of a body.
Somatoliberan
Somatoliberan, a decapeptide released by the hypothalamus, is a growth hormone-releasing factor that induces the release of human growth hormone (somatotropin).
Somatosensory cortex
The somatosensory cortex is the area of the cerebral cortex of the brain to which the sensory signals are sent. The somatic senses include vision, hearing, taste, smell and equilibrium.
Somatosensory receptors
Somatosensory receptors are single nerve endings which allow the brain to have superficial and deep body sensations.
Somatotropin
Growth hormone (or somatotropin) is an anterior pituitary hormone that causes growth of almost all cells and tissues of the body.
SOMS
Shuttle Orbiter Medical System
SOP
Standard Operating Procedures
SOPS
Spacelab Output Processing System
Sorbent
Sorbent refers to the property of a substance that allows it to interact with another compound, usually making it bind.
SORC
Science Operations Remote Center
South Atlantic Anomaly (SAA)
The South Atlantic anomaly (SAA) is a region of intense radiation from protons trapped in the part of the Van Allen radiation belts lying closest to the earth's surface. The SAA arises primarily because the earth's magnetic field is offset from its center. Over this region, the geomagnetic field draws particles closer to the Earth than in other regions of the belts. The South Atlantic anomaly is located over a large portion of South America, the South Atlantic and the southern tip of Africa.
SOW
Statement of Work
SP
Space Platform
SP&R
Safety Policy and Requirements Document (NHB 1700.7A)
SPA
Software Product Assurance
Space Adaptation Syndrome (SAS)
Space Adaptation Syndrome (SAS), also called space motion sickness, is a syndrome that afflicts about half of all space travelers. Symptoms, which resemble those of motion sickness on earth, range from minor (nausea and headaches) to severe (vomiting) and vary from person to person. Although, the exact cause is unknown, SAS is believed to be caused by conflicting sensory inputs from the eyes, inner ear (vestibular system) and tactile senses (touch).
Space motion sickness (SMS)
Space motion sickness (SMS), or Space adaptation syndrome (SAS), is a syndrome experienced by space travelers that is similar to motion sickness on earth (air sickness, car sickness, sea sickness), causing nausea, dizziness and sometimes vomiting. Space motion sickness affects about 60% of the people who travel in space with varying degrees of severity.
Spacehab
Spacehab is a pressurized module designed to be attached to the Orbiter middeck. Smaller in size than the Spacelab, it provides approximately 1100 cubic feet of additional volume for support of crew and experiments. It is connected to the Space Shuttle by a modified tunnel adapter, and draws resources such as cooling, power, data and housekeeping systems from the Shuttle's cabin and cargo bay/payload support provisions. The Spacehab module can accommodate various quantities and sizes of equipment, hardware lockers, and racks.
Spacelab
Spacelab is a reusable laboratory that contains space flight hardware carried in the Space Shuttle’s payload bay. Most life sciences experiments are conducted in the Spacelab. Equipment is mounted along the walls and floor of the pressurized cylindrical Spacelab module. Crewmembers float into the Spacelab through a tunnel adapter that transits from the airlock in the Shuttle middeck to the Spacelab.
Spacelab Middeck Experiments (SMIDEX)
The Spacelab Middeck Experiments (SMIDEX) facility flew for the first time on SLS-1. The rack contained five experiments originally designed to fly in the Shuttle middeck. An advantage of flying SMIDEX on SLS-1 was that it offered additional flight opportunities for the backlog of experiments waiting to fly in the Shuttle middeck.
SPAD
Subsystems Positioning Aid Devices
SPAF
Single Pass Auxiliary Fan
SPAH
Spacelab Payload Accommodation Handbook
SPAH
Space Physics Analysis Network
SPAN
Space Physics Analysis Network
SPAN
Spacelab Payload Accommodation Handbook
SPARTAN
Shuttle-Pointed Autonomous Research Tool for Astronomy
Spatial
Spatial is relating to space or a space.
Spatial orientation
Spatial orientation refers to the process of aligning or positioning in a three-dimensional space with respect to a specific direction or reference system.
SPDA
System Payload Data Analysis
SPDM
Special Purpose Dexterous Manipulator
Spec
Specifications
Species
A species is a fundamental category of taxonomic classification ranking after genus and consisting of organisms capable of interbreeding.
Specific gravity
Specific gravity is the ratio of a solid or liquid to the mass of an equal volume of distilled water at 4 degrees Celsius or of a gas to an equal volume of air or hydrogen under prescribed conditions of temperature and pressure.
Spectral
Spectral means relating to or produced by a spectrum, the distribution of energy emitted by a radiant source.
Spectrometer
A spectrometer is any instrument used for measuring the intensity and wavelengths of visible or invisible electromagnetic radiation.
Spectrophotometer
A spectrophotometer is an instrument for measuring the intensity of light of a definite wavelength transmitted by a substance or a solution, giving a quantitative measure of the amount of material in the solution absorbing the light; a colorimeter with a choice of wavelength and photometric measurement.
Spectroreflectometer
A spectroreflectometer is a type of light measuring device that measures the quantity and color of light reflected from a surface.
Spectrum analyzer
A spectrum analyzer is an instrument used to analyze the frequency content and characteristics of a signal.
SPELL
A DEC Tape to Monitor Spelling in Standard Formatted Text File
SPEX
Space Plasma Experiment
SPF
Specific Pathogen Free
SPG
Single Point Ground
Spherocyte
A spherocyte is a red blood cell that exhibits a small, round dense spherical shape.
SPIAP
Shuttle Payload Integration Activities Plan
SPICE
Spacelab Payload Integration & Coordination in Europe
SPIDPO
Shuttle Payload Integration Development Program Office
Spin-spin relaxation time (T2)
In magnetic resonance imaging (MRI), the spin-spin relaxation time (abbreviated as T2) is the time required for the transverse magnetization of hydrogen atoms to return to equilibrium. Every tissue in the human body has its own T2 value. Therefore, T2 can be used to differentiate between different tissue types (e.g., fat and muscle) and detect pathological changes in tissue (e.g., edema in sore muscles). A T2 weighted image will have a bright water signal.
Spinal bone marrow
Spinal bone marrow is the tissue that is inside the cavities of the bones of the spine.
Spinal cord
The spinal cord is the portion of the central nervous system enclosed in the vertebral column, or back, consisting of nerve cells and bundles of nerves connecting all parts of the body with the brain.
Spinalis
Spinalis is a spinal muscle; the medial component of the erector spinae muscle; it is comprised of musculus spinalis capitis, m. spinalis cervicus and m. spinalis thoracis.
SPIPAY
Payload Integration Office
Spirometry
Spirometry is making pulmonary measurements with a spirometer, an instrument used for measuring respiratory gases.
Spleen
The spleen is a large dark-red egg-shaped organ situated on the left side of the body below and behind the stomach. It is a blood-forming organ in early life and a storage organ for red blood cells. It also acts as a blood filter.
Splenic trapping
Splenic trapping refers to the ability of the spleen to temporarily sequester red blood cells.
SPM
Solar Power Module
Spongy (cancellous, trabecular) bone
Spongy bone, also called cancellous or trabecular bone, consists of an irregular lattice of thin plates of bone called trabeculae. The spaces between the trabeculae of some bones are filled with red marrow, which produces blood cells. Spongy bone makes up most of the bone tissue of short, flat, irregularly shaped bones and most of the epiphyses of long bones.
Spore
A spore is a reproductive, usually unicellular body produced asexually by plants and some invertebrates.
SPP
Solar Physics Payload
SPPO
Spacelab Payload Project Office
SPR
System Problem Report
SPS
Samples per Second
SPS
Science Processing Subsystems
SPSME
Spacelab Payload Standard Modular Electronics
Squall line
A squall is a brief, sudden and violent windstorm often accompanied by rain or snow. A squall line is a group of squalls moving together often preceding a front of cold air moving into a warmer area.
SR&QA
Safety, Reliability and Quality Assurance
SR&T
Supporting Research and Technology
SRA
Support Requirements Analysis
SRAM
Static Random Access Memory
SRAU
Simulated Remote Acquisition Unit
SRB
Solid Rocket Booster
SRB
Software Review Board (ARC)
SRB
Service Request Block
SRC
Source
SRD
Science Requirements Document
SRI
Stanford Research Institute in Menlo Park, CA
SRP
Standard Repair Procedure
SRR
System Requirements Review
SRT
Science Research and Technology
SRV
Service Recovery Vehicle
SS
Staff Scientist
SSCB
Space Station Control Board
SSCBD
Space Station Control Board Directive
SSCN
Space Station Change Number
SSD
Spacecraft Software Division
SSDPF
Spacelab System Data Processing Facility
SSDS
Space Station Data System
SSE
Software Support Environment
SSIP
Shuttle Student Involvement Program
SSIS
Space Station Information System
SSME
Space Shuttle Main Engine
SSMI
Special Sensor Microwave Imager
SSP
Space Station Program
SSPE
Space Station Program Element
SSPF
Space Station Processing Facility
SSPO
Space Station Program Office
SSPP
Space Station Program Participant
SSR
Science Status Review
SSRB
Senior Safety Review Board
SSSC
Space Station Support Center
SSSP
Space Station Science Plan
ST
Space Telescope
STA
Shuttle Training Aircraft
Sta
Station
Stable isotope
A stable isotope is a nonradioactive form of a chemical element. It has the same atomic number as other forms of the element, but different isotopes have different atomic masses.
Stage 1 sleep
Stage 1 sleep is experienced as the body is falling to sleep. It is a transition stage between wake and sleep. It usually lasts between 1 and 5 minutes and occupies approximately 2-5 % of a normal night of sleep. This stage is dramatically increased in some cases of insomnia and in disorders that produce frequent awakenings.
Stage 2 sleep
Stage 2 sleep is the second stage of non-rapid eye movement sleep and is the "baseline" of sleep; it is from stage 2 that the other three sleep stages emerge. Stage 2 occupies approximately 45-60% of sleep.
Stage 3 and 4 (delta) sleep
Sleep stages 3 and 4 are stages of non-rapid eye movement sleep. Stage 4 is often called "delta" sleep or "slow-wave" sleep because brain activity slows dramatically. Contrary to popular belief, delta sleep (not rapid eye movement sleep) is the "deepest" stage of sleep and the most restorative. It is delta sleep that a sleep-deprived person's brain craves the most.
Stand test
A stand test allows researchers to measure a person's response to standing, to better understand how gravity affects the heart and blood vessels before and after space flight. When people stand upright, gravity stresses the heart by moving blood from the chest and head to the lower body.
Standard deviation
The standard deviation is a measurement of variation in a data set.
Stannous fluoride
Stannous fluoride is a white powder, SnF2, used to fluoridate toothpaste.
Staphylococcus
Staphylococcus is a genus of nonmotile, nonsporeforming, aerobic to facultatively anaerobic bacteria, with gram-positive, spherical cells. They are found on the skin, in skin glands, and on the nasal and other mucous membranes of warm-blooded animals, and in a variety of food products.
Star Tracker
The Star Tracker is an electro-optical tracking device used while the Shuttle is in orbit to align it with other objects, as well as to track targets, such as the Mir. These functions support the docking of the Shuttle to the Mir.
Starch
Starch is a polysaccahride made up of glucose residues that exists in most plant tissues. It is also found in the human body in saliva and pancreatic juice. It is used as a dusting powder, an emollient and an ingredient in medicinal tablets and is an important raw material for the manufacture of alcohol, acetone, butanol, lactic acid, citric acid and glycerine.
Starch granule amylose
A starch granule amylose is a polysaccharide made up of glucose residues that exists in most plant tissues.
STARPAC
Space Technology Applied to Rural Papago Advanced Health Care
Static
Static means 1) involving no variation with time, or 2) involving no movement
Static hand grip test
The static hand grip test is an isometric exercise where the subject squeezes a hand grip until the arm is fatigued (approximately 2 minutes). When the arm is fatigued, a cuff on the upper arm is inflated for 2 minutes.
Statolith
A statolith is a crystal found in the ear, and is made up of particles of calcium carbonate and protein. Present in man, animals, and plants, they are responsible for the sense of equilibrium.
STD
Standard
STDN
Spaceflight Tracking and Data Network
STE
Special Test Equipment
Steady-state
Steady-state refers to a stable condition that does not change over time or in which change in one direction is continually balanced by change in another.
Stellate cell
Stellate cells (or stellate ganglion) are star-shaped nerve cell bodies in the base of the neck, from which sympathetic nerve fibers are distributed to the face and neck and to the blood vessels and organs of the upper body.
Stellate ganglion
Stellate ganglion (or stellate cells) are star-shaped nerve cell bodies in the base of the neck, from which sympathetic nerve fibers are distributed to the face and neck and to the blood vessels and organs of the upper body.
Stereology
Stereology is the study of the three-dimensional aspects of a structure.
Stereophotogrammetry
Stereophotogrammetry refers to measurements made on the position or shape of a figure in a photograph.
Stereoscopic
A stereoscopic view is a type of optical view which creates a three-dimensional effect by using two photographs of the same scene taken at slightly different angles and viewed through two eyepieces.
Sterile
Sterile means free from any bacteria or other microorganisms.
Sternal
Sternal means of or pertaining to the sternum; in the region of the sternum. Commonly referred to as the breast bone, the sternum is the broad, flat bone located over the heart, to which the ribs attach.
Sternum
The sternum is the breastbone, the bone in the front of the chest that articulates with the ribs.
Steroid
Steroid is any of a large number of hormonal substances with a similar basic chemical structure, produced mainly in the adrenal cortex and gonads.
Stimuli
A stimulus (plural stimuli) is a change in the external or internal environment of an organism that provokes a physiological or behavioral response in the organism.
STL
Support Team Leader
STO
Solar Terrestrial Observatory
Stomach awareness
Stomach awareness is a general feeling of mild discomfort in the stomach, usually described as “upset stomach."
Stomatal conductance
Stomatal conductance is a numerical measure of the rate of passage of either water vapor or carbon dioxide through the stomata, or small pores, of the plant.
Stomatocyte
A stomatocyte is a red blood cell that has a single concavity appearance.
Stow
On a spacecraft, to stow means to put away securely, usually in a locker.
Stowage
Stowage is material that has been put away securely, usually in lockers if the material is on a spacecraft. It is also the act or process of stowing, or the state of being stowed.
STP
Special Test Procedure
Strain
A strain is a race or stock; in bacteriology, the set of descendants that originates from a common ancestor and retains the characteristics of the ancestor.
Strain gauge
A strain gauge is a device in which mechanical motion is converted into an electric variation that is used as a sensitive measure of strain.
Strain-gage technique
The strain-gage technique is a method used to measure the change in circumference of a body part. Typically, the strain-gage is a thin, mercury-filled device placed (strapped) around the area to be measured. As the circumference of the body part changes, a measurement reading is observable on this highly sensitive device.
Streptococcus
Streptococcus is a genus of nonmotile (with few exceptions), nonsporeforming, aerobic to facultatively anaerobic bacteria containing Gram-positive, spherical or ovoid cells, that occur in pairs or chains. These organisms occur regularly in the mouth and intestines of man and other animals.
Strip chart recorder
A strip chart recorder converts the electrical signal generated by any measurement, such as the beating of the heart or respiration rate, into a written record using an ink pen and a moving strip of paper.
Stroke volume
Stroke volume is the volume of blood - normally about 70 ml - ejected from the heart into the aorta during the contraction of the ventricles (systole).
Struvite
Struvite is a mineral composed of magnesium ammonium phosphate, crystals of which are present in some renal stones (kidney stones).
STS
Space Transportation System
STT
Spacelab Transfer Tunnel
STU
System Test Unit
Student-Newman-Keuls test
The Student-Newman-Keuls multiple comparisons test is one of the post-hoc statistical tests. After a repeated measures analysis of variance test has revealed that data from 3 or more time points are significantly different, a Student-Newman-Keuls test may be performed to more precisely locate the difference.
Sty
A sty is an infection of a sebaceous gland of the eyelid, often caused by a staphylococcal organism.
Subclinical
Subclinical denotes a period prior to the appearance of manifest symptoms in the evolution of a disease.
Sublimate
Sublimate is to cause a substance (solid or a gas) to change state without becoming a liquid.
Submaximal
Submaximal means less than maximum. Submaximal exercise requires less than one's maximum oxygen uptake, heart rate, or anaerobic power. Usually refers to intensity of the exercise, but may be used to refer to duration.
Submicron
Submicron refers to any object measuring smaller than one micron, a unit equal to one-millionth of a meter.
Submicroscopic
Submicroscopic means too small to be seen in an ordinary light microscope.
Substansia nigra
The substansia nigra is a large cell mass in the midbrain which is a functional part of the basal ganglia system involved in the regulation of voluntary movements at a subconscious level. Destruction or dysfunction of the substansia nigra is associated with Parkinson's Disease.
Subungual hematoma
A subungual hematoma is a collection of blood beneath a nail that usually results from trauma.
Succinate dehydrogenase (SDH)
Succinate dehydrogenase catalyzes the removal of hydrogen from succinic acid and converts it into fumaric acid. Succinate occurs in living organisms as an intermediate in metabolism, the process of energy production and expenditure.
SUG
Software User's Guide
Sulfate
Sulfate is a salt of sulfuric acid. Natural sulfates, such as sodium sulfate, calcium sulfate, and potassium sulfate, are plentiful in the body.
Sulfur-35
Sulfur-35 is a radioactive sulfur isotope used as a tracer in study of metabolism of cystein, cystine, methionine, etc.
Superconducting
Superconductivity is the flow of electric current without resistance in certain metals and alloys at temperatures near absolute zero.
Superconductor
A superconductor is based on the conduction of high levels of electrical current through a specially made material that is kept at very low temperatures. The low temperature keeps the conductor’s resistance low to allow for increased current passage.
Superexcitability
Superexcitability refers to an increased excitability in muscle cell or nerve fibers. In neurophysiology, excitability refers to the triggering of a conducted impulse in the membrane of a muscle cell or nerve fiber. During excitation, a polarized membrane becomes momentarily depolarized and an action potential is set up.
SUPERMG
Superconducting Magnetic
Supernatant
Supernatant is the clear fluid which, after the settling out of an insoluble liquid or solid by the action of normal gravity or centrifugal force, takes up the upper portion of the contents of a vessel.
Supersaturation
Supersaturation is the condition of a solution in which enough solute is present to precipitate out of solution, but other conditions prevent precipitation. Supersaturation of urine occurs when the level of a substance dissolved in it is enough to form urinary calculus.
Supine
Supine denotes the body while lying on the back, face upward.
Suppuration
Suppuration is the formation of pus.
Supraventricular
Supraventricular means situated or occurring above the ventricles, especially in an atrium or atrioventricular node.
SUSIM
Solar Ultraviolet Spectral Irradiance Monitor
SV
Sievert
SVC
Supervisor Call
Svc
Service
Svet
Svet is the Russian word meaning light. It is also the name given to the Russian greenhouse, where plants are grown on the Mir station.
SVO-ZV Dispenser
The SVO-ZV is the source of recycled, non-potable (non-drinkable) water on the Mir Space Station which is used for sanitary purposes.
SVOP
SVOP is the acronym for System for Venous Occlusion Plethysmography, hardware used for experiments performed on the Spacelab Life Sciences-1 Shuttle mission.This item detects changes in the circumference of the arm or calf in response to venous occlusion, using the venous occlusion plethysmography technique.
SVOP
System for Venous Occlusion Plethysmography
SVT
Science Verification Test
SW
Serial Word
SW
Software
SW
Shortwave
sw
Switch
Swab
To swab is to use a small piece of absorbent material on the end of a stick or wire to obtain mucus or other specimen, cleanse and area, or apply medicine.
Sway
Sway is slow movement from an upright to a leaning position. It is a sign of unstable posture.
Sway bar
A sway bar is a rod oriented horizontally and attached to a potentiometer and to the subject being tested in a posturography system. Sway bars are used to measure front-and-back movement of the body. They are usually attached to the subject at the hip and shoulder.
SWB
Surgical Work Bench
SWG
Science Working Group
Sympathetic
Sympathetic means relating to the actions of the sympathetic nervous system, one of the two divisions of the autonomic nervous system. Its nerves are distributed to the blood vessels, sweat glands, salivary glands, heart, lungs, intestines and other abdominal organs, and the genitals. Sympathetic stimulation causes excitatory effects in some organs but inhibitory effects in others.
Symptomatology
Symptomatology is the science of the symptoms of disease, their production and the indications they furnish.
Synapse
A synapse is the tiny gap across which nerve impulses pass from one neuron (nerve cell) to the next.
SYNC
Synchronous or Synchronization
Synchronous discharges
Synchronous discharges are excitations of nerve or muscle fibers that occur at the same time.
Syncopal
Syncopal relates to syncope. Syncope (commonly referred to as fainting) is a loss of consciousness induced by a temporarily insufficient flow of blood to the brain. It occurs in otherwise healthy people and may be caused by an emotional shock, by standing for prolonged periods, by injury or by profuse bleeding. An attack comes on gradually, with lightheadedness, sweating and blurred vision. Recovery is normally prompt and without any persisting ill effects.
Syncope
Syncope (commonly referred to as fainting) is a loss of consciousness induced by a temporarily insufficient flow of blood to the brain. It occurs in otherwise healthy people and may be caused by an emotional shock, standing for prolonged periods, injury or profuse bleeding. An attack comes on gradually, with lightheadedness, sweating and blurred vision. Recovery is normally prompt and without any persisting ill effects.
Syndrome (symptom complex)
A syndrome, or symptom complex, is a number of symptoms occurring together that present a clinical picture of a disease or inherited abnormality.
Synergism
Synergism refers to the act of working together to produce or enhance an effect.
Synthesis
Synthesis is the process of forming compounds out of simpler elements.
Syphilis
Syphilis is a sexually transmitted disease caused by the spirochete, Treponema pallidum, characterized by progression through three stages: local formation of chancres, ulcerous skin eruptions, and systemic infection leading to general paresis.
SYS
System
Systemic
Systemic means relating to a system or affecting the body generally.
Systole
Systole is the phase of the heart beat during which the heart contracts, causing the blood within to be ejected.
Systolic blood pressure
Systolic blood pressure is the blood pressure measured when the ventricles of the heart are contracting.
Systolic time interval
The systolic time interval, also called electromechanical systole, is the Q-S interval; the period from the beginning of the QRS complex to the first vibration of the second heart sound.
T
Test
T-0
T Minus Zero, Time of Launch
T-4
4 Hours Prior to Launch
T-lymphocyte (T-cell)
T-lymphocytes, or T-cells, play an important role in human immunity. They are formed in the thymus gland and react highly specifically against the particular type of antigen (foreign, potentially dangerous substance in the body) that initiated their development.
T-M
Telemetry
T-suppressor cell
T-suppressor cells are white blood cells that specifically suppress immune responses. They are believed to regulate the activities of the other types of T-cells, keeping them from causing excessive immune reactions that might be severely damaging to the body. T-suppressor cells can act on either T-cells or B-cells and play a continuous role in immunological regulation.
T-test
A t-test is a statistical method analogous to determine whether there are differences between two means or between a target value and the calculated mean; the formula for the t-test is the standard deviation for sample sizes of less than 30 cases divided by the deviation from the mean.
T/C
Test Conductor
T12
T12 is the twelfth thoracic vertebra.
TA
Teleoperator Assembler
Tachycardia
Tachycardia is the rapid beating of the heart, usually applied to rates over 100 beats per minute.
Tactile
Tactile refers to the sense of touch.
TAIM
Technical Area Integration Manager
Talus
The talus is the largest of the seven bones that compose the ankle.
Tangent
Tangent means touching at a single point. In geometry, tangent means specifically meeting a curve or surface at a point and having at that point the same direction as the curve or surface. For example, a line may be tangent to a curve, a curve tangent to a surface, and two surfaces tangent to each other. A tangent plane is a plane that touches a surface in a point or line.
Tantalum
Tantalum is a gray ductile metal with a high melting point and excellent corrosion resistance against certain chemicals. Its use as electronic capacitors and filaments in increasing. Tantalum melts at 2415-degrees F and has the chemical symbol Ta.
Target
A target is a display placed in front of a test subject during a neurosensory experiment. This target usually has several LEDs (small lights called light emitting diodes) spread over the display. When one of the LEDs lights up, the test subject has to point to it with a laser beam. The laser itself is fixed on the forehead or on top of the head of the test person, so he/she has to move the head to point to the target. These types of experiments are used to determine reaction time and coordination.
Target acquisition
Target acquisition is the location of an object by vision.
Taurine
Taurine is a crystallizable substance formed by the decomposition of taurocholic acid, which occurs as a constituent of bile.
TBA
To Be Announced
TBD
To Be Determined
TBH
To Be Hired
TBR
To Be Resolved
TBS
To Be Supplied
TC
Test Conductor
TCA
Test Control Area
TCB
TMIS Control Board
TCC
Trace Containment Control
TCDT
Timeline Countdown Test
TCP
Test Checkout Procedures
TCP/IP
Transfer Control Program/Internet Protocol
TCS
Thermal Control Subsystem
TCS
Thermal Control System
TCTO
Time Compliance Technical Orders
TD
Technical Directive
TDAS
Tracking and Data Acquisition Satellite
TDASS
Tracking and Data Acquisition Satellite System
TDM
Time Division Multiplexer
TDMA
Time Division Multiplexer Access
TDP
Test Data Package
TDRS
Tracking and Data Relay Satellite
TDRSS
racking and Data Relay Satellite System
TDY
Temporary Duty
Teflon
Teflon is a man-made plastic from tetrafloroethylene. It can range in use from an impervious coating to a fabric.
Telemeter
Telemeter means to transmit or receive data from a remote location.
Telemetrically
Telemetrically pertains to telemetry, the science of sensing and measuring information at some remote location (spacecraft) and transmitting the data to a convenient location for reading or recording (ground station).
Telemetry
Telemetry is the science and technology of automatic transmission and acquisition of data from remote locations.
Telencephalon
The telencephalon is the part of the embryonic brain that develops into the forebrain, which contains the cerebral hemispheres, olfactory lobes, pineal gland, pituitary gland and optic chiasma.
TEM
Transmission Electron Micrograph
TEMP
Temperature
Temporal
Temporal means relating to time.
TEMS
Transport Environment Monitoring System
Tendon
A tendon is a thick strand or sheet of tissue that attaches a muscle to a bone. Tendons consist of collagen fibers and are therefore inelastic: they transfer the force exerted by muscular contraction, acting to move parts of the body.
Tension
Tension is the act of stretching or the condition of being stretched, or a force tending to produce elongation or extension.
Terrestrial
Terrestrial means originating from the Earth.
Testosterone
Testosterone is a principal male sex hormone. Though this hormone normally (and necessarily) occurs in small amounts in females, it is chiefly known as the hormone responsible for stimulating the development of male sex organs and male secondary sexual characteristics, e.g. facial hair, deepening of the voice, and muscle development.
Tetanic
Tetanic means relating to tetany, a condition of physiologic calcium imbalance marked by tonic spasm of voluntary muscles and often associated with deficient parathyroid hormone secretion, or the disease tetanus.
Tetanus
Tetanus is an acute, often fatal infectious disease caused by a bacillus, Clostridium tetani, that generally enters the body through wounds, characterized by rigidity and spasmodic contraction of the voluntary muscles.
Tether
Tether means to tie or attach. Tethers are used in space to secure astronauts as they work outside their spacecraft.
TEU
Thermal Electric Unit
TEU
Thermoelectric Unit
TFDU
Thin Film Deposition Unit
TFE
Polytetrafluorethylene
TFJ
Tibio Fibular Junction
TGA
Trace Gas Analyzer
Therapeutic
Therapeutic means having healing or curative powers.
Thermistor
A thermistor is a device used to determine temperature.
Thermocouple
A thermocouple is a thermoelectric couple used to measure temperature differences.
Thermoluminescent
Thermoluminescent describes a luminescence produced in a solid as the temperature of that solid is raised as a result of exposure to ionizing radiation.
Thermoluminescent dosimeter
A thermoluminescent dosimeter is a small device used to measure radiation, which is done by measuring the amount of visible light emitted from a crystal in a detector when exposed to ionizing radiation.
Thermophilus
Thermophilus pertains to a thermophile, which is an organism that grows best at a temperature of 50 degrees C.
Thermoregulation
Thermoregulation is the process of regulating body temperature.
Thermostabilized
Thermostabilized is the property by which an object is not readily subject to alteration or destruction by heat.
Thioglycolate broth
Thioglycolate broth is a culture medium that promotes favorable conditions for the growth of anaerobic bacteria.
Thoracic
Thoracic means relating to the thorax, the upper part of the trunk between the neck and abdomen.
Thoracic blood volume
The thoracic blood volume is the volume of blood located in the thorax. The thorax is the upper part of the trunk between the neck and the abdomen (the chest).
Thoracolumbar
Thoracolumbar relates to the thoracic and lumbar areas of the vertebral column.
Thorax
The thorax is the upper part of the trunk between the neck and the abdomen; the chest.
Thrombolytic
Thrombolytic means breaking up or dissolving a clot in the cardiovascular system.
Thrombosis
Thrombosis is a condition in which the blood changes from a liquid to a solid state within the blood vessel and produces a blood clot or thrombus.
Thromboxane
Thromboxane is a substance made by platelets that causes blood clotting and constriction of blood vessels. There are two thromboxanes. Thromboxane A2 (TXA2) is active but is very unstable and has a half-life of only 30 seconds before it undergoes hydrolysis to form thromboxane B2 (TXB2) which is inactive. The thromboxanes are derived from arachidonic acid and are related to prostaglandin.
Throughput
Throughput is the output or production of a computer program over a period of time.
Throw mass
Throw mass is a weight inside some types of stabilizer. The weight can be moved ("thrown") by a motor to change the effective weight of the structure to which the stabilizer is attached. Generally several stabilizers, each with its own throw mass, are used together to stabilize a structure that can be moved in different directions.
Thymus gland
Thymus gland is an organ in the base of the neck, above and in front of the heart. The thymus is enclosed in a capsule and divided internally by cross walls into many lobules, each full of T-lymphocytes (white blood cells associated with antibody production). T-lymphocytes migrate from the bone marrow to the thymus, where they mature and differentiate until activated.
Thyroid
The thyroid is a large endocrine gland situated in the base of the neck; it regulates the metabolic rate.
Thyroid gland
The thyroid gland is a highly vascular organ located at the front of the neck, which secretes the hormone thyroxine directly into the blood, and is a part of the endocrine system of ductless glands.
Thyroid Stimulating Hormone (TSH)
Thyroid stimulating hormone (TSH) is a hormone produced by the anterior lobe of the hypophysis (pituitary gland), which stimulates the growth and function of the thyroid gland. It is measured as part of the diagnostic test to determine hypothyroidism. It is also known as thyrotropin.
Thyrotropin
Thyrotropin is a hormone secreted by the anterior pituitary; thyrotropin stimulates the thyroid gland. It is also called thyroid stimulating hormone (TSH). Thyrotropin is used as a diagnostic test to differentiate between primary and secondary hypothyroidism.
Thyrotropin Releasing Factor (TRF)
Thyrotropin Releasing Factor (also known as TRH or Thyrotropin Releasing Hormone) is a hormone secreted by nerve endings in the hypothalamus and then transported to the anterior pituitary. TRH directly affects the anterior pituitary gland cells by increasing their output of thyroid-stimulating hormone, TSH, which has many important affects throughout the body -- one of which is control of metabolism.
Thyrotropin Releasing Hormone (TRH)
Thyrotropin Releasing Hormone (also known as TRF or Thyrotropin Releasing Factor) is a hormone secreted by nerve endings in the hypothalamus and then transported to the anterior pituitary. TRH directly affects the anterior pituitary gland cells by increasing their output of thyroid-stimulating hormone, TSH, which has many important affects throughout the body -- one of which is control of metabolism.
Thyroxine (T4)
Thyroxine, also referred to as T4, is one of the hormones synthesized and secreted by the thyroid gland; it acts to increase the rates of chemical reactions in almost all cells of the body, thus increasing the general level of body metabolism. Thyroxine can be administered by mouth to treat underactivity of the thyroid gland.
Tibia
The tibia is the shin bone, i.e., the inner and larger bone of the lower leg.
Tibialis anterior
The tibialis anterior is one of the two muscles in the leg that extend from the tibia, or shin bone, to the bones of the foot; this muscle turns the foot inward and flexes the toes backward.
Tibiofibular junction
The tibiofibular junction is the junction between the tibia and fibula (bones of the lower leg).
Tidal volume
The tidal volume is the volume of air inspired or expired with each normal breath; normally about 500 ml.
Tilt table
A tilt table is a medical examination table used to test othostatic intolerance by tilting a person head-up or head-down from the horizontal position. The table typically has a footboard and straps or handles to prevent the patient or subject from sliding off during examination.
Tilt table test
A tilt table test is a procedure used to determine if decreased blood flow to the head will initiate orthostatic intolerance, a condition associated with fainting. At the beginning of the test, the subject is asked to lie supine on a table. The table is then angled upward from the horizontal so that the subject is inclined to a near vertical position. During the test, symptoms are continuously monitored as well as electrocardiogram (ECG or EKG), heart rate and blood pressure.
Time Cot
Time Constraint for loading
Time cue
Time cues, which are present in everyday life, make it possible for plants and animals to recognize and respond to their environment. Examples of time cues include time of day, season of year, phase of the moon, etc.
Time-integrated
Time-integrated means summed or accumulated over a period of time.
TIMS
Thermal Infrared Mapping Spectrometer
Tinactin
Tinactin is the trademark name for the antifungal medication tolnaftate, which is prescribed in the treatment of superficial fungal infections of the skin.
TIR
Technical Information Release
Titer
Titer is the concentration of a substance or the strength of such a substance.
TLM
Telemetry
TLV
Threshold Limit Value
TM
Technical Monitor
TM
Telemetry
TM
Test Monitor
TMA
Test Monitoring Area
Tmax
Temperature Maximum
Tmin
Temperature Minimum
TMIS
Technical and Management Information System
TMR
Technical Monitor Representative
TMS
Teleoperator Maneuvering System
TO
Task Order
TOD
Greenwich True-To-Date Cartesian Coordinate
TOM
Test and Operations Manager
Torque
Torque is the turning effect produced when force is applied to a rotational axis.
Torque Velocity Dynamometer (TVD)
The Torque Velocity Dynamometer (TVD) measures torque, which is the turning effect produced when force is applied to a rotational axis. The contracting muscles associated with elbow and ankle joints apply force against a lever which measures the torque produced.
Torsional eye movements
Torsional eye movements are produced when the head rotates in the roll axis and are visual as a rotation of the eyeball with a sudden "jump" back in its original position.
TOT
Test Operations Team
Total body water (TBW)
Total body water (TBW) is all the water in the body, including water inside and outside the cells, including water in the gastrointestinal and urinary tracts.
Total energy expenditure (TEE)
Total energy expenditure (TEE) is the sum of energy expended to maintain basal metabolism and energy expended to perform physical activities. It can be determined accurately by using the doubly-labeled water method to measure carbon dioxide production.
Total hardness
Hardness is a common quality of water. Total hardness is a measure of the total amounts of divalent metallic cations (principally calcium and magnesium) in the water, expressed in terms of calcium carbonate equivalent. Calcium hardness and magnesium hardness are components of total hardness.
Total Lung Capacity (TLC)
Total lung capacity (TLC) is the maximum volume to which the lungs can be expanded with the greatest possible inspiratory effort; it is equal to the vital capacity (VC) plus the residual volume (RV) and is approximately 5800 ml.
Total peripheral resistance (TPR)
Total peripheral resistance is the resistance to blood flow in the whole systemic vascular bed. It is the difference between the mean arterial pressure and the central venous pressure, divided by the cardiac output (blood flow).
Total peripheral resistance index (TPRI)
Total peripheral resistance index (TPRI) is the resistance to blood flow in the whole systemic vascular bed, with body size taken into account.
Total sleep time
Total sleep time is equal to the total rest-period time minus total time spent awake.
Touchscreen
A touchscreen is a device used for interacting with a computer. Instead of pressing a button on a mouse or trackball, the user touches the screen on a laptop computer or the monitor connected to a desktop computer.
Toulene diisocyanate
Toulene diisocyanate is an industrial aromatic compound used in the manufacturing of polyurethane elastomers; it is a toxic substance that is an irritant to the lungs, skin and eyes.
Toxic
Toxic means harmful, destructive or deadly.
Toxicological
Toxicological refers to the study of poisons and the treatment of poisoning.
Toxicology
Toxicology is the study of harmful substances called toxicants and their effect on organisms. More specifically, toxicologists study the molecular structure of toxicants; exposure of humans and animals to toxicants; absorption, distribution and bioprocessing of toxicants in the body; and pathologic conditions caused by toxicants.
Toxigenic
Toxigenic means to have the ability to produce toxin.
Toxin
A toxin is a poisonous substance. It can be a specific product of the metabolic activities of a living organism. Toxins in the body are typically capable of inducing antibody formation.
TP
Training Plan
TPS
Test Procedure Sheet
TPS
Thick Plastic Stack
TRA
Training Requirement Analysis
Tracer
A tracer is a substance that can be readily identified, such as an isotope, used to trace the course of a chemical or biological process or determine the size of a space that cannot be directly measured.
Trajectory
A trajectory is the path traced by any body moving as a result of an externally applied force, considered in three dimensions. Trajectory is sometimes used to mean flight path or orbit, but orbit usually means a closed (e.g., circular or elliptical) path and trajectory, a path that is not closed.
Transcranial doppler
A transcranial doppler is an ultrasonic scan performed to provide information about the presence, quality and dynamics of blood circulation in the brain. It measures the rate of blood flow through cerebral arteries. Narrowed blood vessels produce high flow rates, indicating possible narrowing or a spasm of a blood vessel; high rates may also indicate an arteriovenous malformation.
Transducer
A transducer is a device that receives energy from one system and transmits it, often in a different form, to another.
Transduction
Transduction is the transfer of energy from one system to another; often the energy is received by one system which retransmits it to another is a different form. Transduction can also refer to a method of genetic recombination by which DNA is transferred from one cell to another by a virus.
Transearth coast
Transearth coast denotes travel from the moon to earth.
Transfer function
A transfer function is a mathematical expression of the relationship between the input signal and output signal of a system.
Transferrin
Transferrin is a protein that transports iron in the blood.
Transient
Transient means to stay only a short time.
Translation
Translation is movement of a body from one location to another.
Translocation
Translocation (in genetics) is the transfer of part of a chromosome to a different position on a nonhomologous chromosome as a result of abnormal breakage and refusion.
Translunar coast
Translunar coast denotes travel from the earth to the moon.
Transmitter
A transmitter is a chemical which a neuron uses to influence the activity of an anatomically adjacent cell body, such as a hair cell. A neurotransmitter is any one of numerous chemicals that modify or result in the transmission of nerve impulses between synapses. A transmitter can also refer to electronic equipment that generates and amplifies a carrier wave, modulates it with a meaningful signal, as derived from speech or other sources, and radiates the resulting signal from an antenna.
Transpiration
Transpiration is the act or process of giving off vapor containing waste product through the stomata of plant tissue or pores of the skin.
Transport adenosine triphosphatase (Transport ATPa
Transport ATPase is an enzyme that catalyzes the release of the terminal phosphate group of adenosine 5'-triphosphate. The release of this phosphate group facilitates the transfer of certain ions (i.e., sodium, potassium, calcium, magnesium, etc.) through a biological membrane against a concentration gradient.
Transport ATP
ATP is the abbreviation for adenosine 5’-triphosphate. One function of ATP is the active transport of ions and molecules across cell membranes. Transport ATP has specific affinities for only one or two substrates, meaning it can only transport a few specific molecules or ions across cell membranes.
TRAP
Tartrate-resistant acid phosphatase
TRB
Test Review Board
Treadmill
A treadmill is a device operated by walking on the moving steps of a wheel or treading an endless sloping belt.
TRF
Thyrotropin Releasing Factor
TRG
Training
Triaxial
Triaxial means having or pertaining to three axes.
Triceps
The triceps is a muscle with three heads of origin, particularly the triceps brachii, which is situated on the back of the upper arm and contracts to extend the forearm.
Triceps surea
The triceps surea is the "three-headed" calf muscle, composed of the one-headed soleus and the two-headed gastrocnemius muscles.
Trichosporon
Trichosporon is a genus of imperfect fungi that possess branching septate hyphae with arthroconidia and blastoconidia. These organisms are part of the normal flora of the intestinal tract of humans.
Triglyceride
Triglyceride is a compound consisting of a fatty acid (oleic, palmitric, or stearic) and glycerol. Triglycerides make up most animal and vegetable fats and are the principle lipids in the blood, where they circulate, bound to a protein, forming high- and low-density lipoproteins. The total amount of triglycerides and the amount, proportions, and kind of lipoproteins are important in the diagnosis of treatment of many diseases and conditions, including diabetes, hypertension, and heart disease.
Triiodothyronine (T3)
Triiodothyronine (T3) is a hormone that helps regulate growth and development, helps control metabolism and body temperature, and, by a negative-feedback system, act to inhibit the secretion of thyrotropin by the pituitary.
Tritiated thymidine
Tritiated thymidine is thymidine (a nitrogen-containing base linked to the sugar D-2-deoxyribose) in which some of the hydrogen atoms have been replaced with tritium (hydrogen-3). It is used as a tracer for measuring DNA synthesis.
Tritium (3H)
Tritium is a radioactive isotope of hydrogen with a nucleus composed of three neutrons and one proton; it is commonly used as a chemical tracer because it emits low levels of radioactivity.
TRR
Thermal Radiator Rotation
TRS
Test Record Sheet
Trypanothione reductase
Trypanothione reductase is the key enzyme in the transmission of Chagas disease, a blood disease caused by the protozoan genus Trypanosoma.
Trypsin
Trypsin is an enzyme secreted by the pancreas that continues the digestion of proteins by breaking down peptones into smaller peptide chains.
Trypsin inhibitor
Trypsin inhibitor is a protease inhibitor, stopping the protein breakdown that trypsin produces.
Trypsinogen
Trypsinogen is the inactive form of trypsin, an enzyme secreted by the pancreas that continues the digestion of proteins by breaking down peptones into smaller peptide chains. Trypsinognen is converted to trypsin in the duodenum by the action of the enzyme enteropeptidase.
Trypticase soy agar (TSA)
Trypticase soy agar (TSA) is a blood agar base that can be used for the isolation and maintenance of all organisms except those with special nutritional requirements. It contains an inhibitor that keeps fungi from growing on the sample.
Trypticase soy broth
Trypticase soy broth is a general purpose nutrient culture medium, which contains substrates for microbial growth such as pancreatic digest of casein, papaic digest of soybean meal, sodium chloride and water. Trypticase soy broth supports the growth of most organisms and can be used to generate mass quantities for biochemical tests; it can also be used to observe colony morphology, develop pure cultures, and determine bacterial quantities.
TSP
Twisted Shielded Pairs
TTL
Transistor to Transistor Logic
TTY
Teletypewriter
Tuberculin skin test
The Tuberculin skin test is used to determine past or present tuberculosis infection based on a positive skin reaction, using one of several methods. A purified protein derivative (PPD) if tubercle bacilli, called tuberculin, is introduced into the skin by scratch, puncture, or injection. If a raised, red or hard zone forms surrounding the tuberculin test site, the test is read as positive. However, a negative tuberculin reaction does not rule out a diagnosis of previous or active tuberculosis.
Tuberculosis (TB)
Tuberculosis (TB) is an infectious disease caused by a bacteria, Myobacterium tuberculosis which may affect almost any tissue or organ of the body. The most common target of the disease, however, is the lungs.
Tungsten
Tungsten is a gray-white heavy high-melting ductile hard polyvalent metallic element that resembles chromium and molybdenum in many of its properties and is used especially for electrical purposes and hardening alloys (as steel).
Turbid
Turbid means not clear.
Turbidity
Turbidity means having sediment or foreign particles stirred up or suspended, usually within a liquid.
TW
Twisted
TWDS
Twisted Double Shielded
TWL
Total Weight Loss
TWS
Twisted Shielded
TWX
Teletype Wire Transmission
Tympanic membrane
The tympanic membrane, or eardrum, is a thin semitransparent membrane that stretches across the ear canal and separates the outer and middle ear.
Typhoid
Typhoid means pertaining to or resembling typhus. Typhus is any of a group of acute infectious diseases caused by various species of Rickettsia and usually transmitted from infected rodents to humans by the bites of lice, fleas, mites, or ticks. These diseases are all characterized by headache, chills, fever, malaise, and a maculopapular rash.
Tyrosine
Tyrosine is a white crystalline amino acid derived from the hydrolysis of protein, used as a growth factor in nutrition and as a dietary supplement.
U
Underfloor
U-C
Unit Cost
U.S.
United States
UCD
Urine Collection Device
UCR
University of California at Riverside
UCS
User Clock Signal
UCSU
User Clock Signal Update
UDS
Universal Documentation System
UEB
Upper Electronic Box
UGSE
User-Supplied Ground Support Equipment
UHF
Ultrahigh Frequency
Ulcer
An ulcer is a break in the skin or in the mucous membrane lining the alimentary tract that fails to heal and is often accompanied by inflammation.
Ulna
The ulna is the inner and longer bone of the forearm.
ULT
Ultimate (Loads)
Ultrasound
Ultrasound is the use of sound with a frequency higher than 20,000 Hertz to obtain images for medical diagnostic purposes.
Ultrastructure
Ultrastructure is the arrangement of the smallest elements making up a body, or the arrangement of ultramicrons making up a substance.
Ultraviolet (UV)
Ultraviolet light is the part of the electromagnetic spectrum that has wavelengths shorter than visible light but longer than X-rays; it lies outside the visible spectrum at its violet end. Ultraviolet light (radiation) is harmful to humans.
Ultraviolet (UV) radiation
Ultraviolet (UV) radiation results from wavelengths of energy from just beyond the violet in the visible spectrum to the border of the X-ray region. Exposure to types of UV radiation can cause damage to the body, namely the skin. The layer of ozone in the earth's stratosphere normally forms a protective shield, blocking the majority of the sun's harmful UV rays from reaching the ground.
UM
Microcomputer
Umbilical
An umbilical is any of various external electrical lines or fluid tubes which connects one portion of a system to another.
The Unified Tri-Service Cognitive Performance Assessment Battery (UTC-PAB) represents the primary metric for a Level II evaluation of cognitive performance in the JWGD3 MILPERF chemical defense biomedical drug screening program. Emphasis for UTC-PAB development has been on the standardization of test batteries across participating laboratories with respect to content,computer-based administration, test scoring, and data formatting. This effort has produced a 25-test UTC-PAB that represents the consolidation and unification of independent developments by the Tri-Service membership. Test selection was based upon established test validity and relevance of military performance. Sensitivity to effects of hostile environments and sustainedoperations were also considerations involved in test selection. Information processing, decision making, perception, and mental workload capacity are among the processes and abilities addressed in the battery. The UTC-PAB represents a dynamic approach to battery development. The nature of the biomedical drugs screened and information from performance centered task analyses will direct the form of future versions of the battery.
UNO
Unless Noted Otherwise
Upper respiratory infection
An upper respiratory infection is any infectious disease of the upper respiratory tract. These infections include the common cold, laryngitis, pharyngitis, rhinitis, sinusitis, and tonsillitis.
Urea
Urea is a nitrogen-containing substance normally cleared from the blood by the kidney; it is the chief solid component of mammalian urine and an end product of protein decomposition. Diseases that compromise kidney function often lead to increased blood levels of urea, which are measured by the blood urea nitrogen (BUN) test.
Urethritis
Urethritis is the inflammation of the urethra (the canal through which urine is discharged in most mammals).
Uric acid
Uric acid is the end product of purine (a nitrogen-containing component of nucleic acids and some other biochemicals) breakdown in primates; it is the major form in which nitrogen from metabolized substances is excreted from the body.
Urinalysis
A urinalysis is the chemical analysis of urine.
Urine Monitoring System (UMS)
The Urine Monitoring System (UMS) space flight hardware supports metabolic experiments by preparing urine samples for return to ground for analysis after flight. It automatically collects, measures, and samples individual urine samples in either a microgravity or normal gravity environment and accommodates both male and female users.
Urine specific gravity
Urine specific gravity is a measure of the degree of concentration of a sample of urine, and usually indicates fluid intake. The higher the specific gravity, the less the fluid intake.
Urokinase
Urokinase is a proteinase found in mammalian urine, which cleaves plasminogen to plasmin. Urokinase is used to treat people suffering from blood-clot conditions.
US
United States
USA
United States of America
USR
User Support Room
USSR
Union of Soviet Socialist Republics
UT
Universal Time
UTC
Universal Time Correlated
UTC
User Time Clock
UTCU
User Time Clock Update
Utricle
The utricle is the larger of the two membranous sacs within the vestibule of the ear; it forms part of the membranous labyrinth.
Utricular
Utricular refers to the utricle, the larger of the two membranous sacs within the vestibule of the ear, which forms part of the membranous labyrinth.
V
Volts
V(C)
Blood volume in the pulmonary alveolar capillaries.
V-I
Video or Instrumentation
VAB
Vehicle Assembly Building
VAC
Volts Alternating Current
VAFB
Vandenberg Air Force Base
Vagal
Vagal means pertaining to or brought about by the vagus nerves.
Vagus nerve
The pair of vagus nerves are the 10th cranial nerves (originating in the brainstem) and are essential for the sensibilities and functions of many parts of the body. They contain sensory, motor, and parasympathetic nerve fibers. Parts of the vagus nerves participate in control of speech, swallowing, blood pressure, heartbeat, and other important body functions.
Valsalva maneuver
The Valsalva maneuver is an attempt to forcibly exhale with the nose and mouth closed.
Van
Van refers to the enzymes found in bacteria that is resistant to the antibiotic Vancomycin.
Van Allen radiation belts
The Van Allen radiation belts are two doughnut-shaped regions of trapped radiation around the Earth. The belts, which do not extend over the north and south poles, consist mainly of high-energy protons and electrons that exist at varying altitudes between 320 and 32,400 kilometers above the Earth. The charged particles bounce and drift in a spiral motion around the Earth’s magnetic lines of force at speeds of several kilometers per
Vapor diffusion crystallization
Vapor diffusion crystallization is a technique used for protein crystal growth by mixing a protein solution and precipitating solution into a single liquid drop. As water leaves the liquid drop through vaporization, the protein solution becomes more concentrated causing the protein to crystallize.
Variable gravity
Variable gravity refers to conditions of different levels of gravity. Gravity is the force with which two bodies having mass are attracted to each other. The reference used to measure gravity forces is the standard sea-level Earth gravity which is called One-G (1-G). Certain devices, like centrifuges, can simulate variable gravity levels.
VAS
Vertical Access Simulator
Vascular
Vascular means of or pertaining to the blood vessels.
Vascular conductance
Vascular conductance is the ratio of blood flow through a blood vessel. The blood flow per unit of pressure difference is measured.
Vascularity
Vascularity is the state of having blood vessels, especially a plentiful supply of them.
Vascularization
Vascularization refers to the presence of blood vessels in biological tissues.
Vasculature
Vasculature is the vascular network of an organ or the distribution of blood vessels in an organ or tissue.
Vasoactive
Vasoactive indicates the tendency to cause vasodilation or vasoconstriction.
Vasoconstrict
Vasoconstrict means narrowing of the blood vessels.
Vasoconstrictive
Vasoconstrictive means able to cause a constriction of blood vessels.
Vasodepressor
Vasodepressor means the reduction of tone in blood vessels with vasodilation and resulting lowered blood pressure.
Vasodilation
Vasodilation means dilation of the blood vessels.
Vasomotor
Vasomotor pertains to the nerves and muscles that control the constriction or dilation of blood vessels.
Vasopressin
Vasopressin (also called antidiuretic hormone, ADH) is a hormone produced and released in the posterior pituitary gland which causes the kidneys to retain water, thus increasing the water content of the body. In high concentrations, it causes the constriction of blood vessels throughout the body and consequent elevation of blood pressure.
Vasopressor
Vasopressor means producing constriction of the capillaries and arteries (vasoconstriction) and a rise in blood pressure, usually understood to be systemic arterial pressure unless otherwise specified. A vasopressor is also an agent that produces vasoconstriction.
Vasovagal
Vasovagal relates to the action of impulses in the vagus nerve on the circulation. The vagus reduces the rate at which the heart beats, and thus lowers its output.
Vastus
Vastus literally means "great muscle."
Vastus intermedialis
The vastus intermedialis is one of the three muscles that form part of the quadriceps muscle of the thigh, located at the front of the thigh.
VAX
Digital Equipment Corporation Computer, Variable Access Exchange
VCG
Vapor Crystal Growth
VCM
Volatile Condensable Materials
VCO2 max
VCO2 max indicates maximum carbon dioxide production.
VCS
Voltage Carrier Signal
VDC
Volts Direct Current
VDE
Video Data Encoder
VDU
Visual Display Unit
Vection
Vection is the sensation of self-rotation in the opposite direction of a provided (rotating) stimulus.
Vectorcardiogram (VCG)
A vectorcardiogram (VCG) is a tracing of the direction and magnitude of the electrical forces of a heart's activity during the cardiac cycle. It is produced by the simultaneous recording of the heart from three standard leads using an oscilloscope.
Vectorcardiograph
A vectorcardiograph is a modified electrocardiograph (EKG) that uses the signals collected from the leads to present the data as three-dimensional vector loops.
Vectorcardiography
Vectorcardiography is a form of electrocardiography in which the electrodes are placed on the body in specific positions to determine the direction of the heart's action currents.
VEE capsid protein
VEE capsid protein is the one domain of a proteinase required for the replication of Venezuelan Equine Encephalitis Virus. It is a target for antiviral drugs.
Vegetative
Vegetative means non-reproductive or relating to the nonsexual organs of a plant, such as root, stem and leaves.
Velocity
Velocity is the rate of movement, or more specifically, the distance traveled per unit of time.
Velocity storage
Velocity storage is the indirect pathway responsible for the slower changes in optokinetic nystagmus and opkinetic after-nystagmus eye movements. It gets it name because it stores activity related to slow phase eye velocity.
Venomotor
Venomotor means causing change in the diameter of the inside of a vein.
Venomotor reflex
The venomotor reflex causes a change in the diameter of the inside of a vein.
Venous
Venous means relating to the blood vessels which carry blood to the heart (veins). All veins, except the pulmonary vein, carry non-oxygenated blood.
Venous compliance
Venous compliance is the change in blood volume for a given change in pressure produced by a cuff around the arms or legs. The cuff pressure restricts blood flow from the tissues and causes the blood to pool.
Venous pressure
Venous pressure is the blood pressure in the veins of the body.
Ventilation
Ventilation is the passage of air into and out of the respiratory tract.
Ventilation Exchange (VE)
Ventilation Exchange (VE) is the exchange of gases, primarily oxygen and carbon dioxide, during the passage of air into and out of the respiratory passages.
Ventilation-perfusion ratio
The ventilation-perfusion ratio is the relationship between lung ventilation and pulmonary blood flow in the lung tissue.
Ventral
Ventral means relating to, situated at, or close to the front of the body or to the anterior part of an organ.
Ventricular
Ventricular means relating to a ventricle, which is the name of certain cavities of the heart and brain.
VERIF
Verification
Vertebral bodies
Vertebral bodies support most of the axial load of the normal spine and consist of the thoracic and lumbar vertebrae.
Vertebrates
Vertebrates are organisms that have a spinal column or backbone, including fish, amphibians, reptiles, birds and mammals.
Vertex
Vertex is the highest point of something; apex. The crown or top of the head.
Vertigo
Vertigo is a disabling sensation in which the affected individual feels that either he, himself or his surroundings are in a state of constant movement. It is most often a spinning sensation, but there may be a feeling that the ground is tilting.
Vestibular
Vestibular means of or relating to the vestibule of the ear, a cavity situated at the entrance to the bony labrinth (a part of the inner ear) containing the organs that provide the sense of balance.
Vestibular apparatus
The vestibular apparatus, also called the vestibular system or organ, helps to maintain the body's equilibrium and is located at the entrance to the bony labyrinth of the inner ear. The vestibular apparatus consists of the utricle, the saccule and three membranous semicircular canals.
Vestibular sled
The vestibular sled was a device flown on Spacelab missions that was designed to test the functional organization of the human vestibular apparatus and orientation system, as well as the vestibular adaptation processes to microgravity. The sled used during the D-1 mission was configured with a seat for the test person which could be moved backwards and forward on mounted rails with precisely adjusted accelerations.
Vestibular system
The vestibular system consists of three membranous semi-circular canals, the saccule and the utricle, all of which work together to govern equilibrium and balance. The system is located at the entrance to the bony labyrinth of the inner ear.
Vestibulo-ocular reflex (VOR)
The vestibulo-ocular reflex (VOR) is the reflex movement of the eyes in the direction opposite to that in which the head is moved; it allows you to maintain a fixed gaze on an object while your head is moving. Nerve signals that cause the reflex originate in the vestibular organs of the inner ear.
Vestibulocochlear cranial nerve
The vestibulocochlear cranial nerve is one of the 12 pairs of nerves that arise directly from the brain and leave the skull through separate apertures. Also called the eighth cranial nerve, the vestibulocochlear cranial nerve is responsible for carrying sensory impulses from the inner ear to the brain. It thus has two branches, the vestibular nerve and the cochlear nerve. The cochlear nerve carries impulses from the ear and is therefore the nerve of hearing, while the vestibular nerve serves equilibrium, carrying impulses from the semicircular canals, utricles, and saccules with information about posture, movement and balance.
VFI
Verification Flight Instrumentation
VFSC
Valley Forge Space Center
VFT
Verification Flight Test
VHF
Very High Frequency
VHM
Voluntary Head Movements
VHSIC
Very High Speed Integrated Circuit
Viability
Viability refers to the capability of living.
Viable
Viable means capable of developing, growing and sustaining life.
Vibration
Vibration is a rapid back and forth motion of a particle or solid.
Vibrocardiogram
A vibrocardiogram is a tracing of the vibrations of the heart sounds made by an apparatus consisting of a microphone actuating a cathode ray.
VIP
Very Important Person
VIR
Visible Infrared Radar
Viral gastroenteritis
Viral gastroenteritis is an inflammation of the intestine caused by a virus. The symptoms usually include abdominal cramps, diarrhea, nausea, and vomitting.
Virology
Virology is the study of viruses and viral diseases.
Virulence
Virulence is the disease-evoking power of a microorganism in a given host.
Virus
A virus is any member of a large group of submicroscopic infective agents, regarded either as extremely simple microorganisms or as extremely complex molecules, that typically contain a protein coat surrounding an RNA or DNA core of genetic material but no semipermeable membrane, that are capable of growth and multiplication only in living cells, and that cause various important diseases in humans, lower animals, or plants. Viruses replicate by releasing their DNA or RNA into the host cell; the viral DNA or RNA in turn directs the host cell's "machinery" to churn out more viral DNA or RNA. Classification of viruses depends on mode of transmission, host range, symptoms and other factors.
VIS/UV
Visual/Ultraviolet
Visceral
Visceral means of, or pertaining to, or affecting the viscera. Viscera is a term used to refer to the organs in the cavities of the body, especially those in the abdominal cavity. Examples include organs of the digestive, respiratory, urogenital, and endocrine systems as well as the spleen, the heart, and great blood vessels.
Visual
Visual refers to the sense of vision, the sense that enables perception of objects in the environment by means of the eyes.
Visual acuity
Visual acuity is a measure of the sharpness of vision.
Visual cortex
The visual cortex is the part of the brain that detects the forms of objects, brightness of the individual parts of the objects, shading, and spatial organization of the visual scene.
Visual field
The visual field is the area simultaneously visible to one eye without movement; often measured by means of an arc (perimeter) located 330 mm from the eye.
Visual phosphenes
Visual phosphenes are best described as subjective sensations of flashes of light; they are thought to result from radiation damage to the brain or eye.
Visual surround
Visual surround is the entire scene visible to a subject or patient while an experiment or test is taking place. It is usually produced by artificial means and may contain images or drawings.
Visuo-motor
Visuo-motor means both visual and motor, i.e., a nerve with both functions.
Visuo-motor coordination
Visuo-motor coordination is the ability to synchronize visual information with physical movement.
Vital Capacity (VC)
Vital capacity (VC) is the maximum amount of air that a person can expel from the lungs after first filling the lungs to their maximum extent; it is equivalent to the inspiratory reserve volume (IRV) plus the tidal volume (TV) plus the expiratory reserve volume (ERV). (VC = IRV + TV + ERV)
Vitamin
A vitamin is an organic molecule needed in trace amounts for normal growth and metabolic processes.
Vitamin A
Vitamin A is a fat-soluble solid terpene alcohol essential for skeletal growth, maintenance of normal mucosal epithelium and visual acuity.
Vitamin B
The B complex vitamins are B1 (thiamine), B2 (riboflavin), B6 (pyridoxine), B12 (cyanocobalamin), and B17 (Laetrile). Thiamine is a water-soluble crystalline compound essential for normal metabolism and for the health of the cardiovascular and nervous systems; it plays a key role in the metabolic breakdown of glucose to yield energy in body tissues. Riboflavin functions as a coenzyme in the oxidative processes of carbohydrates, fats, and proteins; it is also important in the prevention of some visual disorders, especially cataracts. Pyridoxine functions as a coenzyme essential for the synthesis and breakdown of amino acids, the conversion of tryptophan to niacin, the breakdown of glycogen to glucose-1-phosphate, the production of antibodies, the formation of heme in hemoglobin, the formation of hormones important in brain function, the proper absorption of vitamin B12, the production of hydrochloric acid and magnesium, and the maintenance of sodium and potassium balance, which regulate body fluids and functioning of the nervous and musculoskeletal systems.
Vitamin C
Vitamin C is a fat-soluble white crystalline vitamin essential for the formation of collagen and fibrous tissue for normal intercellular matrices in teeth, bone, cartilage, connective tissue, and skin, and for the structural integrity of capillary walls. Vitamin C also aids in fighting bacterial infections and interacts with other nutrients.
Vitamin D
Vitamin D is a fat-soluble vitamin that enhances the absorption of calcium and phosphorus from the intestine and promotes their deposition onto the bone.
Vitamin D metabolite
Vitamin D metabolites are slight variations of the vitamin D hormone which are formed by the addition of hydroxyl groups (OH) when vitamin D is metabolized in the liver and kidney. Metabolites of vitamin D are the biologically active forms of the molecule.
Vitamin D2
A white crystalline compound produced by ultraviolet irradiation of ergosterol. Vitamin D2, also called calciferol and ergocalciferol, has the chemical symbol C28H44O.
Vitamin E
Vitamin E is a fat-soluble vitamin essential for normal reproduction, muscle development, resistance of erythrocytes to hemolysis, and various other biochemical functions. It is an intracellular antioxidant that maintains the stability of polyunsaturated fatty acids and other fat-like substances, including vitamin A and hormones of the pituitary, adrenal and sex glands.
Viton
Viton is a high performance synthetic rubber (developed by Du Pont in the early 1950s) that has exceptional resistance to oils and chemicals at elevated temperatures.
VITR
Video Instrument Tape Recorder
VLBI
Very Long Baseline Interferometry
VLSID
Very Large Scale Integrated Device
Void
Void means to empty or evacuate waste from the body. For instance, throughout the day, the human being excretes urine several times; each of these is called a void. The composition of urine changes in a cycle every 24 hours. The first void in the morning contains many minerals, electrolytes and metabolism-end products. During the day, the amount of dissolved substances is reduced.
VOL
Volume
Volatile
Volatile means evaporating readily at normal temperatures and pressures, i.e., capable of being readily vaporized.
Volitional
Volitional means voluntary, or done by an act of will.
Volume of inspired oxygen (VO2 Max)
The volume of inspired oxygen is the maximum oxygen uptake per minute by the lungs, and is usually referred to as VO2 Max.
Volume-regulatory mechanisms
Volume-regulatory mechanisms is a term that refers to all mechanisms that result in an increase or reduction of body fluids, mainly intracellular fluids such as blood plasma.
Voluntary
Voluntary means relating or acting in obedience to the will; not obligatory.
VOM
Volt - Ohm Meter
Vortex
Vortex means fluid flow involving rotation about an axis.
Watershed hydrology refers to the distribution and circulation of water on land, in soil and rock, and in the atmosphere.
Wavelength
A wavelength is the distance between two successive points at which the wave has the same phase. For example, visible light has a wavelength of between 400 nm (violet) to 750 nm (red).
WBC
White Blood Cell
WBS
Work Breakdown Structure
WETF
Weightless Environment Training Facility
White blood cell
White blood cells are the body's primary defense against invading organisms and other foreign material. These cells use two main methods of defense: phagocytosis (consumption of the invader) and the immune response (see antibodies).
White noise
White noise is sound containing all frequencies audible to humans, at equal intensity. It is often used to mask other sounds that may distract people. White noise is analogous to white light, which contains all frequencies (colors) of light.
WIF
Water Immersion Facility
WISP
Waves in Space Plasma
Witt-Cameron standard
A Witt-Cameron standard consists of three chambers containing dipotassium hydrogen phosphate to simulate bone attenuation (density). It is used to standardize bone scans from different scanning devices.
WMM
Water Microbiological Monitor experiment
WMS
Waste Management System
WMT
Waste Management Tray
WP
Work Package
WPO
Western Programs Office
WPS
Word Processing System
WQM
Water Quality Monitor experiment
WR
Weather Radar
Wright’s stain
Wright’s stain is a dry stain mixture of eosinates of polychromed methylene blue used in staining of blood smears.
WRT
With Respect To
WSTF
White Sands Test Facility
WTR
Western Test Range
WUC
Work Unit Code
X
Top assembly stowed configuration
X-ray
X-ray is a procedure used to exam, treat, or photograph with X-rays. X-rays are any of the electromagnetic radiations with extremely short wavelengths.
X-ray computed tomography
X-ray computed tomography is a technique that utilizes X-ray light to generate a image, via a computer, of the surface structure of a geological sample.
X-ray diffraction
X-ray diffraction is a method for studying microscopic crystal form and structure.
X-ray fluorescence
X-ray fluorescence is a method of determining the chemical composition of a material. When a chemical element absorbs X-rays of short wavelength, it emits X-rays of a longer wavelength that is characteristic of the element. For analysis, the material is scanned with short-wavelength X-rays and the emitted light is analyzed to determine which elements it contains.
XFER
Transfer
XGP
Experimental Geosynchronous Platform
XTE
X-Ray Timing Explorer
XX
Top assembly fixed item (rack mounted)
Xylem
Xylem is a woody plant tissue that is vascular in function, enabling transport of water with dissolved minerals within the plant, usually upward.
Xylose
Xylose is a type of sugar derived from the xylans in plant cell walls; it is used to evaluate intestinal function.
Yaw
Yaw is horizontal (side-to-side) movement about a vertical axis, such as the forehead-to-chin axis of the head.
Yeast
A yeast is a unicellular fungus that belongs to the phylum fungi,family Saccharomycetaceae.
Yeast-malt broth
Yeast-malt broth is a medium used to induce sporulation and reduce vegetative growth in the cultivation of fungi.
Yellow fever
Yellow fever is an acute infectious disease of subtropical and tropical New World areas, caused by a filterable virus transmitted by a mosquito of the genus Aedes and characterized by jaundice and dark-colored vomit resulting from hemorrhages.
Zero gravity (zero-g, 0-G)
Zero gravity (zero-g, 0-G) means without the force of gravity present, as in space.
Zeta potential
Zeta potential is the electrostatic potential of a molecule or particle. It is usually measured by electrophoretic mobility and is related to the surface potential and a measure of the electrostatic forces of repulsion the particle or molecule is likely to meet when encountering another of the same sign of charge.
Zinc
Zinc is a n essential nutrient widely distributed in the body. It is a component of more than 100 enzymes, including those responsible for RNA and DNA synthesis. The tissues having the highest zinc content are the bones, liver, prostate and testes. Zinc is essential for healthy skin, wound healing and growth.
Zirconium oxide
Zirconium oxide is a chemical compound that has a high conductivity for oxygen ions. It is often used to make oxygen sensors because of this feature.
Zone-forming fungi
Streptomyces levoris, or the zone-forming fungi has naturally alternating vegetative mycelial and spore ring periodicity that can be easily observed by the naked eye. The zone-forming fungi are used to test if space flight factors have an effect on ring formation in fungi.