Valentin Petrovich GLUSHKO 
Founder of rocket engine design for the Soviet Union.  Bureau he founded (in 1929) went on to design first-stage engines including RD-107 and RD-108 (used on Sputnik) and other SS-6 boosters and the RD-253 first-stage of the Proton booster. 

Robert Hutchins GODDARD 
Considered the father of US rocketry.  Born in 1882.  A physics professor and experimental physicist.  Systematic, scientific, step-by-step advances was the method of his approach following his life goal of building a rocket that could travel to the moon. Goddard Published, in 1919, a report for the Smithsonian Institute: A Method of Reaching Extreme Altitudes, which postulated a solid-propellant moon rocket.  In 1923 he fired the first liquid-propellant rocket using liquid oxygen and benzene as fuels.  In 1930, in New Mexico, he launched a 10-ft long liquid-propellant rocket to 2,000 ft altitude and 500-mph; five years later to 7,250 ft altitude and to 550 mph with a tapered projectile body and gyro-stabilized exhaust fins.  His experimental groundwork helped make interplanetary travel possible. 

Alexei Mikhailovich ISAYEV 
Developed liquid propellant engines used on Soviet interplanetary craft and manned spacecraft; retro-rockets and maneuvering units for the Vostok, Voskhod, Soyuz, Polyot, Luna, Venera, Mars, Zond and Molniya-1 craft. 

Mstislav Vsevolodovich KELDYSH 
Academician and mathematician in aerodynamics and applied mathematics.  He and his colleagues performed many of the calculations relating to Soviet space missions. 

Sergi Pavolovich KOROLYOV 
Ukrainian rocket engineer.  Imprisoned by the Soviets from 1938 to 1944, after which he led the team designing advanced versions of the German V-2.  He developed the Soviets first ballistic missile.  He championed man-in-space.  He worked on Sputnik, Vostok, Voskhod and Soyuz as well as Molniya communications satellites.  His R-7 (SS-6) was used for many years as the primary vehicle for manned and unmanned missions.  Korolyov was plagued with ill-health as a result of his imprisonment and died at age 58 in 1966.  His remains are buried in the Kremlin Wall. 

Hermann OBERTH 
Submitted a doctoral thesis, By Rocket, to Interplanetary Space in 1923, which was rejected but later successfully published in the popular press despite its major mathematical bent.   Oberth went on to discuss multi-stage liquid-fueled rockets and "space station" satellites and then: The Way to Space Travel.  Drawn to build a rocket in connection with a movie, he designed a conical shape, liquid-oxygen and gasoline fuels, a "cone-jet" combustion chamber with vaporized injection. similar to but predating the V2.  Oberth worked only indirectly on the V-2 and was tapped ten years after WW-II to work on the US space satellite program. 

Mikhail Sergevich RYAZANSKIY 
Specialist in radio control systems for launch vehicles and for Vostok, Voskhod, Soyuz, Luna, Venera and Mars spacecraft. 

Yuri Pavlovich SEMENOV 
Manned flight project director.  Designer of Salyut-6 and Salyut-7, the MIR station complex. 

Konstantin Eduardovich TSIOLKOVSKI 
Born in 1857.  An early theoretician in flight and interplanetary travel and teacher of mathematics and physics.  Published The Exploration of Cosmic Space by Rocket, in 1898.  Although he had never seen a liquid propellant rocket fly... he produced a workable design for a liquid-cooled rocket engine combustion chamber. Although his ideals were originally ignored they soon revolutionized the use of the rocket as the key component in the exploration of space.  Likewise he is now regarded as one of the founder’s of modern space exploration.   

Jules VERNE 
Novelist, noted by many as their early inspiration and motivation for rocket and space research.  Particularly his 1865 From the Earth to the Moon in which three men traveled in a cannon ball around the moon to return to earth.  Early science fiction. 

Werner VON BRAUN 
Still in his 'teens he joined the German Ordinance Ballistics Section which was studying liquid-propellant rockets.  By age 33 von Braun was working with Walter DORNBERGER at Peenemunde on the A-4 rocket (renamed V-2), but also research on three stage space vehicles.  Following WW-II von Braun moved to the US space effort at White Sands, New Mexico and Huntsville, Alabama and has been singularly instrumental in development and promotion of US manned space projects.  

Mikhail Kuzmich YANGEL 
Developed Soviet silo-launched  military ICBMs and SS-18 as well as the small Cosmos and Intercosmos satellites. 

Heracleides, born about 388 BCE; died 315 BCE

Heracleides traveled to Athens as a young man and studied in Plato's Academy; he was thought of to done well because when Plato left on journeys, Heracleides was left in charge of the academy. He is known today for his suggestions in astronomy that were very important, even though at the time no one thought much his work. He had recognized heavenly objects, and especially for the fixed stars, took part in an even rotation about the earth from east to west; Heracleides was the first man to suggest the rotation of the earth.

Aristarchus, born 320 B.C; died 250 BCE

 Aristarchus came to Alexandria in his youth and is known to
have studied with Strato. He is known as the most original, and
from the modern view, the most successful of the Greek
astronomers. Aristarchus believed that all the planets revolved
around the sun; when the moon is half-illuminated, the earth,
moon, and sun must occupy the pieces of a right triangle. The
distance of the sun from the earth (the hypotenuse of the
triangle), to the distance of the moon from the earth (the short
leg of the triangle). This theory was correct but he had no
instruments capable of measuring angles accurately, therefore, he
never obtained proof  Aristarchus knew it was not logical that the sun
revolved around the earth; he thought that the smaller object
should revolve around the larger and he was right.
 
 

Eratosthenes, born 276 BCE; died 196 BCE
 
 

 Eratosthenes was not only an astronomer and a geographer, but also a historian. He attempted to set up a scientific chronology,
where all events were dated from the Trojan war. He was known
as: Beta, the second letter of the Greek alphabet, for in several
of the directions, in which he chose to exert his talents, he
proved the second best in the world. Eratosthenes is best known
for having determined the size of the earth, at about 240 BCE.
To do this he made the note of the fact that on the day of
summer solstice, the sun was directly overhead in Syene (in
southern  Egypt) at the same time that it was seven degrees from
the zenith in Alexandria. This difference could only be due to the
curves of the earth's surface between syene and Alexandria.
Knowing the actual north-south distance between Syene and
Alexandria. It was possible to calculate the diameter of the
earth, if you assumed earth was a sphere with equal curvature on
all parts of its surface. Eratosthenes carried through the
calculation, and obtained his results in Greek units of distance
(stadia). Eratosthenes calculated the earth at a little over
25,000 miles--which is almost correct. His suspicion was proven true,
but was not verified until the voyage of Magellan, eighteen
centuries later.
 
 

Hipparchus, born 190 BCE; died 120 BCE
 
 

 Hipparchus was the greatest of the Greek astronomers. He
carried on the work of Aristarchus, measuring the size and
distance of the sun and moon. Hipparchus is known as the founder of trigonometry. Hipparchus also developed a star map by finding various stars latitude and longitude. He also found a uniform shift from
west to east, he accounted for this by saying that the north
celestial pole moved in a slow circle in the sky, completing one
cycle every 26,700 years. This meant the equinox arrived a trifling
earlier each year, and the effect was called the "precession
of the equinoxes."

Hipparchus was also the first to divide the stars into classes,
dependant on their brightness. The twenty brightest stars are of "first magnitude". Then, in order of decreasing brightness, are second, third, fourth, and fifth magnitudes, those of the sixth magnitude are just visible to the naked eye. This system has been kept to the present day. Hipparchus' most
ambitious achievement however was to work out a new scheme of the
universe. He reduced the number of heavenly spheres within the
outermost starry celestial vault to seven, one for each of the
planets. The individual planet, however, was not actually part
of the sphere. It was the part of a smaller sphere and it was
the center of, and it was the center of that smaller sphere that
was on the main sphere. The planet moved in a circle as the
small sphere turned, and it also moved along in a larger circle,
as the center of the small sphere turned, itself part of the large
sphere. The large sphere was the "deferent," the small sphere
the "epicycle." By adjusting the speeds of the two spheres, by
piling epicycle upon larger epicycle, the actual motion of the
planets could be duplicated. Hipparchus also introduced
the eccentric theory: a planet didn't move about the earth's
center, but about a fictitious point in space that was near the
earth's center, and this fictitious point in turn revolved about
the earth's center. Hipparchus' scheme of the universe was
highly complicated, but it preserved the axioms of Plato and
Aristotle and that the earth was the unmoving center of the
universe and that the planets moved in combinations of circles.
 
 
 
 

Ptolemy, born about 75; died date unknown
 
 

 Ptolemy is not known for his own work but for taking others'
ideas and placing them into a great synthesis. He composed
mostly on the work of Hipparchus, but since none of Hipparchus'
writings are still around, the system of the universe is known
as the Ptolemaic system. In the Ptolemaic system the earth is at
the center of the universe and the necessary planets revolve
around it, these planets are the moon, Mercury, Venus, the sun,
Mars, Jupiter, and Saturn. The Ptolemaic system was accurate enough that you could even see the reasoning through naked eye
Observations. It was not until the time of Tycho Brahe, fourteen
Centuries, later that observations of the planets were made with
even better accuracy than Ptolemy's theory. Ptolemy also created a star
catalogue listing  forty-eight star constellations (still in
use today).
 
 
 
 

Copernicus born February 19, 1473; died May 24, 1543
 
 

 Copernicus realized that tables of planetary positions
could be calculated more easily if it was assumed that the sun
was the center of the universe (heliocentric view), and not the earth (geocentric view). Meaning that the earth was moving through space and around the sun. Copernicus then decided to set up a mathematical system on how planetary positions could be calculated on this new basis. The Copernican
system explained some of the puzzling motions of the planets rather easily. The orbits of Mercury and Venus, according to the new system, would never take those planets farther than a certain distance from the sun, as viewed from the earth since the orbits of Mercury and Venus lay closer to the sun than does the orbit of the earth. Another explanation is that since the
earth would be travelling in a smaller orbit than Mars, Jupiter,
and Saturn it would periodically overtake those planets and
cause them to seem as if they were moving backwards in the sky.
Copernicus is responsible for the setting off the scientific revolution, which
was to overthrow many outdated aspects of Greek science, setting man on a new and more fruitful path.
 
 

Tycho Brahe born December 14, 1546; died October 24, 1601
 
 

 Tycho burst onto the scene of astronomy when he found a new star
which grew to be brighter than Venus for a year and a half before fading away. Tycho, in observing the new star, wrote a 52-page book on his observations, which described the star and its astrological significance. Tycho's book did three things: it established the
name: supernova for all exploding stars, it gave him his reputation as an
astronomer, and since Tycho showed, by parallax measurements,
that the heavens were not perfect and unchanging (something that
Aristotle had earlier proclaimed). Tycho built and worked in the first 
astronomical observatory in history. The Tychonic theory which
was a compromise of all astronomers ideas, suggested that all
planets except the earth revolved around the sun, then he said
the sun, with it's train of attendant planets, revolved
around the earth. Tycho corrected almost every important
astronomical measurement for the better, he also determined the
length of the year, to less than a second. He also estimated the
distance of Saturn the farthest planet at 45 million miles, only one-eighteenth off of the actual figure.
 
 
 
 

Galileo born February 15,1564; died January 8,1642
 
 

 Galileo was not destined to be a mathematician or to be
involved in the sciences; his father wanted him to be a
physician, so that he could make more money for the family.
There was no way that Galileo was not going to be a
mathematician; after hearing a lecture on geometry and reading some
of archimedes's works he decided it was the area he wanted to
pursue. Galileo actually found the method in which to regulate a
clock he just could never get the solution, he also attempted to
measure temperature using a thermal-scope (it was really inaccurate
and it was not until a century later until was something cemented in
temperature). Galileo made an instrument with a magnifying power of
32 this was called the "telescope," and thus began the age of
telescopic or optical astronomy.
 
 

Kepler, Johann born December 27,1571;  died  November 15,1630
 
 

 Kepler reinvented the solar system with his three
laws. His first law stated that the orbits of the other planets
could also be drawn as ellipses with the sun always at one of
the foci. His second law was that a line connecting a planet
and the sun will sweep over equal areas in equal times as the
planet moves about its orbit, this meant that the closer the
planet was to the sun, the faster that planet would move.
Kepler's third law said that the square of the period of
revolution of a planet is proportional to the cube of its
distance from the sun. In all three of his laws the sun seems to be the controller of planetary motion . Kepler's idea of the solar
system has been followed by astronomers ever since.
 
 

Picard, Jean born July 21,1620; died July 12,1682
 
 

 Picard was the first to put the telescope to use and not merely
for simple observations but for accurate measurements of small
angles. This helped cause astronomy to enter the area of quantitative
measurement. Picard is mostly known for the measurement of
the earth's circumference, a measurement more
accurate than that of Eratosthenes nineteen centuries earlier.
Picard used Eratosthenes notes and substituted a star for the
sun which made greater accuracy of measurement possible. The
measurements were 24,876 miles a radius of 3950 miles and a
degree a longitude at the equator of 69.1 miles.
 
 
 
 

Newton, sir Isaac born December 25,1642; died March 20,1727
 
 

 Newton invented the famed three laws of motion
which explained the motions of the heavenly bodies and their
gravitational pulls and other notions relating to astronomy. His first law of motion is that heavenly bodies moved
because nothing existed in outer space to stop them after the
initial impulse (Big Bang Theory). Newton's second law of motion defines a force
in terms of mass and acceleration and this was the first clear
distinction between the mass of a body or in other words how
much inertia it possesses and its weight representing the amount
of gravitational force between itself and another body. His
third law of motion says, that for every action there is an equal
and opposite reaction. The third law is most important today
because it deals with rockets (action reaction), Newton foreshadowed modern
aeronautics.
 
 

Halley, Edmund born November 8,1656; died January 14, 1742
 
 

Halley went down to St. Helana in the south pacific to establish
the first observatory ever in the southern hemisphere. Because
St. Helena had a bad climate, Halley was only ably to publish a
catalogue of 341 southern stars. This was nevertheless a new and
worthy addition to star lore and made his reputation. He was
called the "southern Tycho". Halley started to study comets, one
comet he observed was in 1682. By 1705 he had listed the
movements of nearly two dozen comets he was struck with the
similarity of the path of the 1682 comet with those that had
appeared in 1456,1531, and 1607. These four came in intervals of
seventy-five or seventy-six years and it occurred to Halley
that what he was dealing with was a single comet in a closed but
very elongated orbit about the sun that was visible only when it
was relatively close to the earth. Halley predicted that the
same comet would return in 1758, although Halley didn't live
long enough to see the comet. This comet was properly named Halley's comet.
 
 

Celsius, Anders born November 27, 1701; died April 25, 1744
 
 

 Celsius studied the aurora borealis and was the first to
associate it with changes in the earth's magnetic field. He was
the first to test the magnitude of the stars by measuring the
intensity of their light by a device other than the human eye.
This was all Celsius did for astronomy, dying at an
early age.
 
 

Priestley, Joseph born March 13,1733; died February 6,1804
 
 

 Priestley, was friends with Benjamin Franklin, and studied under
Him, doing research in the field electricity. He was the first to discover
that carbon was nonconductor, he also was the first to
suggest that electricity would prove to be important to
chemistry. Priestley discovered carbon dioxide in water and since it
tasted good, it is now known as soda water; Priestley may be
known as the founder of the modern soft-drink industry. He found
new gases such as ammonia, sulfur dioxide, and hydrogen
chloride. Priestley, by having mercury heated, discovered that in air it will form a brick red calx (which we now call mercuric oxide). Also discovered "dephospholigized air" or air the cannot support flame, due to the absence of an oxidizer, oxygen.
 
 

Dalton, John born September 6, 1766; died 27, 1844

 Dalton was the first to describe color blindness (he was color
blind himself). Dalton contributed to the theory of gases by
promulgating what is now known as Dalton's law of partial
pressures. This says that each component of mixture of gases
exerts the same pressure that it would if it alone occupied the
whole volume of the mixture, at a constant temperature. Dalton was
the first to advance a quantitative atomic theory. From the
proportions by weight of the elements in particular compounds.
Dalton even tried to work out the relative weights of all the
different atoms. He was the first to prepare a table of atomic
weights.
 
 

Sagan, Carl born November 9, 1934; 
 
 

 Sagan is interested in planetary surfaces and atmospheres. He
worked out a greenhouse model for the atmosphere of Venus,
accounting for the unusual high temperature of the planet. He also
found evidence for elevation differences on the surface of Mars
and for organic molecules in the atmosphere of Jupiter. He has
tried to form compounds from a system that reflects the conditions
of the primordial earth. Sagan has successfully explained what
astronomy can do for the average person and that it is
interesting and worth looking into. He has given astronomy fame and respect in the twentieth century.