LMS Public Affairs Status Report #15
Noon CDT, July 4, 1996
MET 014/02:11
Spacelab Mission Operations Control
Marshall Space Flight Center

	There were no fireworks, just a normal busy day of 
experiments for the crew of the Space Shuttle Columbia as it 
crossed the two-week point this Independence Day on the way 
to completing its record-setting 17-day mission.  However, 
right after lunch crew members did take an opportunity to 
play a few patriotic songs and wish Americans on Earth a 
happy Fourth of July.

	It was evident to all that the closing days of the mission were at hand as the crew members prepared to run a final planned experiment through the Bubble, Drop and Particle Unit, and investigators on the ground monitored the 
processing of a final planned experiment in the Advanced 
Gradient Heating Facility.

	Pilot Kevin Kregel and Payload Commander Susan Helms 
successfully performed an in-flight maintenance procedure on 
the Bubbles and Drops Interaction with Solidification Fronts 
experiment cartridge and inserted it into the Bubble, Drop 
and Particle Unit.  

	Designed by Dr. Rodolfo Monti of the University of Naples,
Italy, the experiment first examines the interaction of gas bubbles,
and then liquid drops, against the leading edge of a solidifying waxy
substance.  The first half of the study focusing on bubbles was
successfully completed Tuesday.  The second half focusing on drops was
to have run immediately after the first; however, during the water
drop phase, investigators discovered a water injector would not
retract from its deployed position, prompting the cartridge's
removal. Engineers on the ground quickly developed a solution to what
was determined to be a minor electrical problem, and the crew members
completed the procedure without a hitch this morning.  Results of the
Monti experiment -- the final of 14 carried out as planned throughout
the flight -- may help researchers learn how to prevent flaws created
by gasses released as glass and crystal solidify.

	Before performing the scheduled in-flight maintenance 
procedure on the Bubble, Drop and Particle Unit, Helms and 
Kregel removed an experiment led by Dr. Johannes Straub of 
the Technical University in Munich, Germany, from the unit.  
This investigation -- which began its second run of the 
mission Tuesday following the first half of the Monti 
experiment -- examined heat transfer as a liquid refrigerant 
was brought to the boiling point.  The research could lead to 
the creation of cooling systems for small high-powered 
electronic devices, such as computer chips.

	An aluminum-indium sample continued to be processed today in
the Advanced Gradient Heating Facility.  The experiment, led by
Principle Investigator Dr. Barry Andrews of the University of Alabama
at Birmingham, studies the segregation of alloys as they solidify.
Its aim is to help researchers develop ways to control the internal
structure of alloys during processing.

	Today was a busy day for crew members using the Torque
Velocity Dynamometer, a multi-use exercise machine designed to test
muscle strength in various parts of the body.  This morning, Payload
Specialist Dr. Jean-Jacques Favier and Mission Specialist Dr. Richard
Linnehan resumed arm, hand-grip and leg strength tests on the
dynamometer, while Mission Specialist Dr. Charles Brady performed arm
strength tests, and Payload Specialist Dr. Robert Thirsk performed
hand-grip tests. Before the leg strength tests, both Favier and
Linnehan attached electrodes to their left legs which applied precise
electrical stimuli to cause involuntary muscle contractions.

	Thirsk and Favier also exercised on a stationary bicycle-like
device called the ergometer.  Exercising on the ergometer during the
mission not only helps the crew members maintain cardiovascular
conditioning in the microgravity environment, but it also helps
researchers gather data on in- flight muscle atrophy. Information from
the various dynamometer and ergometer operations today may help
investigators determine why muscles lose strength in a microgravity
environment.

	Thirsk, Henricks, Favier and Kregel today also continued their
tests on the human behavior workstation, which they've conducted on
alternate days throughout the mission.  A laptop computer displays a
series of problem-solving exercises which help track each crew
members' level of mental fatigue.

	Researchers hope to use the results of the continuing study to
plan future crew schedules that take advantage of periods of peak
mental performance.

	Brady, Favier, Thirsk and Linnehan also brought to a close the
final 72-hour period in the Sleep and Circadian Studies. The study
looks at how life in space affects sleep patterns, circadian rhythms
and mental alertness.  The crew members completed questionnaires at
the beginning and end of their day, as well as alertness and mood
tests before each meal and throughout the morning.  A similar 72-hour
period was completed earlier in the flight.

	Helms, Kregel, Thirsk and Favier continued the Astronaut Lung
Function Experiment to measure the effects of microgravity on the
pulmonary system during rest, heavy exercise and deep breathing. All
four crew members wore electrodes to monitor their heart activity, and
all but Helms wore the vest-like Respitrace Suit to monitor chest and
abdomen motions during breathing as they conducted the studies.


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