STS-83 Day 4 Highlights
Back to STS-83 Flight Day 03 Highlights:
- On Monday, April 7, 1997, 7:00 a.m. CST, STS-83 Payload Status Report # 05
reports: (MET 02/16:39)
- Spacelab crew members and science teams at Marshall Space Flight
Center in Huntsville, Ala., worked steadily through the night to
complete as much science as possible in the remaining hours of the
mission. Due to a malfunction in the Space Shuttle's number two fuel
cell, Columbia is now scheduled for landing Tuesday afternoon.
- The abbreviated mission came as a disappointment to participating
scientists. The atmosphere, however, was also marked by bright spots,
such as the excitement of one science team which recorded a
"first" in combustion research. Payload Commander Dr. Janice
Voss completed several runs of the Droplet Combustion Experiment last
night. "Six burns were successful and for the first time, we're
burning free droplets" said Principal Investigator Dr. Forman
Williams of the University of California at San Diego.
- The experiment is collecting information on burning rates of flames,
flame structures and conditions under which flames are
extinguished. "We can't get this kind of information from
ground-based experiments" said Williams. "We have burned at two
different atmospheres of oxygen concentration and calculated the
burning times of free fuel droplets at each."
- Combustion of fuel droplets is an important element in heating
furnaces for materials processing, heating homes and businesses, and
producing energy in gas turbines and gasoline-powered
engines. Findings from this investigation are providing researchers
with a better understanding of the combustion process and may lead to
cleaner and safer ways to burn fossil fuels as well as more efficient
methods of generating heat and power on Earth.
- The Coarsening in Solid-Liquid Mixtures experiment continued to run
in the Middeck Glovebox facility. This investigation, led by Dr. Peter
Voorhees of Northwestern University in Evanston, Ill., is studying
coarsening in metal mixtures at very high temperatures. During
coarsening, small particles shrink by losing atoms to larger
particles, resulting in a lack of uniform particle distribution. This
weakens the material and shortens its life-span.
- "Because of our small size and power usage we've been able to
continue experiment runs, completing four runs with good success"
said John Caruso, project manager for the experiment, with NASA's
Lewis Research Center. "From the engineering data we've
received, we expect to get satisfactory science. We expect the samples
will show uniform particle distribution."
- Findings from this research may lead to improved manufacturing
processes and stronger, longer-lasting materials.
- Early Sunday evening, Payload Specialist Dr. Roger Crouch began a
study of the Structure of Flame Balls at Low Lewis-number, called
SOFBALL, in the Combustion Module. The study is designed to determine
under what conditions a stable flame ball can exist and if heat loss
is responsible in some way for the stabilization of the flame ball
- "The two completed runs were successful beyond my wildest dreams"
said Principal Investigator Dr. Paul Ronney of the University of
Southern California in Los Angeles. During the first experiment, a
mixture of hydrogen, oxygen and carbon-dioxide burned in the facility
for the entire 500-second limit. This result is significant because
"these are the weakest flames ever burned -- lowest temperature,
weakest, most diluted mixtures" explained Ronney. "These mixtures will
not burn in Earth's gravity."
- "We have known that burning weaker mixtures increases efficiency"
said Ronney, "but not much is known about the burning limits of
these mixtures." Findings from this experiment will also provide
researchers with a better understanding of the combustion process and
will help to improve theoretical models. "Combustion models give
different results for these types of flames" said Ronney. "This
is an acid test to show which, if any, current combustion modules
should be used."
- The Experiment Control Systems Computer, which relays
ground-commands to the experiment facilities, malfunctioned. The
Spacelab crew performed a procedure to disconnect the computer from
the master timing unit, allowing the computer and experiments to go to
internal timing sources.
- In the electromagnetic containerless processing facility, called
TEMPUS, two experiment runs ended early when the undercooled,
levitated samples came in contact with the wall. Undercooling refers
to a liquid being cooled to a temperature below its normal freezing
point yet remaining in a liquid state -- like cooling a glass of
distilled water on Earth. However, if the glass is tapped or
disturbed, ice begins to form quickly -- just as the samples began to
solidify when they hit the wall. Another study of undercooled
materials was initiated in the facility. This experiment, which
measures the specific heat of undercooled metallic melts, is examining
how metallic glass forms in zirconium-based alloys.
- Before ending his shift early this morning, Crouch began another run
of the Liquid Phase Sintering experiment in the Large Isothermal
Furnace. This experiment is investigating how liquid metals form a
mixture without reaching the melting point of the formed metallic
alloy. Information gathered will provide researchers with a better
understanding of liquid phase sintering in low-gravity and comparisons
of findings to theoretical predictions, should improve theoretical
models. The principal investigator for the study is Dr. Randall German
of Pennsylvania State University in University Park, Pa.
- Dr. Donald Thomas and Dr. Gregory Linteris assumed science
operations aboard the Shuttle early this morning. Thomas completed
another run of the Liquid Phase Sintering experiment in the Large
Isothermal Furnace before beginning to deactivate protein crystal
- After completion of another run of the Droplet Combustion
Experiment, Linteris began reconfiguring the Droplet Combustion
Apparatus for return to Earth.
- Ahead, crew members will continue to deactivate experiment
facilities in preparation for the Shuttle's journey home.
- On Monday, April 7, 1997, 7:30 a.m. CST, STS-83 MCC Status Report # 7
- Microgravity research aboard the Shuttle Columbia neared an end this
morning as the astronauts prepared to check out the Shuttle's
flight control systems that will be used during tomorrow's landing
at the Kennedy Space Center
- Commander Jim Halsell and Pilot Susan Still will check out
Columbia's aerosurfaces which are used to control the Shuttle after
it reenters the Earth's atmosphere and will test fire the ship's
maneuvering jets used to steer the Shuttle while it is in space. The
tests will be completed before Red team crew members Halsell, Still,
Mission Specialist Don Thomas and Payload Specialist Greg Linteris go
to bed for what is expected to be their final sleep period on orbit.
- Blue team crew members Janice Voss, Mike Gernhardt and Roger Crouch
will finish up science activities this afternoon and will deactivate
Spacelab systems in the pressurized research module shortly after 9
- With Columbia's mission having been cut short because of a
voltage problem with fuel cell number 2, which was shut down and safed
yesterday, the astronauts will spend part of the day stowing their
crew cabin for their return to Earth tomorrow. All of Columbia's
other systems are functioning in excellent condition, including the
two remaining fuel cells which are carrying the load of electrical
production for the orbiter and the Spacelab.
- Columbia and its crew are scheduled to return home tomorrow
afternoon. The deorbit burn to drop Columbia out of orbit is
scheduled for 12:35 p.m. Central time. Landing at Kennedy Space
Center's Shuttle Landing Facility would take place one hour later
at 1:35 p.m. with additional opportunities available on subsequent
orbits to their KSC or the backup landing site at Edwards Air Force
- On Monday, April 7, 1997, 5:00 p.m. CST, STS-83 MCC Status Report # 8
- Columbia's seven astronauts spent what should be their last full day
on orbit preparing to close down science operations and ready their
vehicle for a Tuesday landing at the Kennedy Space Center.
- This morning, mission commander Jim Halsell and pilot Susan Still
conducted a routine pre-entry check of Columbia's flight control
systems and performed a hot fire test of the reaction control system
jets. One jet, designated F3F, failed off during the test, but does
not affect reentry plans since redundant jets perform the same
function as the failed jet.
- Halsell and Still, together with their Red Team partners Don Thomas
and Greg Linteris, participated in a crew news conference talking with
media in Houston, Florida and Alabama. The crew remarked that while
the short mission was a disappointment to them, they feel significant
science had been accomplished in the few days of Spacelab operations.
- On the ground, flight controllers continue to manage electrical
power loads on the spacecraft. They also performed troubleshooting
procedures on an experiment control computer for the Spacelab module
and on the minus-Y startracker, part of the Shuttle's navigation
system. One of two startrackers, the minus-Y unit showed indications
that it was not communicating properly with other components and,
after troubleshooting procedures were run, was considered failed.
There is no impact to the mission since the remaining minus-Z
startracker continues to perform well and the startrackers are
designed to work independently of one another to provide information
to Columbia's Inertial Measurement Units.
- Columbia and its crew are scheduled to return to the Kennedy Space
Center on Tuesday afternoon. The deorbit burn to drop Columbia out of
orbit is scheduled for 12:31 p.m. Central time. Landing at Kennedy
Space Center's Shuttle Landing Facility would take place one hour
later at 1:33 p.m. with additional opportunities available on
subsequent orbits to either KSC or the backup landing site at Edwards
Air Force Base, California. Weather appears acceptable at both sites,
although crosswinds will be near normal limits.
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