STS-94 Day 10 Highlights
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- On Thursday, July 10, 1997, 6:00 a.m. CDT, STS-94 MCC Status Report # 18
- More than one week into the STS-94 mission, the seven crewmembers
aboard Columbia are continuing their around-the-clock science
investigations in the Spacelab module, focusing on how various
materials and liquids change and behave in a microgravity environment.
- After a brief handover with their blue team counterparts just after
midnight, the red team members -- Commander Jim Halsell, Pilot Susan
Still, Mission Specialist Don Thomas and Payload Specialist Greg
Linteris -- took over responsibility for the management of science
operations aboard the Shuttle.
- About the same time as the red team began their Flight Day 10
activities, NASA astronaut Michael Foale, aboard the Russian Mir space
station, received a phone call from NASA Administrator Daniel Goldin.
During their conversation, Foale talked about the activities he and
his two cosmonaut crewmates have been engaged in since a Progress
vehicle collided with the Spektr science module last month. Foale
showed some of the hardware that will be used later this month, during
an intervehicular spacewalk, to restore power connections to the 3
undamaged Spektr solar arrays.
- Aboard Columbia, Halsell continued with his status checks and video
documentation on some of the Microgravity Science Laboratory (MSL)
experiments while Still monitored various orbiter systems. The two
science members of the red team, Thomas and Linteris, continued their
efforts with the 30-plus different experiments being carried in the
Spacelab module. Thomas' efforts this morning were with the Glovebox
unit and the Bubble Drop & Nonlinear Dynamics experiment while
Linteris worked with the Droplet Combustion Experiment.
- Thomas and Linteris are both scheduled for a half day of off-duty
time this afternoon. Half day rest periods are built into the crew
schedule during long duration spaceflights like STS-94 so that the
astronauts can remain well rested and operate at peak efficiency.
- While he is relaxing this afternoon, Thomas will take a few minutes
to talk with high school students from the greater Cleveland area who
will be gathered at the Great Lakes Science Center. The conversation
between Thomas and the students is scheduled for 11:22 a.m. CDT.
- The STS-94 Blue team, Payload Commander Janice Voss, Mission
Specialist Mike Gernhardt and Payload Specialist Roger Crouch, will be
awakened just after 11 a.m. today, to start their next day of orbiter
and science operations. The blue team will take over responsibility
for science and orbiter operations shortly after 1 p.m.
- On Thursday, July 10, 1997, 7:00 a.m. CST, STS-94 Payload Status Report # 15
- The crew of the Microgravity Science Laboratory mission and science
teams on the ground worked steadily through the night, continuing to
conduct fundamental scientific research in the areas of combustion
science, fluid physics, materials science and biotechnology.
- Payload Commander Janice Voss worked in the Combustion Module last
night to conduct an experiment to study the burning processes of very
weak mixtures of fuel and air in low-gravity. During the experiment, a
mixture of hydrogen, oxygen and sulfur hexafluoride -- a combination
that does not readily ignite -- was used in the facility. "We were
able to get it to burn. The burn and reburn were both extremely
successful," said investigator Paul Ronney of the University of
Southern California in Los Angeles. This is significant because these
are the weakest flames ever burned. They are will not burn on Earth.
- Findings from this study may be used to build better models of weak
combustion processes which may be applied to the design of cleaner,
more efficient-burning fuel engines. "We know that if we can burn
weaker mixtures in our engines, we could indeed get higher fuel
efficiencies, with lower pollutant formation," said Ronney.
- Overnight, Payload Specialist Dr. Roger Crouch and Mission
Specialist Dr. Donald Thomas conducted two tests of the Bubble and
Drop Nonlinear Dynamics experiment in the Middeck Glovebox. During the
experiment, acoustic pressure, or sound, is used to position the
bubble in the center of a water-filled container and then flatten
it. Researchers are measuring the bubble's movement as the shape of
the bubble changes. "This reveals the mechanical properties of the
bubble under large forces, or distortions," said investigator
Dr. Anthony Hmelo of Vanderbilt University in Nashville, Tenn. "These
properties are very difficult to model, so we are conducting this
study to better understand fluid physics in general and improve
- Findings from this investigation may also have applications for
improving industrial processes. "There are a range of industrial
processes that depend on drops for operation," said Hmelo. "For
instance, the combustion of fuels, the same processes being studied in
other experiments aboard Spacelab, depends on the kinds of fluid
physics we are investigating in the Middeck Glovebox."
- Crouch performed a scheduled disk change-out in the Quasi-Steady and
Space Acceleration Measurement system. The system is one of four on
board the Shuttle which detects and records the small, unavoidable
disturbances in the near-zero gravity of the environment of the
Spacelab. Science teams rely on the information, downlinked in
near-real-time, to determine the effect of the disturbances on
- In the Large Isothermal Furnace last night, Crouch began the fourth
of six planned runs of an experiment to study the diffusion process of
tracers, or impurities, in molten semiconductors. Diffusion is the
process by which liquid metals mix without stirring. The experiment is
a fundamental scientific study to measure the thermophysical
properties of germanium, an element widely used as a
semiconductor. Findings from the study may have applications for
improving the performance of electronic components made from
semiconductor materials, such as transistors and integrated circuits.
- Early this morning, Payload Specialist Dr. Gregory Linteris reported
"fantastic" burns in the Droplet Combustion Experiment. During the
experiment, heptane fuel droplets are burned at different pressures
and oxygen concentrations. Runs conducted this morning were at
one-half atmospheric pressure, half of what it is one Earth, in oxygen
concentrations varying from 25 to 40 percent.
- Results of each test may be different depending on the pressure,
oxygen and size of the droplet. "Three things can happen," said
project scientist Dr. Vedha Nayagam of NASA's Lewis Research Center
in Cleveland, Ohio. "The droplet can not ignite; it can ignite and
burn out partially, leaving a droplet of fuel; or it can ignite and
consume the droplet, burning out completely." The Droplet Combustion
Experiment is studying these scenarios.
- The experiment is also interested in determining the complex
chemical processes which occur when the flames are extinguished. "By
understanding the chemistry which occurs, we can burn them more
cleanly, more efficiently, because we know how they work," said
- Later, Linteris began an experiment in the TEMPUS levitating furnace
facility to collect fundamental measurements of an undercooled sample
of palladium-silicon. Undercooling is when a liquid remains fluid when
cooled below its freezing point. During the experiment an
electromagnetic pulse is used to squeeze, then release the sample
being levitated in the facility. Researchers then gather data on the
oscillations, or changes in the sample's shape. "By measuring the
oscillations, we can determine the surface tension and viscosity, or
resistance to flow," said researcher Bob Hyers of the Massachusetts
Institute of Technology in Cambridge, Mass.
- "We are using a new technique which is allowing us to measure the
viscosity of these samples for the first time, measurements which
can't be obtained on Earth. And even some of the surface tension
measurements are a first," said Hyers. This information may be used to
improve materials processing techniques on Earth and in turn products
manufactured from these processes. "The study is providing us with
fundamental measurements for modeling industrial materials
systems. Without the right parameters, you can't model systems," said
- Ahead, Linteris will continue to conduct the Droplet Combustion
Experiment and the fifth run of the diffusion of molten semiconductors
experiment will be initiated in the Large Isothermal Furnace.
- On Thursday, July 10, 1997, 5:00 p.m. CDT, STS-94 MCC Status Report # 19
- Science activities are continuing on board Columbia as the
seven-member crew supports a steady pace of investigations focusing on
flames, combustion, and plant growth on orbit.
- After a brief handover with their red team counterparts about 1 p.m.
central time today, the blue team astronauts - Payload Commander
Janice Voss, Mission Specialist Mike Gernhardt and Payload Specialist
Roger Crouch - assumed responsibility for the management of science
and orbiter operations.
- Throughout the afternoon and evening hours, Voss and Crouch will
support investigations in the Combustion Module and Glovebox
facilities, while Gernhardt monitors orbiter systems and conducts
video documentation of Spacelab operations. Late in the red team's
day, Gernhardt and Crouch will take time out from their investigations
for an interview with the CBS program "Up to the Minute." That
interview is expected to occur about 12:15 a.m. central time Friday.
- Before relinquishing responsibility to the blue team, the
four-member red team of astronauts completed another day of scientific
investigation. Mission Specialist Don Thomas and Payload Specialist
Greg Linteris both enjoyed some scheduled off-duty hours this morning,
to ensure they remain well rested during this planned 16-day mission.
Thomas took a few minutes this afternoon to talk with students who
gathered at the Great Lakes Science Center in Thomas' hometown of
Cleveland. Thomas answered questions about his preparations for the
STS-94 mission, the science he is conducting on board, and his Ohio
- The red team astronauts -- Commander Jim Halsell, Pilot Susan Still,
Thomas and Linteris -- will be awakened just after 11 p.m. today to
start their next day of orbiter and science operations.
- Columbia is continuing to fly virtually trouble-free, providing a
stable platform for science operations.
- On Thursday, July 10, 1997, 6:00 p.m. CST, STS-94 Payload Status Report # 16
- The study of fire dominated the Microgravity Science Laboratory-1
investigations in Columbia's Spacelab, today.
- This morning Payload Specialist Dr. Greg Linteris completed a run in
the second phase of the Droplet Combustion Experiment. The run is
part of a three phase study to map the burning characteristics of
heptane fuel droplets over a range of atmospheric pressures. The
first phase --conducted earlier in the mission -- burned fuel droplets
at one atmospheric pressure, the same as on Earth. The second phase
burned the droplets at one-half atmospheric, while the third will burn
droplets at one-quarter atmospheric pressure.
- "In each phase, we are keeping the pressure the same and slowly
reducing the oxygen to see if the fuels can still burn and if so, how
they burn," said project scientist Dr. Vedha Nayagam of NASA's Lewis
Research Center in Cleveland, Ohio. "On Earth, we encounter low
combustion scenarios -- for instance, in gas turbines -- so it's
important to know what happens when pressure is reduced."
- "We wanted to expand our data base at one-half atmospheric
pressure," said co-investigator Dr. Fred Dryer of Princeton University
in Princeton, New Jersey, "so we combined two of our gas bottles that
had been slated for one-quarter atmospheric pressure studies to yield
a one-half atmospheric condition in the test chamber." The
one-quarter atmospheric runs are scheduled for later in the mission.
- Linteris burned three sizes of heptane droplets -- 4 mm, 3 mm and 2
mm. The 4 mm droplet extinguished after burning 5.9 seconds--leaving
behind a relatively large droplet. The smallest droplet burned about
nine seconds -- using almost all of the fuel.
- "The large droplet extinguished early in its burn time due to loss
of significant combustion energy by radiation," said Dryer. "The
small droplet burned to near completion because less energy is lost by
radiation as the droplet's initial diameter is decreased. We would
have received opposite results if we'd conducted this same experiment
- Basic knowledge gained by the mapping of these various burning
regimes will be used by scientists to design better combustion
systems, such as combustors and propulsion systems, to extract maximum
efficiency while minimizing unwanted pollutants.
- After Linteris completed the series of runs to study burning fuel
drops, both he and Mission Specialist Dr. Don Thomas took a planned
- Late this morning, a palladium-silicon sample completed an 11-hour
processing period in the TEMPUS levitating furnace facility. The
sample went from a solid state to a molten state and then was
undercooled 16 times. The co-investigator, Bob Hyers of the
Massachusetts Institute of Technology in Cambridge, Massachusetts,
said this particular sample was chosen because it is a glass forming
metal with many industrial applications.
- "Preliminary results look very promising," said Hyers. "We got a
wide range of temperatures and achieved a reasonable amount of
- A sample of palladium copper and silicon is now processing in the
levitation furnace. Knowledge gained from this study, led by Dr. Ivan
Egry of the German Aerospace Research Establishment in Cologne, may be
used to improve materials processing techniques on Earth, and in turn,
products manufactured from these processes.
- Early this evening Payload Commander Dr. Janice Voss performed a run
of the flame ball experiment using a 4 percent hydrogen in air fuel
mixture. "The rich fuel mixture matches the lean flammability limit
of combustion on Earth," said project scientist Dr. Karen Weiland of
NASA's Lewis Research Center in Cleveland, Ohio.
- Voss' sparking attempt resulted in eight flame balls. By studying
flame balls, scientists hope to understand the physics of near-limit
combustion, thereby leading to the design of leaner-burning fuels and
improvements in engine efficiency - along with reduced emissions. The
Structure of Flame Balls at Low Lewis-number experiment is led by
Dr. Paul Ronney of the University of Southern California in Los
- This afternoon, Payload Specialist Dr. Roger Crouch performed the
Bubble Drop and Non-linear Dynamics Experiment led by Dr. L.G. Leal of
the University of California at Santa Barbara. During the experiment,
Crouch deployed a bubble into the center of a water-filled container
and then flattened it. On the ground the science team measured the
bubble's movement as the shape of the bubble changed--revealing
mechanical properties of the bubble under large forces or distortions.
Later, Crouch will deploy two bubbles and try to create one bubble
from the two--shedding light on bubble control and
manipulation. Results of the bubble experiment could lead to
techniques that eliminate or counteract the complications that bubbles
cause during materials processing.
- Processing of a germanium sample to study diffusion processes in
molten semiconductors ended this morning when the control
thermocouple, or temperature sensor on the sample, malfunctioned. The
sensor inadvertently told the furnace to heat the sample beyond the
high temperature limit which caused the Large Isothermal Furnace to
shut itself off. The furnace is designed to monitor temperature and
will shut off automatically if a sample reaches a certain temperature.
The science team on the ground says the Large Isothermal Furnace is
operating normally, and are assessing the control thermocouple which
is part of this particular sample run. The orbiter crew initiated
another scheduled sample run of the experiment at 5:15 p.m. -- after
the furnace had cooled down. This run is proceeding normally.
- Ahead, Voss will conduct another run of the flame ball experiment
and Crouch will continue the bubble experiment.
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