STS-94 Day 9 Highlights
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- On Wednesday, July 9, 1997, 6:00 a.m. CDT, STS-94 MCC Status Report # 16
- As shuttle mission STS-94 nears the halfway point, Columbia
continues to orbit the Earth in excellent condition, providing a
stable and reliable platform for more than 30 separate scientific
investigations. The official halfway point of the Microgravity
Science Laboratory mission will occur later this morning, just before
9:30 a.m. central, at 7 days, 20 hours and 26 minutes into the flight.
- Following a brief handover with their blue team counterparts just
after midnight, Columbia's red team crew 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.
- After starting his day with an exercise period, Halsell conducted
status checks and video documentation on some of the Microgravity
Science Laboratory experiments and activities being carried in the
Spacelab module. The first part of Pilot Susan Still's day
involved monitoring orbiter systems and finishing troubleshooting on
the Shuttle Amateur Radio Experiment (SAREX). Still reported just
before 3 a.m. today that she was seeing a good connection between the
SAREX system, the Payload General Support Computer (PGSC) and the
Packet Module. This interface means that SAREX operations data, such
as who contact is made with, the time of contact and other
information, will be recorded in the laptop computer.
- Halsell and Still also spent part of their morning setting up and
collecting data with the Wireless Data Acquisition System (WDAS). The
WDAS is a risk mitigation experiment designed to gather orbiter cargo
bay temperatures and monitor if payload hardware is approaching
thermal limits. It is believed that real-time monitoring of thermal
conditions for various exterior payloads on the future International
Space Station may be required and a system such as WDAS might provide
the support needed.
- Thomas and Linteris spent their morning in the Spacelab module
working on several experiments. Thomas' has been working with the
Large Isothermal Furnace (LIF), a vacuum-heating furnace designed to
heat large samples uniformly; the Middeck Glovebox (MGBX) unit; and
the Internal Flows in a Free Drop Experiment (IFFD). The IFFD
experiment involves containerless processing of materials using
acoustic positioning techniques. Linteris has worked with the
Combustion Module and an experiment called the Structure of Flame
Balls at Low Lewis-number (SOFBALL). Data from the SOFBALL experiment
could lead to improvements in lean-burning internal combustion engines
that may increase their efficiency and reduce emissions.
- At 7:22 a.m. central today, Halsell and Still will take a few
minutes away from orbiter activities to conduct an interview with
WRDW-TV and WJBF-TV in Augusta, Georgia, the hometown of Still.
During the remainder of their day, both Halsell and Still will conduct
communication sessions with the SAREX. Thomas will continue his work
with the Glovebox unit while Linteris continues his work with the
- The Blue team of crew members, Payload Commander Janice Voss,
Mission Specialist Mike Gernhardt and Payload Specialist Roger Crouch,
will awaken at about 11 a.m. and relieve the Red team at 1
- On Wednesday, July 9, 1997, 7:00 a.m. CST, STS-94 Payload Status Report # 13
- Aboard Spacelab last night, Payload Commander Dr. Janice Voss
ignited the first flames of the flame ball experiment. The purpose of
the investigation is to determine if stationary spherical flame
structures can exist. "It was just fantastic," said Microgravity
Science Laboratory investigator Paul Ronney of the University of
Southern California in Los Angeles. "We had two very successful
burns. Everything worked great and we are just ecstatic."
- During both runs, mixtures of hydrogen, oxygen and sulfur
hexafluoride burned in the chamber for the full 500-second duration of
the test. This is significant because these mixtures will not burn on
Earth. "These are the weakest flames ever burned," said Ronney. "The
typical power of these flames is about one watt, less than a
- The experiment revealed new information about the role of buoyancy
on flames. "The effect of gravity is weaker than we expected," said
Ronney. And that information, along with other findings from the
study, may have important applications for improving fuel efficiency
on Earth. "If we could burn weaker mixtures in engines, we could get
higher efficiency with less pollutant emissions," said Ronney.
- This morning, after the crew shift change, Payload Specialist
Dr. Gregory Linteris continued the flame ball experiment, reporting
"phenomenally successful" runs.
- Two runs of the Internal Flows in a Free Drop experiment were
completed overnight in the Middeck Glovebox. Payload Specialist
Dr. Roger Crouch conducted the first run late last night, and Mission
Specialist Dr. Donald Thomas completed another run early this
morning. The experiment examines techniques for controlling the
position and motion of liquids in low-gravity. This study is allowing
researchers to assess a potential method of mixing which could lead to
improvements in chemical manufacturing, petroleum technology, and the
cosmetics and food industries.
- Late last night, Mission Specialist Mike Gernhardt performed a shear
cell rotation of the sample processing in the Large Isothermal
Furnace. A second rotation was performed by Thomas early this
morning. This procedure is part of an experiment to study the
diffusion process of tracers, or impurities, in melted germanium, an
element widely used as a semiconductor and alloying agent. "It is a
fundamental scientific study. We are trying to measure the
fundamental thermophysical properties of this semiconductor," said
lead scientist Dr. David Matthiesen of Case Western Reserve University
in Cleveland, Ohio.
- Such knowledge is fundamental and findings from this study may have
applications for improving the performance of electronic components
made from semiconductor materials, such transistors and integrated
- "We're using samples of pure germanium and doped germanium, or one
with an additive," explained Matthiesen. "The first shear rotation
brings samples into contact with other. After processing for a certain
amount of time, the second rotates them back to break them into
segments." The segments are then cooled for post-flight analysis.
- One thermocouple -- an electronic temperature sensor -- in the
cartridges used for Matthiesen's samples is not working. Researchers
are working on a procedure to correct the connection between the
facility and the thermocouple.
- In the TEMPUS levitating facility, an investigation is underway to
study nucleation, or the point at which solidification from the melted
state begins, in undercooled liquid zirconium. Undercooling is when a
liquid remains fluid when cooled below its freezing point. Researchers
are interested in determining the temperatures at which nucleation, an
important in metals casting processes, occurs.
- According to researcher Dr. Robert Bayuzick of Vanderbilt University
in Nashville, Tenn., the team is extremely pleased with last night's
test results. "The effort could be considered a complete success,"
said Bayuzick. Collaborating on the study with Bayuzick are Dr. Merton
Flemings and Dr. Gerardo Trapaga of the Massachusetts Institute of
Technology in Cambridge, Mass. Results may help improve theoretical
- Today, Thomas is slated to conduct a study in the Middeck Glovebox
to examines the manipulation of bubble shape and movement in water
under weightlessness conditions. He will also continue the diffusion
in semiconductors experiment under way in the Large Isothermal
Furnace. Linteris will continue the flame ball experiment in the
Combustion Module and begin another undercooling of metallic alloys
study in the TEMPUS facility.
- On Wednesday, July 9, 1997, 5:00 p.m. CDT, STS-94 MCC Status Report # 17
- A brisk pace of scientific investigation is continuing on board
Columbia as the STS-94 mission enters the second half of its planned
16-day stay on orbit.
- The official halfway point of the Microgravity Science Laboratory
mission occurred just before 9:30 a.m. central time today, at 7 days,
20 hours and 26 minutes into the flight. The seven-member crew
continues its around-the-clock science support studying how various
materials and liquids change and behave in the weightless environment
- Throughout the morning the Red team astronauts, Jim Halsell, Susan
Still, Don Thomas and Greg Linteris, supported investigations in the
Large Isothermal Furnace, Middeck Glovebox and other facilities in the
- This morning, Still talked with two television stations in her
hometown of Augusta, Georgia. In interviews with WRDW-TV and WJBF-TV,
she and Halsell discussed the progress of their mission to date and
the day-to-day housekeeping tasks performed on board.
- This afternoon at the request of the flight control team, Halsell
toggled a power supply switch for one of Columbia's aerosurface
servo-actuators (ASA's) that control various aerodynamic surfaces,
including the rudder and elevons. There are four ASA's on board, each
with redundant power supplies. The flight control team noticed that
ASA 4 had lost redundancy in one of its two power sources and
requested Halsell to perform the power cycle which restored full
redundancy and cleared the problem. The loss of one of the two power
supplies to ASA 4 would not have had any impact on the mission.
- The Red team began an eight-hour sleep period shortly after 3
p.m. central time.
- The Blue team of crew members, Payload Commander Janice Voss,
Mission Specialist Mike Gernhardt and Payload Specialist Roger Crouch,
assumed responsibility for orbiter and science operations shortly
after 1 p.m. central time. Voss and Crouch will continue work with
investigations in the Large Isothermal Furnace and Combustion Module.
Crouch is scheduled for about an hour and one-half of off-duty time
early in his day.
- On Wednesday, July 9, 1997, 6:00 p.m. CST, STS-94 Payload Status Report # 14
- "Great Balls of Fire" are just what Columbia's science crew saw
today in an experiment to study the simplest form of combustion. But
it wasn't their strength or size that made these flame balls great.
Today, astronauts were continuing an experiment that is resulting in
the weakest flames ever produced.
- Most of the fuel mixtures that are being used for this experiment
are so weak -- resulting in flames that are about one hundred times
weaker than a common match flame -- that they will not burn on Earth.
- Knowledge gained from this experiment will be used to build better
computer models of weak combustion that can be applied to the design
of more fuel efficient and cleaner engines. Researchers will also be
able to apply experiment results to spacecraft safety.
- "We're learning that there are certain types of fuel mixtures that
will burn in a space environment that couldn't burn on Earth. We can
use this knowledge to make the next generation of spacecraft even
safer," said Dr. Paul Ronney of the University of California in Los
Angeles, lead scientist for the Structure of Flame Balls at Low
- Both Payload Specialist Dr. Greg Linteris and Payload Commander
Dr. Janice Voss performed runs of the flame ball experiment today.
This morning, Linteris performed a run of the experiment using a fuel
mixture of 4.6 percent hydrogen in carbon dioxide, the most diluted
hydrogen/carbon dioxide mixture to be used. After the third sparking
attempt, what resulted were two balls of flame that burned for the 500
second duration of the experiment. Upon a reburn attempt the
remaining fuel mixture produced a single flame ball.
- "We're almost getting more data than we know what to do with, and
we're going to be spending a lot of time trying to analyze all of
this," said Ronney.
- Today, Mission Specialist Dr. Don Thomas and Payload Specialist
Dr. Roger Crouch conducted an experiment that could improve
manufacturing processes on Earth. Bubbles that form during the
processing of materials can cause many complications in a variety of
industrial applications, including the solidification of certain
alloys which involve systems where large number bubble and drop
dispersions are used.
- The Bubble and Drop Nonlinear Dynamics experiment, lead by
Dr. L.G. Leal of the University of California at Santa Barbara, will
help scientist better understand how bubbles respond to ultrasonic
radiation pressure -- possibly leading to a technique that could
eliminate or counteract the complications that bubbles cause during
- During the experiment, bubbles are deployed into a water-filled
chamber within the Glovebox. Scientists are assessing their ability
to control bubble location, manipulate double bubbles and maximize
bubble shape. Shape deformation is being studied as a function of
size and ultrasonic pressure. The effect of ultrasonic radiation
pressure on bubbles will also be assessed by bringing two single
bubbles together to form one.
- This afternoon, Linteris initiated an experiment in TEMPUS to
investigate the maximum amount that a sample of aluminum-copper-iron
and aluminum-copper-cobalt melts could be cooled below their freezing
point and remain liquid. The investigation, led by Dr. D.M. Herlach
of the German Aerospace Research Establishment in Cologne, Germany,
could shed light on nucleation, an important chemical and industrial
- The gum ball-size sample is covered with a thin layer of gold. "The
gold is protecting the sample from oxidation," explained Herlach. "If
the sample -- containing aluminum -- were to oxidize, it could not be
undercooled." As the gold-plated sample is processing, researchers
are measuring the specific heat of the melt, an important parameter
for modeling nucleation and growth processes, which could improve the
analysis of undercooling experiments performed in space as well as on
- Crew members from both shifts performed shear cell rotations of the
germanium sample processing in the Large Isothermal Furnace -- with
Thomas completing one shortly before noon and Voss performing one
rotation around 1:30 p.m. This procedure is part of an experiment to
study the diffusion process of tracers, or impurities, in melted
germanium, an element widely used as a semiconductor and alloying
- During the shear cell rotation, samples of pure germanium and
germanium with an impurity are rotated into contact with each
other. After an opportunity to mingle together, or diffuse, the
resulting single sample is sheared into segments and cooled for
- "This is the first time diffusion in semiconductors has been studied
in space. Diffusion of liquid metals has been studied before, but not
semiconductors. The difference is metals expand when melted and
semiconductors expand, like water, upon freezing. That subtle
difference made the development of technology to conduct this
experiment very difficult," said the study's principle investigator
Dr. David N. Matthiesen of Case Western Reserve University in
- At the beginning of his shift, Crouch successfully performed an
inflight maintenance procedure for the Large Isothermal Furnace. One
thermocouple -- an electronic temperature sensor -- in the cartridges
used for Matthiesen's samples was not working. After the procedure,
the ground crew began to receive data from the thermocouple again.
- This evening, Crouch will continue the bubble experiment and Voss
will perform another run of the flame ball experiment using the
richest fuel mixture yet to be burned.
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