ISS Science Operations Status Report for week ending July 17, 2002
Astronauts literally got their hands on a new tool for conducting research
aboard the International Space Station in the past week.
Checkout and activation of the Microgravity Science Glovebox (MSG), ferried
to the Station recently by Space Shuttle Endeavour, was completed and the
first scientific research began.
"We experienced some normal startup difficulties but nothing unexpected for
a new piece of equipment like this," said Charles Baugher, glovebox
discipline scientist for NASA’s Marshall Space Flight Center in Huntsville.
"We’ve begun our first experiment, the Solidification Using a Baffle in
Sealed Ampoules (SUBSA) experiment and we’re continuing to conduct Glovebox
science this week."
The SUBSA experiment is the first of two Expedition Five materials science
experiments that will study basic physical processes similar to those used
to make semiconductors for electronic devices and components used in jet
engines. Last week’s 16-hour experiment will be followed by a second SUBSA
test pending completion of additional non-sample testing this week. A total
of 10 samples will be processed during the Expedition. The principal
investigator for SUBSA is Aleksandar Ostrogorsky, associate professor of
mechanical engineering at Rensselaer Polytechnic Institute, in Troy, New
York.
For this investigation, quartz tubes called ampoules filled with indium
antimonide material previously solidified on Earth are placed in a furnace
inside the Glovebox, melted and then slowly cooled to re-solidify in
microgravity and form single solid crystals. Scientists want to study how
impurities – tellurium and zinc in this experiment – added to a
semiconductor to control its properties can be more uniformly distributed
throughout the material.
"I think my experiment went as nice as we expected or hoped," Ostrogorsky
said. "We had a minor computer/communication problem, which could be
expected, considering that both MSG and SUBSA are being used for the first
time. The clarity of images was excellent. The molten semiconductor
material was performing as we wanted, without separating from ampoule walls
or releasing undesirable bubbles that have been reported in several previous
microgravity investigations. A specific feature of SUBSA experiments is
that one can really see the semiconductor crystals growing for the first
time in space. In the previous Space Shuttle experiments, the investigators
had to wait for the samples to return to analyze the crystals, without
seeing the crystal grow. We want to get reproducible results The Shuttle
did not provide enough flight time to do a series of experiments that could
provide reproducible results."
The key feature of the phone booth-sized Glovebox rack is a sealed work area
with windows and built-in gloves on its sides and front. It was designed to
allow Station crews to work safely with experiments that involve fluids,
flames, particles and fumes that otherwise would be difficult to contain in
the near-weightless microgravity environment on the Station. A European
Space Agency industry team including ASTRIUM, Bradford Engineering,
Verhaert, and ATOS-ORIGIN developed the Glovebox for NASA.
The crew and ground controllers last Friday completed the first Expedition
Five sample run of the Zeolite Crystal Growth (ZCG) experiment. The samples
from the 15-day experiment remain in the furnace awaiting return on the next
Shuttle mission, while new samples will be shipped to the Station for a new
round of research. Samples processed in the ZCG furnace are expected to
lead to insights in electronic printing and transmitting electronic data.
Soybean plants inside the Advanced Astroculture experiment continued to grow
well during the past week. The crew continued to tend the plants on Monday,
adding new nutrient fluid and collecting gas and condensate samples for
analysis on the ground.
As part of their Crew Earth Observations photography research on Monday, the
crew participated in a multi-agency experiment called Cirrus Regional Study
of Tropical Anvils and Cirrus Layers – Florida Area Cirrus Experiment
(CRYSTAL-FACE). The experiment is designed to collect measurements of
clouds that will help improve climate models. The Station photos have the
potential to provide profound visuals for use in describing and interpreting
measurements by the other participating agencies. Scientists asked that
they downlink the digital images as soon as possible. Other CEO photography
subjects this week included air quality over the eastern Mediterranean, the
Nile River delta, fires in Angola, Florida thunderstorm anvils, lakes of the
eastern Sierra, high central Andean glaciers, and Lake Poopo in Bolivia.
On Thursday and Friday this week, the Expedition Five crew is scheduled to
conduct the Microencapsulation Electrostatic Processing (MEPS) experiment,
which is exploring an improved method of drug delivery. Five test runs are
planned for Thursday and three more for Friday. The automated experiment
will combine two liquids to form tiny liquid-filled bubbles surrounded by a
thin membrane. The device cures, filters, washes and harvests the
microcapsules for analysis on the ground. Experiments such as this could
eventually lead to the development of anti-tumor drugs that allow the
delivery of higher doses of chemotherapeutic drugs to specific treatment
sites, reducing the unwanted side effects experienced by cancer patients.
