Despite A Small Crew, Orbital Science Operations Continue
The Pore Formation and Mobility Investigation (PFMI) science team completed its third and fourth experiment runs this week in an effort to learn more about how bubbles can weaken materials such as those used in semiconductors and jet engine turbine blades.
Flight Engineer Peggy Whitson initiated the third run on Monday. After it was completed on Tuesday, Whitson removed the sample for return to Earth and installed a fourth sample that was completed early Wednesday.
When scientists melt metals on earth, bubbles that form in the molten material usually rise to the surface, pop and disappear.
However, some may remain and decrease a material's strength and usefulness. In microgravity, bubbles may move only slightly, making the Space Station a good place to study their movements and interactions.
PFMI employs a furnace to melt and re-solidify samples of a transparent modeling material called succinonitrile that allows scientists to watch bubbles form and control the conditions that affect bubble formation.
Information collected from PFMI is expected to provide insights into the processing of metals and alloys in space and on Earth.
The experiment is housed in the Microgravity Science Glovebox, a major new research facility delivered to the Station last spring, that safely contains potentially harmful materials during experiment operations.
It has a large front window with built-in gloves that allow astronauts to work safely with experiments and samples. Dr. Richard Grugel of NASA's Marshall Space Flight Center in Huntsville, Ala., is the principal investigator for PFMI.
"Our first two experiment runs were composed of pure succinonitrile," Grugel said. "Samples 3 and 4 this week are 'alloys' -- pure succinonitrile to which 0.38 percent water has been added. We expect to see different structures as a result."
Also on Monday, the crew took documentation photos of the soybean plants in the Advanced Astroculture (ADVASC) experiment. Plants, including mature seeds, grown during the mission will be returned to the Wisconsin Center for Space Automation and Robotics at the University of Wisconsin-Madison for study. The center is collaborating with Pioneer Hi-Bred International, Inc.
to study whether the space-grown plants produce seeds with different genetic properties useful in agriculture on Earth.
On Tuesday, Whitson and Commander Valery Korzun conducted their regular Pulmonary Function in Flight (PuFF) lung function test. Scientists are using the experiment to understand how the lungs can be affected by long-term exposure to microgravity, as well as the low-pressure environment of a spacesuit.
Selected crew members Wednesday filled out their weekly Crew Interactions survey on the Human Research Facility laptop computer. Interactions is a computer-based questionnaire intended to identify and characterize important interpersonal and cultural factors that may affect the performance of the crew and ground support personnel during Station missions.
Crew Earth Observation photography targets for this week included Congo-Zimbabwe biomass burning, the Nigerian coastal city of Lagos, and urban development in the Brazilian cities of Sao Paulo and La Paz.
The crew continued its daily payload status checks of automated science payloads to make sure that all experiments and payload facilities continue to operate properly.
The launch of Space Shuttle Atlantis has been postponed to no earlier than Monday, Oct. 7, while weather forecasters and the mission management team assess the possible effect Hurricane Lili may have on the Mission Control Center located at Johnson Space Center in Houston.
ISS Science Operations News
PFMI Fact Sheet
Glovebox Fact Sheet
Marshall Space Flight Center
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At its September meeting at the Jet Propulsion Laboratory, the NASA Advisory Council heard a good deal about the U.S. Mars program and about NASA's attempt to integrate itself with the U.S. educational system.