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.