Space station experiments return to Earth labs for study
Posted: July 28, 2001

Payload ground support teams were at Kennedy Space Center to greet Space Shuttle Atlantis when it landed late Tuesday and retrieve their experiments that have been onboard the International Space Station for more than three months.

Now on their way back to labs around the country for analysis are the Advanced Astroculture experiment, Protein Crystal Growth Single Thermal Enclosure Unit experiment, and the Commercial Generic Bioprocessing Apparatus experiment.

The goal of the Advanced Astroculture experiment, the first U.S. plant growth facility aboard the Station, was to grow plants through a complete life cycle - from seed to seed. When the Astroculture experiment returns to the University of Wisconsin-Madison, scientists will conduct physiology and morphology studies that include counting the number of seeds and leaves, growth height, weight and other factors, said Dr. Weijia Zhou, principal investigator for the experiment, with the Wisconsin Center for Space Automation and Robotics (WCSAR). The post-mission study also will include cell wall and chemical analyses.

The seeds are Arabidopsis, a member of the same plant family as cabbage, cauliflower and radishes. It was selected for the experiment by WSCAR's commercial partner, Space Explorers Inc., because of several advantages such as rapid life cycle, easy cultivation in restricted space, prolific seed production, extensive genetic maps and other factors. Such advantages have led Arabidopsis becoming the model organism for studies of the molecular genetics of flowering plants.

Most of the seeds will be turned over to Space Explorers, located in De Pere, Wisconsin. The company plans to incorporate the results obtained from the post mission analysis into its "Orbital Laboratory" Internet-based commercial education program. It also will use the seeds for other proprietary commercial ventures.

Some of the space-grown seeds will be used to conduct the second Arabidopsis life cycle experiment on the upcoming UF-1 Shuttle mission to the Station, which will produce a second generation of space seeds, Zhou said.

"That will allow us to study whether microgravity may have effects on the plant's genetic code," Zhou said.

The protein crystallization experiment is on its way back to Marshall Space Flight Center in Huntsville for analysis of biological samples grown during the mission. The Bioprocessing Apparatus will return to the University of Colorado in Boulder where the payload team will try to learn why it experienced a failure early in the mission.

Automated payloads onboard the Station continued operating during the past week, while crew activities focused on docked operations with Space Shuttle Atlantis. The crew continued to monitor experiment health and status to make sure experiments were operating normally.

The Protein Crystal Growth Enhanced Gaseous Nitrogen Dewar experiment transferred to the Station last week during the STS-104 Shuttle mission was placed in Zarya, the Russian FGB module, and is operating as expected. It is the last Expedition Two experiment to arrive on the Station.

On Saturday, July 21, the Microgravity Acceleration Measurement System recorded the Atlantis undocking. It also recorded the Shuttle docking last week. Scientists plan to compare the Station microgravity environment with and without the additional mass of an attached Shuttle. This information will be used by scientists planning future experiments that require a vibration-free environment and allow them to minimize the impact on their experiments.

During the past week, the Experiment on Physics of Colloids in Space conducted four scheduled operations. Two were used to downlink missing data files to the ground and perform some short science measurements to monitor any changes in four crystalline samples started in the past several weeks. The remaining two operations were used to mix the Colloid-Polymer Critical Point sample and begin studying its behavior. Scientists monitoring their experiment from the ground were able to obtain excellent data on the sample, which separated itself into two phases resembling a gas and a liquid.

A colloid is a system of fine particles suspended in a fluid. Paint, milk and ink are only some of the examples of colloid products routinely produced and used on Earth. Scientists hope to learn how to manipulate the physical structure of colloids for the manufacture of new materials and products.

No photography targets were uplinked to the crew last week for the Crew Earth Observations research program due to orbit changes caused by reboost activities to maintain the proper Station orbit. The next coordinates were scheduled to be uplinked to the crew on Thursday.

Other experiments continuing operations aboard the Station are: the Commercial Protein Crystal Growth experiment, the Active Rack Isolation System, and three radiation monitoring experiments -- Phantom Torso, Dosimetric Mapping and the Bonner Ball Neutron Detector.

The Payload Operations Center has sent more than 15,000 commands to the Space Station to date. The Expedition 3 cadre is scheduled to succeed the Expedition 2 team on round the clock operations on August 6. The Expedition 2 team is completing five months of round the clock operations and support for payload operations. In coming months, these controllers will be preparing to return to the control room for later Station missions.

In the meantime, controllers are continuing to update the software on board the Station to recognize the new payloads, and control software on the ground is undergoing similar updates.