ISS Expedition Two Science Operations Weekly Science Status Report July 5, 2001

The Expedition Two crew continued to prepare the first plants and seeds
produced on the International Space Station for their return trip on the
Space Shuttle Atlantis set to visit the orbiting laboratory next week.

“The plants are the first to successfully go through three stages, seed
germination, plant growth and seed development aboard the Station,” said Dr.
Weijia Zhou, the principal investigator for the Advanced Astroculture
(ADVASC) plant growth experiment. Zhou is the director of the Wisconsin
Center for Space Automation and Robotics at the University of
Wisconsin-Madison — one of 17 NASA Commercial Space Centers that helps
companies fly space experiments. Eleven of these centers are managed by the
Space Product Development Program at NASA’s Marshall Space Flight Center in
Huntsville, Ala. – NASA’s lead center for flying experiments that take
advantage of low gravity.

“The Advanced Astroculture has provided optimal environmental conditions,
and the plants have entered their last stage of development — seed
maturity,” said Zhou. “This stage will last another few days, and then we
will change the conditions inside the plant growth unit to preserve the
seeds.”

To help the seeds dry out, Flight Engineer Jim Voss removed fluid from the
plant growth chamber this week. Periodically, during Expedition Two, the
crew has removed nutrients, fluids and gases so that investigators on Earth
could study the growing conditions experienced by the plants in space. When
the experiment is returned to Earth, scientists will analyze these samples
as well as the plants and seeds. Throughout the flight, investigators on the
ground have viewed video of the growing plants.

Zhou and his team at a telescience center at the University of
Wisconsin-Madison are working with the team at the Payload Operations Center
in Huntsville, Ala., on a plan for ending the experiment next week so that
the Space Shuttle Atlantis can return the plants and seeds to Earth. The
Advanced Astroculture was originally scheduled to return on the STS-105
Shuttle mission, but since the plants have finished their growth cycle, they
will be brought back on the STS-104 mission. The ADVASC science team is
running an identical experiment on the ground to determine how long the
experiment will require power before deactivation being planned for next
week.

The team at the Payload Operations Center is also planning for the return of
the Protein Crystal Growth Single Thermal Enclosure System Units 9 and 10 on
the STS-104 Shuttle mission. This experiment contains perishable biological
crystals that will be returned to scientists for analysis. By studying the
structure of the crystals, investigators can learn about substances that
play important roles in humans, animals and plants.

Most of the growth cylinders that contain crystals have been deactivated and
are ready for return to Earth. Next week, the crew is scheduled to
deactivate the last six growth cylinders in Unit 9, right after the STS-104
launch, now scheduled for July 12. Different biological substances require
different growth periods. Scheduled for return on STS-104 is the Commercial
Generic Bioprocessing Apparatus, which did not perform as expected and is
being returned for analysis.

The three radiation monitoring experiments – Bonner Ball Neutron Detector,
Phantom Torso, and Dosimetric Mapping – all continue to collect data. The
crew routinely uses the Human Research Facility computers to send data to
scientists on Earth for analysis. The Space Shuttle Atlantis will bring back
additional data on hard disks.

While a few experiments are being returned to Earth, several investigations
are just getting under way on board the laboratory and will continue into
Expedition Three, starting in August with the STS-105 mission. One of the
main goals of early science operations on the Station is to characterize the
laboratory environment so that scientists can accurately analyze the
influence it has on their experiments.

In addition to measuring the radiation inside the lab, scientists are
measuring the effects of vibrations and evaluating ways to reduce them. Next
week when the Shuttle docks with the Station is a critical time for these
measurements because more vibrations may be experienced when the Shuttle
docks and during the increased activities while it is docked.

The Microgravity Acceleration Measurement System was reactivated last week
and will be on for the next four weeks to help characterize the microgravity
environment of the Station. The other microgravity measurement device, the
Space Acceleration Measurement System, continues to actively record data.

An experiment that could make the Space Station an even better place to
conduct microgravity experiments continues to under go tests this week and
prepare for more specific tests during docked operations next week. The
Active Rack Isolation System (ARIS) located in EXPRESS Rack 2 in the Destiny
lab module is designed to act like a powered shock absorber to dampen
vibrations from powered equipment and crew activities.

During the past week, the Payload Rack Officer at the Marshall operations
center and the science team on the ground prepared the rack system for
special tests during docked operations. While the Shuttle is docked, the
ARIS ISS Characterization Experiment (ARIS-ICE) will precisely test and
measure the performance of the ARIS vibration dampening system.

“We’re continuing checkout tests to get ready for the Space Shuttle docking,
which adds greater mass to the Station and will allow us to do low-frequency
testing,” said James Allen, ARIS-ICE project lead and payload developer,
with The Boeing Company in Houston, Texas.

Other payloads continuing to operate nominally include: Commercial Protein
Crystal Growth and the Experiment on the Physics of Colloids in Space. The
crew is also completing weekly questionnaires as part of the Interactions
experiment.

Editor’s Note: The Payload Operations Center at NASA’s Marshall Space Flight
Center in Huntsville, Ala., manages all science research experiment
operations aboard the International Space Station. The center is also home
for coordination of the mission-planning work of a variety of international
sources, all science payload deliveries and retrieval, and payload training
and payload safety programs for the Station crew and all ground personnel.