ISS Research Results: Advanced Astroculture (ADVASC)

Results

Expedition
4 Flight Engineer Carl Walz collected the final plant and gas samples during
the week of April 1, 2002, before the ADVASC-GC-02 unit was deactivated
on Sunday, April 7. The growth chamber will be returned on the Shuttle Atlantis
(STS-110), which docked with the Station on April 10. The support system
will remain on the Station in anticipation of the arrival of ADVASC-GC-03
during mission UF2 later this year. Activated
on February 12, ADVASC-GC-02 had seedlings growing in it by early March.
The growth chamber contains Arabidopsis seeds produced during ADVASC’s
first flight (ADVASC-GC-01). "This will be second-generation Arabidopsis
plants produced from the seeds produced by those first-generation space-grown
plants," described Dr. Weijia Zhou, principal investigator for ADVASC
and director of the Wisconsin Center for Space Automation and Robotics
(WCSAR) at the University of Wisconsin, Madison. "Additionally, we
are going to sample the plant tissue and preserve it for RNA and DNA analysis
after returning to the ground. Hopefully it will provide important information
regarding the impact of low gravity on the plant gene expression."

ADVASC-GC-01,
activated on May 10, 2001, was the first experiment on Station to return
data to ground centers via video. By the week of May 28, the seeds had
sprouted. The research team reported that the seedlings appeared on the
video to be slightly larger than expected. The plants began to flower
during the week of June 11 and had produced seeds within two weeks. During
the first week of July, Increment 2 Flight Engineer Jim Voss had raised
the heat and removed nutrients, fluids, and gases from ADVASC unit in
order to dry out the plants and preserve them for their return to Earth.

The
unit, plants, and samples were returned to Earth by STS-104 on July 24,
and sent to WCSAR. Approximately 90 percent of the seeds sent into space
germinated. Of those, about 70 percent grew siliques (elongated, two-sided
seed capsules characteristic of the mustard family), with an average of
24 siliques containing 36 seeds per plant. WCSAR researchers are also
comparing the space-grown plants to a control group grown under similar
conditions on the ground. Part of the analysis also includes determining
cell wall and chemical composition. Differences between the ADVASC plants
and the ground-control plants will likely be due to the microgravity environment.
The overall health and vigor of the space-grown plants will tell researchers
whether the growing conditions—temperature, moisture, and fertilizer concentrations—were
optimal. Some of the seeds are currently being grown in ADVASC-GC-02,
but most of the seeds were turned over to Space Explorers, Inc., for use
in their educational kits and other commercial endeavors.

Applications

Long-term plant research may allow crews on long-duration
space flights to successfully grow and nourish their own crops. Plants
also provide a natural air and water filtration system. From the humble
beginnings represented by ADVASC may come advanced, large-scale plant
growth systems for spacecraft. Space horticulture is the cornerstone of
a healthy, enclosed life support system for future human space exploration.
Furthermore, plant growth systems provide a little piece of Earth that
helps make the spacecraft environment feel more like home.

Finding
the key to growing crops in space – a challenging
growing environment—may also improve crop yields on Earth by helping scientists
to genetically tailor plants that will withstand disease and inhospitable
conditions, and will require less growing space.

Components
of the ADVASC system have yielded some surprising benefits. Homeland defense
has been on the minds of many Americans since September 11, but few would
have expected that a safety device would come from a plant growth chamber
orbiting Earth. Ethylene is a natural byproduct of growing plants, but
too much of this gas can build up in a growth chamber, causing plants
to mature before they have had a chance to properly produce fruit and
seeds. Researchers at WCSAR invented Bio-KES, a device that uses ultraviolet
lights to convert ethylene into carbon dioxide and water, to remove ethylene
from growth chambers like ADVASC. Scientists at the University of Wisconsin
discovered by increasing the intensity of the ultraviolet lighting, they
could use Bio-KES technology to kill pathogens like anthrax. The air scrubber,
named AiroCide TiO2, is now being manufactured by KES Science & Technology,
Inc., of Kennesaw, GA. For more on this space research spin-off, please
visit the NASA
News Release.

Researchers
have also found that the light used for photosynthesis in ADVASC heals
wounds and improves the effectiveness of cancer-fighting drugs. 
The light-emitting diodes (LEDs) developed for WCSAR by Quantum Devices,
Inc., have been successfully used in surgical devices that remove tumors.
Cooler than a laser, these LEDs can target diseased tissue without harming
the surrounding healthy tissue.

Additionally,
ADVASC provides an active link between science conducted onboard the ISS
and the education community.  Space Explorers, Inc., commercial partner
on the ADVASC experiment, has developed Orbital
Laboratory, an Internet-based, multimedia educational tool that allows
students (grades K-12) to conduct experiments on the ISS and to analyze
returned data.  Students will be able to access ADVASC plant
data and discuss data gathered by other participating schools worldwide.
Space Explorers, Inc., and InnerLink, Inc., have developed the Orbital
Laboratory Payload 002 Innerlinkit,
a commercially available kit that contains supplies necessary to participate
in the ADVASC experiment and a one-year subscription to the Orbital Laboratory
Web site.

Related Publications

Web Sites