NASA To Study Plants To Help Astronauts Grow Food In Space

Ruth Marlaire June 27, 2006
NASA Ames Research Center, Moffett Field, Calif.
Phone: 650-604-4709 or 604-9000
e-mail:

RELEASE: 06-45AR

NASA TO STUDY PLANTS TO HELP ASTRONAUTS GROW FOOD IN SPACE

Someday, astronauts may grow food efficiently in space and use plants
to clean spaceship air, thanks to a two-year experiment scheduled
aboard the International Space Station.

The next space shuttle mission, STS-121, will carry the Tropi
experiment's apparatus into space when the shuttle hurtles into orbit
after its July 1 scheduled launch. Scientists will study a weed in
the cabbage and mustard family, to see if its roots grow more readily
toward red or blue light, according to scientists.

"Arabidopsis thaliana is a common weed, which we've found in our
parking lots," said Mike Eodice, the experiment's project manager at
NASA Ames Research Center, located in California's Silicon Valley.
"NASA has selected this plant as a model specimen for space research
since the plant's genetic structure has been fully mapped. The plant
is also a good research specimen because it is very hearty," Eodice
explained.

Researchers will use a small video camera to observe the roots while
they grow inside seed cassettes. The cassettes will be housed within
a special plant research facility, called the European Modular
Cultivation System (EMCS), developed by the European Space Agency.

For three days, the dry seeds will be given water and light, which
will allow them to grow to a size of about 1.2 inches (3
centimeters). At that point, the plants are large enough to begin the
experiment.

"Plants have several mechanisms to perceive and respond to light
stimuli. Their ability to sense specific wavelengths (color) of light
is why we are studying both the blue- and red-light-sensing system in
the Tropi experiment," said Dr. John Kiss, project principal
investigator at Miami University, Oxford, Ohio. "These issues are
important for the use of plants to support life on long-term space
missions such as spaceflights to Mars," Kiss said.

Researchers also will study how combinations of gravity levels and
light affect plant growth. To create different levels of artificial
gravity, researchers will spin plants at various speeds on a
centrifuge.

The mustard plant experiment is the third part of a comprehensive
study of how crop yields could be increased for missions that could
last many months or even years. Plants that will be used for food may
well be used to filter spaceship air and produce oxygen.

Scientists discovered in previous missions that spaceship parts emit
ethylene gas, the same emission that creates the new car smell that
consumers notice in automobiles and other new products. Earlier
experiments also showed that exposure to the gas produced less starch
in the roots of the affected mustard-family plants, and reduced their
growth.

"In space, materials off-gas (new car smell) and these emissions can
be harmful to plants. We design hardware to eliminate these toxic
gasses," said Eodice.

To eliminate emissions of ethylene and other toxic gases, a team of
NASA Ames engineers designed and manufactured the most highly
sophisticated plant hardware ever built for a space shuttle mission,
called the Tropi Experiment Unique Equipment. Engineers designed this
machine to prevent the build-up of toxic gases harmful to plants.
Ethylene removal is accomplished by special equipment inside the EMCS
facility.

After astronauts return the space-grown plant samples from the
experiment to Earth, scientists will examine the plants' genes to
learn how the space environment has affected plant growth.

According to scientists, further understanding of how plants grow and
develop at a molecular level can lead to significant advancements in
agricultural production on Earth.

"A better understanding of the role light and gravity play in plant
growth has the potential to improve crop yield in arid regions that
have fewer resources to support plant life, such as space, water,
light, air, or soil," concluded Eodice.

For more information about the Tropi experiment on the Web, visit:

http://exploration.nasa.gov/programs/station/Tropi.html


For more information about NASA and agency programs on the Web, visit:

http://www.nasa.gov/home


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