Mustard Plants to Boldly Grow Where… On board the space shuttle that lifted off July 4 was a black plastic briefcase marked "Critical." Inside were 600 seeds that scientist John Kiss hopes will help scientists figure out which crops grow well in space.
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Mustard Plants to Boldly Grow Where…

Researchers plan to study how mustard plants, like the one shown here, responded to light and gravity inside the International Space Station. Vo Trung Dung/Corbis Sygma hide caption

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Vo Trung Dung/Corbis Sygma

On board the space shuttle that lifted off July 4 was a black plastic briefcase marked "Critical Space Item." Inside were 600 seeds.

John Kiss watched from the ground as the briefcase holding his experiment zoomed into space. The seeds are currently orbiting the Earth at 17,500 miles per hour on the International Space Station. Kiss is back in Ohio.

Over the next three months, the lowly mustard seeds will sprout and grow far away from their home turf. Sending seeds into space may seem a little drastic, but Kiss is a professor of botany at the Miami University of Ohio, and in his regular lab, he can't remove gravity.

Kiss wants to know how a plant perceives light and grows toward or, in some cases, away from a light source, like when your houseplants turn toward the window to capture light filtering through the glass. Gravity complicates his experiments because plants respond to gravity as well as to light. This means, for example, that on Earth, researchers can't tell why a root grows downward: Is it being drawn toward gravity or is it repelled by light? To complicate matters further, roots respond in different ways to different colors in the light spectrum. Roots grow away from blue light, but toward red light.

To try to untangle this mess, Kiss planned an experiment to grow plants under controlled conditions — with red light or blue light and with different levels of gravity, from almost no gravity to the amount of gravity we feel on Earth. The only place where he can dramatically reduce gravity is on board the International Space Station.

Although Kiss will not be on board to monitor his experiment, a video camera will tape the plants' growth. The plan is that the astronauts on board the International Space Station will ultimately harvest the plants and freeze them. The third space shuttle of this year will bring them back to Earth along with home movies of the plants' lives from birth to harvest.

The videos will make it possible for someone in the lab to measure how much the roots and shoots curved toward the light source. Kiss will also grind up the harvested plants and analyze their DNA. He hopes to learn how particular genes behaved as the plants responded to light and gravity.

NASA chose this experiment for the space station because they hope this sort of research will enable scientists to bioengineer plants with the particular genes that allow them to grow well in the space. NASA hopes astronauts can grow plants as crops and as oxygen producers during future missions to the moon, and as Kiss hopes, to Mars.