Had enough of home-grown vegetables? How about extraterrestrial greens? North Carolina State University (NCSU) researchers are trying to create programmable space plants that one day could help sustain a human settlement on the moon or Mars.
The scientists hope to create plants containing tiny biochip control devices in their cells capable of receiving and transmitting signals to a station millions of miles away on Earth. On command, these Martian wheat stalks or lunar potatoes would be able to undergo genetic modification. They could produce more or less oxygen depending on the needs of human space settlers, prepare for cold weather by hardening their stems, or adapt to lower levels of light by elongating. The plants would probably be grown in special greenhouses that would help them survive Martian temperatures that dip as low as minus 175 degrees (minus 115 centigrade), and gravity that's only 38% as strong as Earth's.
The veggies would transmit such data as the level of nutrients and water in their diets back to the control center, explains Chris Brown, director of space programs at NCSU's Kenan Institute for Engineering, Technology & Science and the main force behind the project. Scientists on Earth would detect any plant distress before visible signs, such as wilting, became apparent.
Eventually, the researchers hope to figure out how to grow organic sensors that are part of the plant itself. "What we need to do is tap into the vast resources of the plants' own genetics," says Brown. He plans to focus his research on wheat, soybeans, and potatoes. He aims to start demonstrating the feasibility of the project by working on a small, genome-sequenced weed called arabidopsis.
Programmable plants are not as pie-in-the-sky as you think. "Applications on Earth are immense," Brown says. A farmer, for instance, would be able to check on the wellbeing of crops in corn fields miles away without leaving home, before any signs of distress become apparent. If a cold front were forecast to move into the area, the farmers could order their crops to get ready.
A fair amount of research has already been done on in this area. Scientists at NCSU and other universities have built some types of sensors, measuring pH and potassium levels, into the stems of plants. NASA already has a prototype Martian greenhouse -- though it's only one meter in diameter. And researchers have seriously looked into using plants, which can produce oxygen, food, and fiber, and purify water, for advanced life support in space since the 1980s, says NASA plant physiologist Ray Wheeler.
The plants could be crucial to prolonged space travel: No vessel can possibly carry enough food for astronauts to survive months and years away from Earth, says Nina Stromgren Allen, NCSU professor of botany and Brown's team member. The trip to Mars could take about nine months, and the astronauts would need to wait some 18 months more for the right juxtaposition between Mars and Earth before making their nine-month journey back. Plants would be ideal for helping sustain humans over such long periods because they take energy from the sun and are self-perpetuating, so there's no need for resupply. And scientists hope to make the programmable control genes in the plants inheritable, says Brown.
Once humans decide to journey to Mars, seeds, a planting robot, and a special -- possibly inflatable -- greenhouse could be sent up in advance. The plants' genetic structure could be optimized to adapt to the local conditions. By the time the tired travelers arrived on the Red Planet, they could have a harvest waiting for them. The plants could provide the air, water, food, fiber, and other materials needed to sustain human existence beyond Earth. At present, a physico-chemical life-support system can provide clean air and water but can't produce food.
Much work has to be done before potatoes and soybeans blast off into space, however. Brown has just completed the first feasibility study, funded by a $75,000, six-month grant from NASA's Institute for Advanced Concepts. But his six-member team hopes to get a two-year, $500,000 grant from NIAC next fall to do advanced scientific and economic feasibility studies of programmable plants, Brown says. If all goes well, the pioneering greens could become a reality in 10 to 20 years, says Robert Cassanova, NIAC's director.
How soon NASA might commission a mission requiring life support from plants is up in the air. "There's nothing on the books in the next five years," says Wheeler. "It all depends on the political winds." But if an ambitious space mission is ever launched, it's certain no fast-food outlets will be waiting for the explorers when they arrive. Brown and other researchers hope to fill the gap.
By Olga Kharif in New York
Edited by Thane Peterson