Astronauts flying to Mars or beyond may be able to grow their own veggies during the long trip using new technology tested in the Arizona desert.

During a two-week trial, NASA put a compact vegetable-growing unit through its paces as part of the agency's annual Research and Technology Studies demonstration, also known as Desert RATS. The unit, developed by the Wisconsin-based company Orbitec, grows salad-type crops using a minimum of space and energy.

"We're very excited about it," said Paul Zamprelli, business director for Orbitec. "It's another piece of the puzzle for long-duration missions, and for habitat missions on the moon and Mars." [Top Space Foods of All Time]

Building on existing technology

The new Orbitec unit, which the company calls "Veggie," contains LED lighting and a matting that delivers water and nutrients to a plant's roots. Each Veggie unit provides up to one square meter (about 10.8 square feet) of extremely productive growing area, according to the company.

"By controlling lighting and humidity, we maximize plant growth and can turn over crops very quickly," Zamprelli told SPACE.com.

The Veggie unit is based on one of Orbitec's previous systems, which got a field test on the International Space Station several years back. But the new set-up has a different lighting system that is more efficient and uses less power, the company says.

And unlike the older system, Veggie isn't totally enclosed, meaning crops would be more accessible to a spacecraft's crew.

"We think of it as like a garden," Zamprelli said. "Astronauts can go in and pick the vegetables."

During Desert RATS, which wrapped up Wednesday (Sept. 15) north of Flagstaff, Ariz., NASA-led teams of scientists and engineers tested out prototype hardware for future space missions.

The program only runs for two weeks each year, not enough time to grow any leafy greens in a prototype spacecraft or habitat. So Veggie's Desert RATS run was more of a show-and-tell demo than a proper field trial. But Veggie should get that chance soon, according to Zamprelli.

"We fully expect that two Veggie units will get the go-ahead to go up to the space station soon," he said.

The need for space greenhouses down the road

The Veggie system fits in well with NASA's priorities. In addition to researching ways to grow crops on other worlds, the space agency has been conducting plant-growth experiments in space for years.

"We pretty much always have some plants growing on the space station," said Julie Robinson, NASA program scientist for the International Space Station.

Most of these experiments have focused on plant roots, she said, to figure out how microgravity affects crops' water and nutrient uptake. Some of the research has delivered surprises. Overwatering lettuce in space, for example, didn't harm the plants; it caused them to sprout and grow twice as fast.

NASA has other space-crop research angles, too. The agency is investigating algae-powered bioreactors, to see if such devices could generate enough oxygen for astronauts to breathe. Finally, NASA wants to know if astronauts on a long space flight could grow enough food to sustain themselves, and if these space crops would be healthy and good to eat.

Robinson said this last goal — the one that Veggie is directly addressing — is more of a long-term objective, one that needs to be dealt with if we want to travel beyond Mars.

"You'd have to be going farther than Mars to really need to grow food," she told SPACE.com. "The lack of fresh fruit and vegetables wouldn't be a huge deal. People can survive on rations for six months if they need to."