During long trips in space, the variety of foods will be the key.
A new NASA experience called Veg-PONDS 02, which astronauts have just piloted on the International Space Station, offers a chance to reach this diversity. Although the experiment used a food already grown in space, romaine lettuce, future crops could include tomatoes or other plants, NASA officials said in a statement.
Previous experiments on food on the International Space Station used sacks of seeds (also called pillows) that received water from syringes that astronauts introduced into the bags. Although this water is sufficient to allow lettuce to grow, tomatoes and similar crops use more water. NASA has therefore launched a 21-day test, which ended May 16 – which could eventually give astronauts at the space station more fresh food to eat.
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The new method allows astronauts to cultivate romaine lettuce seeds in 12 passive orbital nutrient delivery systems (PONDS). PONDS units are cheaper than seed bags and can hold more water, while leaving more room for root growth. Another advantage of PONDS is that they use less energy, which means that electricity can be used for other objects on the space station. Six of the 12 PONDS units will be returned to Earth for a future SpaceX mission for further analysis. Later, the design of PONDS will be finalized to test how to grow crops other than romaine lettuce, NASA officials said in a statement.
More nutritional variety will be needed for space travelers on their way to Mars or other distant destinations. As the space station orbits the Earth, astronauts heading for space will have to carry more of their equipment with them because it is not cost-effective or quick to replenish crews in a remote location.
"There comes a time when you have longer and longer missions and you reach a cost-benefit point where it makes sense to grow your own food," Howard Levine, Chief Scientist of the Office of Life Sciences and NASA's use at the Kennedy Space Center, said in the statement.
The participating researchers came from NASA, Techshot, Tupperware Brands and Portland State University.