Space Farming? NASA Crew Plants Lettuce on the International Space Station

Astronauts in the International Space Station (ISS) are starting to plant their third on-orbit lettuce.

NASA astronaut Shane Kimbrough, a new crew member aboard the ISS, started the Veg-03 experiment, which is a validation of the tools and procedures needed to grow plants to provide fresh food for astronauts, NASA said in a statement. Kimbrough started installing hardware and plant pillows for the experiment, while the other members of the Veggie team watched from their consoles in the Experiment Monitoring Area in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida.

"Operations went great today! A little slower than expected, but all plant pillows were successfully primed for the first time in our Veg series," Nicole Dufour, NASA's Veggie project manager, said in a NASA news release.

"We previously have had some hardware issues that prevented at least one pillow from each 'grow out' from being successfully primed, so we were very excited to achieve that milestone."

Plant pillows are small pouches that contain growth medium, fertilizer, and seeds. To grow the crops, astronauts simply have to add a small amount of water into them.

The ISS has a Veggie plant growth facility where previous experiments had been conducted. Veg-03 builds on the success of previous experiments, such as the Veg-01, which resulted in the first-ever on-orbit harvest and sampling of fresh produce during the summer of 2015, NASA said. The Veg-03 crop will be the Veggie team's first in-orbit attempt at a new and repetitive harvest technique called "Cut-and-Come-Again."

"Once the plants are approximately four weeks old, a selection of leaves can be harvested for a bit of fresh lettuce and possibly science samples. Meanwhile, some leaves are left intact along with the core of the plant, and will continue to grow and produce more leaves," Dufour said.

"We expect this will increase the on-orbit crop yield, as well as allow for more opportunities to supplement our astronauts' diets with fresh, nutritious food from the same plants, which is an important goal of the 'pick-and-eat' food concept."

According to NASA, space farming is not just for the ISS crew. The agency also considers employing the same method during future long-term missions, such as NASA's Journey to Mars.