NASA astronauts aboard the are planning to eat vegetables grown in outer space for the first time ever aboard the International Space Station Monday. The milestone, which involves eating space-grown lettuce, is another step forward for the agency's plan to ultimately send a manned mission to Mars.

It's all part of Veg-01, NASA's experiment to see how effectively gardens on the ISS will feed space crews over the course of long duration missions. Astronauts will need to clear the “outredgerous” romaine lettuce with food-safe citric acid sanitzing wipes before eating, NASA announced in a statement. Any leftovers will be sealed and packaged so they can be tested on Earth.

“There is evidence that supports fresh foods, such as tomatoes, blueberries and red lettuce are a good source of antioxidants,” Dr. Ray Wheeler, lead for Advanced Life Support activities in Exploration Research at Kennedy Space Center, said in a NASA Statement. “Having fresh food like these available in space could have a positive impact on people's moods and also could provide some protection against radiation in space.”

After sitting onboard the ISS for 15 months the seeds in the Veg-01 crop were activated on July 8 and grown for 33 days. If all goes according to plan, NASA said, the space agency could utilize the Veg-01 method to increase “growth and biomass production on Earth.”