In 2015, astronauts aboard the International Space Station ate the first produce ever grown in space. During Expedition 44, NASA astronauts Scott Kelly and Kjell Lindgren, as well as the Japan Aerospace Exploration Agency's Kimiya Yui, chomped down on red romaine lettuce that was grown in the station's Veggie plant growth system in August of that year.

It was a big moment, and a necessary step toward NASA's goal to travel to Mars someday. [Plants in Space: Photos by Gardening Astronauts]

As the new video from the agency's video series "Science at NASA"explains, the ability to grow both edible and nonedible plants in space is essential for deep-space travel and the establishment of dwellings. Plants provide both a food source and the ability to recycle air and water, Anna-Lisa Paul, a University of Florida professor who researches how plants grow in extreme environments, said in the video.