Astronauts grow radishes in the second advanced plant habitat experiment in space

Plant Habitat-02 (PH-02) photographed November 11, 2020 by NASA astronaut Kate Rubins aboard the ISS. Credit: NASA / Kate Rubins

Earlier this month, NASA astronaut Kate Rubins photographs the first major milestone of the Plant Habitat-02 (PH-02) experiment aboard the International Space Station. The survey studies the growth of radishes in a microgravity environment. NASA chose radish because it is a model plant: both nutritious and edible, with a short growing time and being genetically similar to Arabidopsis, a plant frequently studied in microgravity.

Growing within her Advanced Plant Habitat for 27 days, the plants require little maintenance from the crew. The grow chamber contains LED lights, a porous clay material and a controlled fertilizer release system to deliver water, nutrients and oxygen to the plant’s roots. The cameras and more than 180 sensors in the chamber allow researchers at NASA’s Kennedy Space Center in Florida to monitor plant growth and regulate conditions such as water distribution, humidity levels and temperature.

As we prepare to send humans back to the moon and up Mars, the need for astronauts to grow fresh food in space is greater than ever. Plant Habitat-02, or PH-02, is an experiment launched on Northrop Grumman’s 14th refueling mission to the International Space Station. Credit: NASA’s Kennedy Space Center

The crew aboard the orbiting lab is expected to harvest the radishes later this month. The samples will then be returned to Earth for researchers to better examine how well the radishes have grown.

With plans to explore the Moon and one day Mars, NASA is gaining a better understanding of how to grow fresh produce in space for the crew on long-duration missions further from home. As part of the Artemis program, NASA plans to establish sustainable exploration on and around the Moon by the end of the decade and will be able to send supplies to the crew from Earth. Future astronauts headed to Mars will travel for about two years before returning to Earth and will have to carry all the supplies they will need for the duration of the mission. Learning how to grow food closest to home aboard the space station will help determine which plants thrive best in microgravity conditions and offer the best variety and nutritional balance for a Martian menu.