NASA selected radishes because they are well understood by scientists
NASA astronaut Kate Rubins harvested radish plants growing in the Advanced Plant Habitat (APH) aboard the International Space Station. She meticulously collected and wrapped in foil each of the 20 radish plants, placing them in cold storage for the return trip to Earth in 2021 on SpaceX’s 22nd commercial Resupply Services mission.
The plant experiment, called Plant Habitat-01 (PH-02), is the first time NASA has grown radishes on the orbiting laboratory. NASA selected radishes because they are well understood by scientists and reach maturity in just 27 days. These model plants are also nutritious and edible and are genetically similar to Arabidopsis, a small flowering plant related to cabbage that researchers frequently study in microgravity.
The structure of the experiment will allow NASA to identify the optimum balance of care and feeding needed to produce quality plants. While growing inside the habitat, the radishes required little maintenance from the crew.
The chamber also uses red, blue, green, and broad-spectrum white LED lights to provide a variety of light to stimulate plant growth. Sophisticated control systems deliver water, while control cameras and more than 180 sensors in the chamber allow researchers at NASA’s Kennedy Space Center to monitor the plant growth as well as regulate moisture levels, temperature, and carbon dioxide (CO2) concentration.
The team has set up a control population of plants in the ground control plant habitat unit in the International Space Station Environmental Simulator (ISSES) chamber inside Kennedy’s Space Station Processing Facility. Radishes have been growing under nearly identical conditions in the ISSES since Nov. 17.
