It is important for astronauts to be able to grow their own food in order to be healthy. The International Space Station has a number of experiments into growing crops, one of which uses no soil.

XROOTS hardware undergoing ground-based plant tests.
XROOTS hardware undergoing ground-based plant tests. Sierra Space

Growth media such as clay-like materials are used in other systems to allow plants to grow. The XROOTS system uses water based and air based methods instead of growth media. This is important because growth media can be difficult to maintain and could be unsanitary.

The XROOTS system was delivered to the International Space Station in February and integrated into the station's vege system. On Friday, June 24th, Jessica Watkins began the process of harvesting vegetables from XROOTS.

Our #XROOTS system using aeroponic/hydroponic techniques for plant microgravity research, is scheduled to launch today aboard a Northrop Grumman Antares rocket to the #ISS at 12:39 pm EST, from #NASA's Wallops Flight Facility in Wallops Island, Virginia.https://t.co/txhRhBV5CY pic.twitter.com/XUlEqpFNoI

— Sierra Space (@SierraSpaceCo) February 19, 2022

The XROOTS system is a technology demonstration and is intended to test out various options for growing plants without soil. Multiple chambers can be used at the same time to try out different options for air and water based systems. Researchers can use the hardware to take pictures and video of the plants as they grow and check their development.

The technology used to grow plants on Earth can be used in space, but there are challenges in adapting it. The problem of gravity is the main reason. Plants can grow strange in microgravity if lights are placed above them. The design of a system that can be used for all sorts of crops, including leafy green, fruiting plants like tomatoes, and root vegetables like carrots is one of the challenges.

The XROOTS system will be tested over the course of six months, using both sensor data and astronauts to see how plants grow.

There is a recommended video.