SDL teams with Russian scientists to solve problems of growing plants in space

By Karen Wolfe and Jennifer Bowman
Utah State University Space Dynamics Laboratory
May 18, 2007

ISS Progress 25 cargo spacecraft launches from the Baikonur Cosmodrome in Kazakhstan.
Credit: NASA/Mark Bowman

North Logan—Early Tuesday morning, a cargo spacecraft carrying the world’s first space soil physics experiment docked with the International Space Station. The Optimization of Root Zone Substrates, or ORZS, is a collaborative venture between Utah State University’s Space Dynamics Laboratory and the Russian Institute of Biomedical Problems, or IBMP, that will help future space explorers overcome the challenges of growing plants in space.

“One of the difficulties experienced when growing plants in space is how to keep the roots from drowning,” said Shane Topham, lead electrical engineer with SDL.

On Earth, plants have the benefit of gravity to pull excess water away from a plant’s roots. But in space, just as astronauts hover in a microgravity environment, water hovers in the center of the container that holds the soil and the plant. Since roots grow toward water, plants growing in space often become deprived of oxygen, which eventually kills the plant.

“ORZS is the culmination of a 15-year collaborative effort involving USU/SDL and scientists from IBMP in Moscow,” said Scott Jones, USU assistant professor and experiment co-investigator. “It will be the first detailed ‘potting soil’ experiment to be performed on the ISS.”

Jones led USU’s effort to develop a soil substrate designed specifically for use in microgravity environments. SDL built the ORZS hardware that will hold the soil developed by USU. ORZS, which was funded by NASA and designed and built by USU students employed at SDL, contains nine soil chambers that measure oxygen diffusion through the soil at varying levels of water content.

Working together, USU/SDL and Russian scientists have been pioneers in the substrate and water content research that makes plants able to grow in space. “ORZS will test a range of soil particle sizes and moisture levels to see which will best transfer nutrient rich water and oxygen to the root system,” said Gail Bingham, chief scientist with SDL.

ORZS has great significance for NASA because many long duration space exploration scenarios, such as a Moon base or a trip to Mars, assume the capability of growing plants to provide food supplies for crew members.

“Both the American and Russian programs have a very big need for accurate plant root zone information,” explains Vladimir Sychev, head of IBMP’s Laboratory for Biological Life Support Systems. “We are looking forward to the successful ORZS experiment to provide this data. It will be an important step in our preparation for a flight to Mars.”

The Russian Space Agency launched the SDL-developed ORZS hardware and will support the on-orbit operations. Over the summer, Topham, and USU doctoral candidate Robert Heinse will monitor the experiment’s progress from the ground in Moscow.

While on orbit, the hardware will become part of the Lada plant growth chamber that SDL and IBMP have been flying in space since October 1992, first on MIR and then on the ISS.

To prepare the ORZS experiment for space flight, Topham and Jones tested the initial hardware four separate times on the “Vomit Comet,” the KC-135A that NASA uses to conduct zero-gravity tests.

ORZS and Lada are not SDL’s only cooperative research efforts with the Russian Federation. SDL has fostered their relationship with the Russians for nearly two decades. In 1997, a Russian presidential decree authorized the Russian Ministry of Defense to work collaboratively with SDL on space programs. This decree is still in effect and SDL retains a contractual arrangement for US/Russian cooperative efforts in space.