Storage on the International Space Station is just as important as on Earth. While the size of the ISS is comparable to the size of a football field, there is not much living space inside it. Just like you don’t store gardening tools in your home if you can put them outside in a shed, astronauts now have a “housing unit” in which they can store tools for use outside the space station. The new development was reported at NASA’s Goddard Space Flight Center.

On December 5, 2019, a protective repository for robotic instruments called the Robotic Tool Stowage (RiTS) was among the items launched into the station as part of SpaceX’s 19th commercial delivery mission for NASA. As part of the spacewalk on July 21, NASA astronauts Robert Behnken and Chris Cassidy set up a “robot hotel” where the instruments are stored in a mobile base station (MBS). MBS is a mobile platform that provides power to external robots. This location allows the RiTS storage facility to bypass the station along with a robot that will use the tools it stores.

Robots onboard ISS

RiTS provides thermal and physical protection for instruments stored outside the station, not only freeing up space onboard but also allowing the Canadian Space Agency’s Dextre robot to access them faster, said Mark Neumann, RiTS equipment manager.

The first step in the RiTS installation process involved preparing a block inside the space station. The astronauts unpacked the RiTS passengers from the vault – two blocks of an instrument called the Robotic External Leak Locator (RELL) – and attached them to the RiTS’s aluminum body.

RELL is a great example of how robots with the right tools can make life easier for astronauts. Dextre can use RELL to detect ammonia leaks, eliminating the need for astronauts to perform the same task during a spacewalk.

The ability to effectively detect and repair ammonia leaks is important because it is used to operate the plant’s cooling system.

Robots service

Installing RiTS makes the containment process much more streamlined. Prior to RiTS, RELL instruments were stored internally, and RELL deployments depended on the presence of an airlock and included waiting an additional 12 hours to allow the RELL gas analyzer to clear itself of internal gases. With RiTS, the only variable is Dextre availability, making it faster to find leaks.

After it was prepared at the station, the RiTS – loaded with two RELL squads – was sent out, along with the space astronauts who attached it to the MBS. During the spacewalk, this was the first task to modernize the systems of the International Space Station. The installation required the astronauts to mechanically plug the RiTS into an existing outlet at the worksite and then plug two electrical cables into the unused power outlets on the MBS. Plugging into the mains was critical to turning on the heaters in the RiTS that keep the RELL tools from getting too cold.

Although the station will use RiTS, human-robot collaboration such as this could potentially be applied to other endeavors involving humans in space.

RiTS was developed by NASA’s Research and Space Services Division of the Goddard Space Flight Center in Greenbelt, Maryland, in partnership with NASA’s Johnson Space Center in Houston.