GREENBELT, Md. (NASA PR) — On April 8, the Robotic Refueling Mission 3 (RRM3) aboard the International Space Station started experiencing issues powering up its cryogen coolers that maintain the temperature of liquid methane contained within the module. After several troubleshooting attempts, it was determined the coolers could not be powered up. As a result, the temperature of the liquid began to rise. The liquid methane turned into a gas and was safely vented from the payload. There was no impact to other station systems or operations.
While RRM3 can no longer perform a cryogenic fuel transfer, its four months on station taught NASA about the technology needed to store and transfer cryogenic fuel in space. The mission will carry out other planned operations with servicing and inspection tools. Ultimately, RRM3 will still help bring NASA closer to replenishing cryogenic fuel in space so spacecraft can live longer and journey farther into the solar system.
RRM3 launched to the space station in December 2018 and is installed to the outside of station on Express Logistics Carrier-1.