NASA spacewalkers Peggy Whitson and Jack Fischer replaced a faulty computer relay box on the International Space Station today, but not before dealing with a problem all too familiar to home fixer-uppers.
The box, about the size of a microwave oven, is known as a multiplexer-demultiplexer or MDM. It’s one of two MDMs that regulate the operation of the station’s radiators, solar arrays and cooling loops. The component failed on May 20, but because each box can handle all essential functions, operations on the station weren’t affected.
NASA decided to go ahead with a rapid-response spacewalk today to preserve the system’s redundancy, and Whitson made quick work of uninstalling the failed equipment. However, when it came time to install the replacement, she found she couldn’t secure the primary bolt that was supposed to hold it in place.