Houston, TX, United States (4E) – Two astronauts completed the first of three spacewalks to fix a broken ammonia pump outside the International Space Station on Saturday with the follow-up spacewalk to be done on Tuesday.
Flight Engineers Rick Mastracchio and Mike Hopkins took five hours and 28 minutes to remove an ammonia pump in the ISS part called Loop A. A valve inside the pump got stuck and caused temperatures in the ISS’s cooling line to drop on Dec. 11. Some equipment at the ISS were shut down as a contingency.
The spacewalk at 12:29 p.m. EST Saturday was broadcast on NASA Television. Hopkins made his way out to the worksite at center of the Starboard 1 truss segment while Mastracchio attached himself to a foot restraint at the end of the station’s 57-foot robotic arm, which Flight Engineer Koichi Wakata positioned to the worksite.
Hopkins and Mastracchio disconnected four ammonia fluid line from the pump module, attached them to a pump module jumper box and installed thermal cover on the box and lines. The pump module jumper box routes ammonia to the ammonia and nitrogen tanks to keep it in a liquid state.
The two astronauts then removed the 780-pound degraded pump module from the starboard truss and attached it to a stowage location on the Payload Orbital Replacement Unit Accommodation on the orbiting station’s railcar, or Mobile Base System.
The next spacewalk is scheduled at 6:15 a.m. EST on Tuesday and involves the replacement of the degraded pump module. The task was supposed to be done Monday but delayed because a backup spacesuit that Mastracchio had to use needed to be resized to fit him.
The flight control team at NASA’s Johnson Space Center in Houston have directed Mastracchio to use the spare suit because his encountered an issue when he stepped into the ISS’s airlock after the spacewalk.