spacetoday.net: NASA plans two spacewalks to fix ISS cooling system

Posted: Tue, Aug 3, 2010, 9:46 AM ET (1346 GMT)
ISS illustration (NASA)

NASA is proceeding with plans to perform two spacewalks starting late this week to repair a cooling system that malfunctioned over the weekend. ISS astronauts Douglas Wheelock and Tracy Caldwell Dyson will perform two EVAs, one Friday morning and the other the following Monday, to remove a faulty ammonia pump and replace it with a spare unit. The pump shut down Saturday night, forcing station controllers to shut down a number of systems on the station to reduce the station's electrical load and thus the amount of heat it generates. The pump unit will be replaced on the first spacewalk, with the second used to make electrical and coolant line connections to the new pump unit. The two EVAs replace one already scheduled for late this week to perform routine maintenance on the station.