|Officials stressed that the six occupants of the International Space Station were in no danger after the shutdown, and that the orbiting complex was in a stable situation.|
After huddling Sunday, NASA managers gave preliminary approval for a pair of spacewalks, the first of which would take place later this week. Two of the Americans on board were already scheduled to conduct a spacewalk Thursday for routine maintenance, though the repairs would supersede the original chores.
Officials stressed that the six occupants were in no danger, and that the orbiting complex was in a stable situation.
The trouble arose Saturday night, when one of the two ammonia-fed cooling loops shut down. Alarms sounded throughout the sprawling outpost as the circuit breaker for the pump in that line tripped, causing the pump to stop working.
The cooling system is critical for on-board operations. The two ammonia lines ensure that all the station’s electronic equipment does not overheat and with one of those out of commission, there is no safeguard in case of a second failure.
Astronaut Tracy Caldwell Dyson hustled through the equipment shutdown procedures and, with crewmate Douglas Wheelock, installed a jumper cable to keep all the rooms cool.