Spacewalks (EVA) may be needed to fix ISS cooling device: NASA

Astronauts aboard the International Space Station may need to undertake unscheduled spacewalks later this week after one of the orbiting outpost's ammonia cooling systems broke down, NASA said Sunday.

Officials at the US space agency's mission control in Houston, Texas, "are discussing options to perform two spacewalks later this week to replace the pump module," said NASA.

An attempt to restart the ammonia-fed cooling loops on the ISS prompted the pump module's circuit breaker to trip early Sunday for a second time after it failed Saturday night and was reset.