US astronauts step out on spacewalk

Spacewalk is the 190th in support of International Space Station, marking 15 continuous years of human habitation

MIAMI: Two US astronauts stepped out on a spacewalk on Friday to complete the repair of an ammonia cooling system at the International Space Station.

Scott Kelly and Kjell Lindgren switched their spacesuits to battery power at 6:22 am (1122 GMT) and floated outside the orbiting outpost moments later, according to a live broadcast on NASA television.

Their goal for the 6.5 hour spacewalk is to "restore the port truss ammonia cooling system to its original configuration following a leak detection exercise three years ago that ultimately resulted in the replacement of an ammonia pump on the station's truss," NASA said in a statement.

The spacewalk is the 190th in support of the International Space Station, which just marked 15 continuous years of human habitation.