NASA astronauts complete 2nd ISS spacewalk

NASA astronauts from the shuttle Atlantis have completed the second of three spacewalks outside the International Space Station (ISS).

Atlantis crew members Mike Foreman and Randy Bresnik successfully installed instruments outside the ISS during their excursion, which lasted six hours, eight minutes on Saturday.

Although the sortie was delayed for half an hour due to a false depressurization alarm, the pair managed to get ahead of schedule and do all tasks on the to-do list.

"Congratulations on another amazing day of work in space," mission specialist Megan McArthur told the astronauts from Mission Control in Houston, Texas.

Atlantis is on an 11-day mission to deliver spare parts including gyroscopes, ammonia tanks, and other heavy equipment in NASA's last mission to the ISS this year.

The third and final spacewalk is scheduled for Monday.

NASA plans to retire Atlantis and two sister ships-- Discovery and Endeavour--next year after five more missions to complete construction at the space station.

The Atlantis will depart the ISS on November 25 and arrive back in Florida on November 27.