Discovery astronauts complete ‘textbook’ spacewalk

WASHINGTON - Two space shuttle Discovery astronauts moved a failed ammonia cooling pump during a more than six-hour spacewalk outside the International Space Station.

NASA officials called Monday’s work a “textbook” spacewalk, after overcoming a problem with the station’s robotic arm that left astronaut Steve Bowen holding the weightless pump for a bit longer than expected.

It was the first of two spacewalks in the shuttle mission,

which is Discovery’s last before the spacecraft is retired.

NASA said after the spacewalk that it had decided to add another day to the mission, making it a 12-day affair, in order to allow Discovery astronauts to help with work setting up a new room that it carried aloft.

Astronauts Bowen and Alvin Drew also installed a back-up power extension cable and camera equipment and did other work to make future spacewalks easier.

Before heading back inside, they filled a metal container with the vacuum of space as part of a Japanese experiment called “Message in a Bottle” that will later be displayed on Earth.

The cooling pump broke last year and had to be relocated from a temporary storage location where it had been stashed on an earlier spacewalk. It had to be moved before it can be taken back to Earth for analysis.

The six-hour, 34-minute spacewalk wrapped up at 2220 GMT.

A second spacewalk is set for Wednesday.

Two more shuttle flights are planned for later this year in the final missions for the rest of the fleet, Endeavour and Atlantis.

Discovery’s mission is delivering the last major US contribution to the ISS - an extra room - along with supplies and equipment, including a human-like robot, known as Robonaut 2 (R2), the first such robot ever sent to space.