Astronauts to make repairs during second spacewalk

A day after receiving the good news that it would be safe for the space shuttle Discovery to return to Earth, astronauts awoke today to begin their latest task: taking the second of three planned spacewalks to make repairs to the international space station.

The plans for today’s spacewalk lacked the drama of the astronauts’ jaunt on Saturday, when they stood on the end of a sometimes-oscillating 100ft shuttle robotic arm connected to an extension boom. They were testing its sturdiness for making repairs to the space shuttle.

Their more mundane tasks this time involved installing a spare external pump compartment to the station’s cooling system and replacing a severed cable that provides power, video and data to the space station’s rail car.

The spacewalk, arriving at the middle of space shuttle Discovery’s 13-day mission, was expected to last under seven hours.

Replacing the cable on the rail car, or mobile transporter, is crucial for the continuation of construction of the space station. The cable was accidentally severed last December by a cable cutter. During Saturday’s spacewalk, the astronauts immobilised a cable cutter on a duplicate cable leading to the transporter.

In what may be an awkward manoeuvre, astronaut Piers Sellers will hold the old cable reel – which weighs 330 pounds on the ground – in one hand and the new one in the other.

“The most challenging thing is going to be just the choreography, going back and forth in the payload bay,” said astronaut Mike Fossum said. “It’s quite a ballet.”

Discovery’s four other astronauts will help with the spacewalk by operating the station’s robotic arm and giving directions from inside the orbiting space lab. The space station’s three crew members today planned to pack up materials and rubbish that needs to be taken back to Earth.

The shuttle’s crew awoke today to a recording of Coldplay’s Clocks, which was requested by Sellers' family.

The shuttle’s astronauts got welcome news yesterday when Nasa managers cleared Discovery’s thermal protective skin as safe to return to Earth next Monday. Hundreds of images of Discovery were taken during lift-off, in-flight to the space station and before docking with the complex to make sure the shuttle doesn’t have any damage like the kind that doomed Columbia’s seven astronauts in 2003.