Astronauts start space walk to repair station

Two astronauts stepped outside the hatch today for the second of what could be a precedent-setting three spacewalks in nine days, making repairs to the international space station’s cooling system.

The effort to finish hooking up ammonia cooling loops from a temporary to a permanent system outside the space station started at 12.38 GMT.

Astronauts Michael Lopez-Alegria and Sunita Williams planned to complete almost identical tasks to the ones they did during their first spacewalk on Wednesday: unplugging cables from a temporary cooling system and connecting them to the permanent system and covering up an obsolete radiator that removed heat from the space station.

“I’m coming out,” Williams said as she stepped outside the hatch.

The third spacewalk is set for Thursday, marking the first time three spacewalks have been conducted in such a short time at the space station without a space shuttle docked to it. Lopez-Alegria planned to conduct a fourth spacewalk with Russian flight engineer Mikhail Tyurin on February 22.

If the schedule stays in place, both US astronauts would hold spacewalking records by the end of the month. Williams will hold the record for the most by a woman, and Lopez-Alegria will be the US champion, surpassed only by Russian cosmonaut Anatoly Solovyov for the all-time record.

Both astronauts were wary of the possibility of toxic ammonia leaking from the cooling lines, something that occurred during a similar spacewalk by astronaut Robert Curbeam in 2001. During Wednesday’s spacewalk, four or five flakes of ammonia fell from a cooling line cap but did not touch the astronauts.

Nevertheless, Mission Control ordered the astronauts to take precautions against contamination since it could cause respiratory problems for the three-person crew if it got in the space station in significant amounts.