CAPE CANAVERAL — Two American astronauts will venture outside the International Space Station Monday to stow a failed coolant pump and extend the outpost's Canadian railway.
Wearing protective spacesuits in a deadly vacuum(真空) environment, Stephen Bowen and Al Drew will exit the U.S. Quest airlock at 11:18 a.m.
The spacewalk（太空漫步） will be the 154th performed since the first two station building blocks were linked in late 1998.
A late substitute for original lead spacewalker Tim Kopra, Bowen only had a month to train for the dangerous work.
"Steve brings a wealth of (spacewalking) experience," NASA flight director David Korth said Sunday. "He's a very seasoned shuttle astronaut, and he picked up quickly in (training) runs, coming up to speed on the path that we have."Kopra was injured in a mid-January bicycle accident. Bowen, who flew aboard Atlantis last May, is a veteran of five spacewalks and is the first U.S. astronaut to fly consecutive missions.
PHOTO GALLERY: Discovery's final mission"He'll be just fine, and we have absolutely every confidence that we'll knock out all these tasks," Korth said.
Drew will be making his first spacewalk.
Their tasks include:
— Rigging up an electrical extension cable between the U.S. Unity module and the Quest airlock.
The cable routes power to airlock heaters. Adding an extension will make future maintenance work easier once Discovery's prime payload — a permanent stowage unit — is put in place on Unity's Earth-facing port.
— Moving a refrigerator-sized ammonia pump to an external stowage platform. The pump failed last August.
— Installing a new section of track for the Canadian rail car system that runs atop the station's 335-foot-long central truss and is used for moving cargo.
— Canting a video camera stanchion to provide clearance from an external stowage platform installed Saturday.
Still to come: a decision on a proposal to do a fly-around to document the first and only time a U.S. shuttle, a Russian Soyuz space taxi and cargo carriers from Russian, Japan and Europe all are docked at the complex.
Landing at Kennedy Space Center is set for March 7.（本文由在线英语听力室整理编辑） |