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CAPE CANAVERAL, Florida - Two Russian crew members ventured out from the International Space Station today to install metal shields designed to protect the vulnerable research outpost from the impact of orbital debris.
Station commander Fyodor Yurchikhin and flight engineer Oleg Kotov floated out of an airlock on the Russian side of the station and were back inside about five and a half hours later.
During the outing, the cosmonauts fitted five aluminum debris impact shields to the forward part of the crew's living quarters, a Russian-built module known as Zvezda that has been in orbit seven years. The shields measuring about 0.6 meter by 0.9 meter and weigh between 6.8 and 9.0 kg.
Nasa wants the Russian module upgraded to meet US safety standards. It was launched despite the substandard shielding after Russia and the United States agreed to upgrade the structure once it was in orbit.
That work began in 2002, but was interrupted by the 2003 Columbia disaster and subsequent grounding of the space shuttle fleet.
The bulk of the shields were delivered during Nasa's last shuttle mission to the outpost in December 2006.
At (28,162 kph) even something as small as a fleck of paint can cause severe damage to the station.
An impact with orbital debris "is our biggest risk," said Kirk Shireman, Nasa's space station deputy program manager.
During today's spacewalk, the cosmonauts attached five of the 17 remaining panels. The rest of the shields will be installed during a spacewalk slated for June 6.
Other shielding upgrades to Russian-made station components are pending.
If all the improvements are made, the chance a piece of debris or a micrometeoroid would puncture the outpost drops to 29 per cent from 55 per cent over the station's expected 15-year life, according to an independent task force report published in February that studied the issue for Nasa and Congress.
Construction of the US$100-billion, 16-nation project is scheduled for completion in 2010, at which time the shuttle fleet is to be retired.
Also today, Nasa managers began a two-day meeting at the Kennedy Space Center in Florida to determine if shuttle Atlantis is ready to resume flying.
The shuttle's fuel tank was hammered in a February hail storm, delaying the US space agency's first mission of the year for three months. The shuttle and a crew of seven astronauts are now scheduled for liftoff on June 8.
- REUTERS
