The commander of the International Space Station and one of his flight engineers spent a tedious but successful day outside the orbital complex on Wednesday hooking up a new cooling system.
The work was slow-going but accomplished its objective, with station chief Michael Lopez-Alegria and his partner, Sunita Williams, painstakingly disconnecting potentially leaky ammonia lines and delicately attaching the new system.
“That looked pretty difficult,” spacewalk engineer Chris Looper at the Mission Control Center in Houston, told the spacewalkers. “I feel for you.”
Work ran about an hour behind schedule and flight controllers decided to extend the crew’s usual time in the airlock, at the tail-end of their more than 7.5-hour walk, to make sure four suspected flakes of ammonia seen floating out from a line did not contaminate the crew’s spacesuits.
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Spacesuit contamination
Spacewalk coordinators had devised extensive procedures to handle contamination after an incident during a 2001 spacewalk when the original lines were installed. In that incident, a leaking connector sprayed ammonia into space, contaminating the spacesuit worn by astronaut Robert Curbeam. He spent extra time outside so the Sun could bake off the ammonia.
Lopez-Alegria and Williams have another set of lines to install during a spacewalk on Sunday to complete the installation of the new system.
The work is the most ambitious NASA has attempted on the half-built station without a space-shuttle crew present.
Busy year
Williams, who was making her second spacewalk, and Lopez-Alegria, on his seventh, also packed up a radiator panel that is no longer needed, an operation that went much more smoothly than the solar array wing retraction that gave the US space agency headaches during its last shuttle mission in December.
That flight left the $100-billion space station complex with a new electrical grid and the plumbing to replace the station’s temporary cooling loops with an integrated system.
The upgrades are needed to prepare the station for additional modules built by the European Space Agency and Japan.
The station is a multinational project, headed by the US and Russia. Partners include Canada, Japan, Brazil and 11 member nations of the European Space Agency.
Wednesday’s spacewalk was the first of a three-part series scheduled over nine days. The work kicks off a year of what is destined to be the busiest in space station assembly, with five Russian resupply missions, two Russian crew transfer flights, six shuttle construction missions and the first flight of Europe’s new cargo hauler.
