NASA's High-Tech Lube Job on To-Do List for Spacewalk
Two NASA astronauts ventured outside the International Space Station today for a high-tech lube job, aiming to replace and grease joints that keep the outpost's solar panels facing the sun.
Heide Stefanyshyn-Piper and Steve Bowen, mission specialists from the U.S. shuttle Endeavour, exited an airlock at 1:09 p.m. New York time for a spacewalk expected to last almost seven hours, NASA Television showed.
The $100 billion space station depends on the sun to power its life-support systems and electronics. Problems surfaced about a year ago with the starboard joint that rotates one of two 240- foot (73-meter) sets of solar wings on the station.
A later spacewalk revealed that grinding gears were polluting the joint with metal shavings. The National Aeronautics and Space Administration says the creaky joint, which measures about 10 feet across, is responsible for power surges and vibrations aboard the station.
Stefanyshyn-Piper and Bowen today begin replacing a dozen bearings inside that joint, which measures about 10 feet across. Spacewalkers will make three more excursions to finish the job during Endeavour's 15-day mission.
Astronauts will carry a grease gun similar to ones used for applying caulk in home repairs. The lubricant, called Braycote, is durable enough to handle the extreme temperatures and vacuum of space, said Bill Jeffs, a spokesman at Johnson Space Center in Houston.
List of Tasks
Spacewalkers will also lubricate bearings on the port-side joint, which has been performing fine.
Today's tasks outside the station include removing an empty coolant tank, and readying the station's Japanese lab, Kibo, for an addition next year.
The International Space Station marks its 10th year in orbit on Nov. 20. The outpost is about three-quarters built, and NASA has set a 2010 deadline to finish U.S. work on the structure.
During the Endeavour's visit, astronauts inside will begin installing just-delivered bedrooms, a refrigerator, a gym and a device that recycles crew urine into drinking water. By early next year, the station will be able to accommodate a full-time crew of six, double the current capacity.
