Spacewalkers fix up station

Two spacewalking repairmen rigged up a new ventilation system outside the International Space Station late Thursday, completing a key step to reviving a problem-plagued Russian oxygen generator.

Pavel Vinogradov and Jeff Williams also replaced a broken camera on the U.S. segment of the outpost, a job NASA wanted done before assembly of the half-bult outpost begins again during a shuttle mission set for launch Aug. 28.

Image note: Click to enlarge the Associated Press photo captured from NASA TV.

The six-hour, 31-minute excursion was the 65th spacewalk devoted to the operation and maintenance of the outpost, the first component of which was launched in November 1998. Total time spent spacewalking at the station since then: 390 hours and 54 minutes.

The camera swap was the last major chore for Vinogradov and Williams.

Working together 220 miles above Earth, the two unbolted the broken camera from its mounting point on a small rail cart that also serves as a mobile work platform for the station's Canadian-built construction crane.

A new camera was put in place. It will provide station assembly crews with an extra and important view of construction work still to be completed at the outpost.

U.S. and Russian flight controllers considered canceling the work because the spacewalkers ran a little behind schedule. Russian spacewalks normally last no longer than six hours due to life support limitations with Orlan suits. But Russian flight controllers ultimately decided the suits had plenty of battery power and that air supplies and other consumables were adequate enough to extend the planned five-hour, 41-minute spacewalk.

Vinogradov and Williams also ran into a little trouble. Part of a foot restraint used to anchor Vinogradov onto a construction boom was detached and floated by a fragile solar array. No damage was done.

Earlier, Vinogradov repositioned cables associated with two navigation antennas on the rear end of the station's Russian command and control module.

One of them was blocking an engine cover, preventing it from being fired. The other needed to be positioned properly to guide a new European cargo carrier to docking on its first flight next year.

Vinogradov also retrieved a witness plate mounted near jet thrusters. Residue built up on the plate will help engineers determine how much toxic fuel contaminants are spewed into the area around the aft end of the module.

Williams retrieved a package of biology experiments and a contamination monitoring experiment that were mounted on handrails outside the Russian Pirs airlock.

The two already had finished their first major task: Installing a new hydrogen vent valve on the forward end of the command and control module, dubbed Zvezda, or "star" by the Russian Federal Space Agency.

The replacement appeared to be a little more difficult than anticipated. Vinogradov huffed and puffed his way through the task, which he carried out while anchored to the end of a telescoping construction boom.

The work should enable Vinogradov and Williams to coax a balky Russian oxygen generation system back into operation early next week.