1 a.m. CDT, Friday, June 2, 2006
Mission Control Center, Houston
International Space Station Status Report #06-27
The residents of the International Space Station ventured outside their orbital home Thursday night to conduct a 6-hour, 31-minute spacewalk to repair, retrieve and replace hardware on the U.S. and Russian segments of the complex.
Clad in Russian Orlan spacesuits, Expedition 13 Commander Pavel Vinogradov and NASA Flight Engineer and Science Officer Jeff Williams opened the hatch to the Pirs Docking Compartment airlock at 5:48 p.m. CDT to begin the 65th spacewalk devoted to station assembly and maintenance. It was the sixth spacewalk for Vinogradov and the second for Williams. The spacewalk began as the station flew 220 miles over southern Asia.
After setting up tools and tethers outside Pirs, Vinogradov and Williams used the telescoping boom, designated Strela and attached to the airlock, to transport them to the forward area of the Zvezda Service Module that connects to the Zarya Module. There, Vinogradov installed a new nozzle to a valve that helps vent hydrogen into space from the Elektron oxygen-generator in Zvezda. Elektron uses the process of electrolysis to separate hydrogen and oxygen from water in the system. Oxygen is circulated into the cabin atmosphere while hydrogen is vented overboard. A nozzle on the hull of Zvezda used for that purpose previously had become clogged, reducing Elektron’s efficiency and forcing Elektron to use the same vent line employed by a contamination monitoring device.
Two weeks ago, Vinogradov rigged a vent line inside Zvezda as the precursor to the installation of the new vent valve nozzle on the exterior of the module. The refurbished Elektron is scheduled to be reactivated on Monday.
Next, the two moved to the aft end of Zvezda where they took pictures of one of several antennas designed to provide navigational information for the unpiloted docking of the European Automated Transfer Vehicle (ATV), scheduled to make its maiden flight next year. Russian engineers suspect the antenna’s cable may have prevented a cover on one of Zvezda’s reboost engines from opening during an aborted test firing earlier this year.
Later, Vinogradov took up cable slack from another ATV navigation antenna and took pictures for technicians to study.
While on the Russian segment of the station, Vinogradov removed a device called Kromka from Zvezda’s hull that has collected jet thruster residue while Williams retrieved the third in a series of three canisters from the outside of Pirs in an experiment called Biorisk that studied the effect of the space environment on microorganisms. Both Kromka and Biorisk were brought inside and will be returned to Earth.
Williams also collected a contamination monitoring unit from Pirs and returned it to the cabin for later analysis.
With the crew slightly behind schedule, a decision was made to extend the maximum time for the spacewalk. Following that decision, control of the spacewalk was handed from the Russian flight control team at the Russian Mission Control Center outside Moscow to the U.S. flight control team at Mission Control Houston, as planned.
Vinogradov and Williams maneuvered themselves on the Strela to the juncture of the Russian and U.S. segments of the outpost, and then moved to the station’s truss. They removed a video camera on the Mobile Base System that sits upon a rail car that moves up and down the truss to position the station’s robotic arm for assembly work. They replaced the camera, which failed in February 2005, with a new one.
Russian flight controllers reassumed responsibility for the spacewalk as Vinogradov and Williams used Strela to move back to the Pirs Docking Compartment. They re-entered the station and closed the hatch at 12:19 a.m. CDT to conclude their excursion.
The crew will reactivate station systems early this morning and open up the internal hatches between the U.S. and Russian segments before beginning a sleep period that will extend into Friday afternoon. Vinogradov and Williams will enjoy a few days of relaxation through early next week.
The next station status report will be issued on Friday, June 9, or earlier if events warrant. For more about the crew's activities and station sighting opportunities, visit: http://www.nasa.gov/station
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