Clad in Russian Orlan spacesuits, Expedition 10 Commander and NASA Science Officer Leroy Chiao and Flight Engineer Salizhan Sharipov left the Pirs Docking Compartment airlock at 1:43 a.m. CST and quickly set up tools and tethers for their excursion. With no one left inside, Station systems were either deactivated or put in autonomous operation for the duration of the spacewalk. Hatches were also closed between the U.S. and Russian segments of the complex in the unlikely event the crew would not have been able to return to the outpost.
The first order of business was the installation of a Universal Work Platform at the forward end of the large conical section of Zvezda. Atop the platform they mounted a German commercial experiment called Rokviss (Robotics Component Verification on ISS).
The Rokviss consists of a small double-jointed manipulator arm, an illumination system and a power supply. An antenna for the robotic device to receive commands was also installed by Chiao and Sharipov along with cabling. At first the antenna did not receive the proper power. Chiao and Sharipov returned to the antenna work site and remated two electrical connectors. Russian engineers then reported that the Rokviss system was operating normally.
The system is designed to be commanded by operators on the ground in Germany. It can also be operated by the crew from a workstation inside Zvezda. Rokviss will test the ability of lightweight robotic joints to operate in the vacuum of space for future assembly work or satellite repair and servicing.
Chiao and Sharipov moved a Japanese commercial experiment from one bracket on the outside of Zvezda to an adjacent bracket. The experiment, first deployed on Station by the Expedition 3 crew in October 2001, resembles an open attaché case and is designed to collect data on micrometeoroid impacts and the effect of the microgravity environment on a number of materials housed on witness plates.
Chiao and Sharipov then moved to another section of Zvezda to inspect nearby environmental system vents that are used for the Elektron oxygen-generator, the Vozdukh carbon dioxide scrubber and a particle contaminant purification device.
Sharipov reported that he saw both a white and brownish residue near the Elektron and Vozdukh ports and what appeared to be an oily substance on insulation surrounding the ports. Russian specialists added the task to the spacewalk a few weeks ago in light of recent technical problems with those systems, and will analyze photos taken by Sharipov to see if any corrosion or clogging of the vent ports may have contributed to periodic problems with those components.
As the spacewalk drew to a close, Chiao and Sharipov installed a Russian experiment called Biorisk near the hatch to the Pirs airlock. Biorisk consists of several canisters on a bracket that contain microorganisms and materials that will collect data on the effect of the space environment for ecological analysis back on Earth.
With their work complete, Chiao and Sharipov returned to Pirs and closed the hatch at 7:11a.m. CST to complete their spacewalk. After repressurizing Pirs, Chiao and Sharipov were scheduled to return to the Station, remove their spacesuits, reactivate the ISS systems and open the hatches to the U.S. segment. The crew will begin its sleep period early this afternoon and enjoy an off-duty day on Thursday.
It was the first spacewalk for Sharipov and Chiao's fifth. The excursion was the 57th in support of ISS assembly and maintenance, the 32nd staged from the ISS itself and the 14th from Pirs. A total of 343 hours and 45 minutes of spacewalking time has been logged in the Station's lifetime.
Chiao and Sharipov are scheduled to conduct a second spacewalk in late March to install additional equipment for the maiden arrival of the European Space Agency's "Jules Verne" Automated Transfer Vehicle (ATV) cargo ship. The unpiloted cargo carrier is targeted for launch late this year.