The residents of the International Space Station completed a 4-hour, 30-minute spacewalk today. The crew installed communications equipment on the exterior of the Zvezda Service Module and deployed a small satellite experiment.
The equipment installation was part of the preparation for the maiden docking of the European Space Agency’s cargo carrier, the Automated Transfer Vehicle (ATV). The ATV named “Jules Verne” is due to launch next year. With no crew inside, Station systems were either deactivated or put in autonomous operation for the duration of the spacewalk. Hatches were 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.
Clad in Russian Orlan spacesuits, Expedition 10 Commander and NASA Science Officer Leroy Chiao and Flight Engineer Salizhan Sharipov left the Station’s Pirs Docking Compartment airlock at 1:25 a.m. EST. They quickly set up tools and tethers for their excursion, and Sharipov activated the Russian Nanosatellite for later deployment.
The first primary task was the installation of three space-to-space communications, known by the Russian acronym WAL, antennas on the forward conical section of Zvezda. The S-band low gain antennas are part of the Proximity Communications Equipment (PCE). They will be used for ATV and Service Module interaction during future rendezvous and docking operations. The first three antennas were installed on the aft end of Zvezda during Expedition 9.
About two hours into the spacewalk, from a ladder attached to Pirs, Sharipov deployed the foot-long, 11-pound Nanosatellite toward the aft end of the Station. Chiao photographed its departure. The experiment contains a transmitter. While it orbits Earth it is expected to help develop small satellite control techniques, monitor operations and develop new attitude system sensors. Russian experts informed the crew, they received a good signal from the satellite two hours after its deployment.
The spacewalkers gathered the tools and equipment for the next task, as Russian flight controllers inhibited thrusters from firing in the next worksite. Once that was complete, the crewmembers were given approval to move toward the aft end of Zvezda. Once in place, they installed a Global Positioning System receiver. The receiver is also part of the ATV communications hardware. It will give the approaching vehicle data about its relative position to the Station during rendezvous operations.
Chiao and Sharipov also inspected and photographed an antenna used for communications with the Service Module to confirm its position for Russian technicians. Chiao photographed a previously installed laser reflector that will also be used for ATV proximity operations. The crew continued to secure cabling on Zvezda, as they worked their way back toward Pirs.
The two remaining gyros on the Station maintained attitude, or position in space, without Russian thrusters until just before the end of the spacewalk. They maintained attitude despite the recent loss of one of the three functioning Control Moment Gyroscopes, because of a circuit breaker failure. The Station drifted slightly without attitude control for less than 20 minutes. When Chiao and Sharipov reported they were a safe distance from Zvezda’s thrusters, the jets were reactivated and attitude was quickly regained.
The crew entered Pirs and closed the hatch at 5:55 a.m. EST to complete their spacewalk one hour ahead of schedule. After repressurizing Pirs, Chiao and Sharipov were scheduled to return to the Station, remove their spacesuits, reactivate systems and open the hatches to the U.S. segment. The crew will begin its sleep period later this morning and enjoy a light-duty day Tuesday.
It was the second spacewalk for Sharipov and Chiao’s sixth. The pair logged almost 10 hours of spacewalk time during the two Expedition 10 excursions. Today’s spacewalk was the 58th in support of Station assembly and maintenance; 33rd staged from the Station itself; and the 15th from Pirs. A total of 348 hours and 15 minutes of spacewalk time has been logged during the Station’s lifetime.
For more information about NASA, crew activities aboard the Station, future launch dates and Station sighting opportunities from anywhere on the Earth, visit:
http://spaceflight.nasa.gov/