Cosmonauts gear up for spacewalk
Cosmonauts Mikhail Kornienko and Fyodor Yurchikhin geared up for a planned six-hour spacewalk overnight Monday to replace a European docking camera on the back of the space station's Zvezda command module and to route cables to and from the new Rassvet docking compartment.
One set of cables will connect the KURS-P automated rendezvous system on the new module, allowing its use in future dockings. The other set will tie the module into the station's Russian command-and-control computer system.
(Photo: NASA TV)
One set of cables will connect the KURS-P automated rendezvous system on the new module, allowing its use in future dockings. The other set will tie the module into the station's Russian command-and-control computer system.
(Photo: NASA TV)This will be he 147th spacewalk devoted to station assembly and maintenance since construction began in 1998, the 11th so far this year, the fourth overall for Yurchikhin and the first for Kornienko. Both cosmonauts will be wearing Russian spacesuits.
The spacewalkers plan to open the hatch of the Pirs module around 11:45 p.m. EDT to officially kick off the excursion. The first item on the agenda is replacing a camera used by the European Space Agency's Automated Transfer Vehicle, or ATV, during final approach to the Zvezda module's aft port.
"The ATV is an unmanned spacecraft that brings supplies to the station, and the video camera is used to monitor the approach as it comes in and docks on the aft-end of the Zvezda module," said Chris Edelen, NASA’s lead spacewalk flight controller. "The video camera currently on-orbit has numerous bad pixels, resulting in degraded picture quality. So the new camera is expected to restore the system to its full functionality in time for next the ATV mission (in December)."
While ground controllers test the new camera, the cosmonauts will move forward along the space station "stack," dropping the old camera off at Pirs before making their way to the front of the Zvezda module. Four electrical cables, part of the Russian command-and-control system, will be plugged in and routed to the forward Zarya module. From there, the cables will be connected to the new Rassvet module attached to Zarya's Earth-facing port.
"First, a cable bundle will be run from the Zvezda and Zarya modules to connect the Rassvet to the Russian command and data handling computers," Edelen said. "Then, a second set of cables will be run from Rassvet to Zarya to provide full functionality of the KURS docking system to allow automated vehicle dockings of Progress and Soyuz spacecraft to the docking port at the bottom of the Rassvet module."
At the end of the spacewalk, Kornienko and Yurchikhin will move back to Pirs and jettison the old camera, releasing it in the opposite direction of the station's travel. Edelen said the camera is expected to re-enter the atmosphere and burn up in about four months.
"It will not be brought back inside the station due to concerns the insulation around the camera has degraded in the space environment and could result in fiberglass particles being shed inside the station resulting in a breathing hazard for the crew," Edelen said. "So at the end of the EVA, we will jettison the old ATV video camera."