The two spacewalkers
will move a Latching End Effector (LEE), or hand, for the Canadian-built robotic arm, Canadarm2, from a payload attachment on the stations Mobile Base System rail car to the Quest airlock.
The work site is about 200 feet from the astronauts' exit, about as far as spacewalkers
safely can go.
Early in Friday's outing, the spacewalkers
reported seeing flakes of ammonia when disconnecting some of the equipment, but the crew was never in any danger, said NASA commentator Rob Navias.
From their rigorous training, to learning how to use power tools in zero gravity while wearing bulky gloves, to their impressions of opening the hatch and stepping outside into airless void, Canadian Spacewalkers
is a compelling blend of science, discovery, and the ultimate travelogue, illustrated with full-color photography throughout.
EVA38 ANIMATION/NASA: This animation depicts spacewalkers
Alexander Skvartsov and Oleg Artemyev working outside the Russian segment of the International Space Station for about 6.
NASA mission control in Houston checked in with them frequently to see if they were experiencing any wetness in their helmets, and each time the spacewalkers
reported no problems.
NASA wanted to prevent a recurrence of the helmet flooding that nearly drowned an astronaut last summer, so Saturday's spacewalkers
had snorkels in their suits and water-absorbent pads in their helmets.
, or their steel tethers, have ever been struck by debris, though NASA astronaut Mike Massimino says astronauts practice returning to a vehicle if a spacesuit is punctured.
In the unbroken 1B-minute sequence that opens "Gravity," Cuaron, Lubezki and Webber have increased the difficulty exponentially, maneuvering the camera around the spacewalkers
as if it, too, is weightless.
Despite the lack of visible damage, Mission Control ordered the spacewalkers
to install a spare pump.
Alvin Drew and Stephen Bowen have been doing relatively minor jobs that will leave the orbiting lab in the best possible condition, once the space shuttles stops flying.
NASA considered adding an extra day to Discovery's visit so spacewalkers
Rick Mastracchio and Clay Anderson could venture outside for a fourth outing and install a spare nitrogen tank.