Steve Robinson and Soichi Noguchi successfully installed a new gyroscope, which is a control moment device designed to ensure that the station maintains its proper position relative to Earth, to replace one that had not worked properly since 2002. They were making the second space walk of their current mission with the Discovery space shuttle.
Although the astronauts lost some time before they left the station, a NASA expert said they had made it up and were even working ahead of schedule.
According to the expert, the shuttle crew will be able to test the new device after Robinson and Noguchi return from the space walk.
He added that it might take several hours before the gyroscope's flywheel gains its full rotating momentum, which is when the crew can make sure that the device is working properly.
The astronauts first ventured out of the shuttle Saturday. They tested gluing materials for repairs on the shuttle's heat shield and switched the second gyroscope back on, which meant that three such devices on board the craft were operational.
Four gyroscopes are needed to maintain the space station's stability. After today's spacewalk, all four gyroscopes on board the ISS will be put into operation, which will provide enough kinetic energy to maintain the station's position.
