Astronauts aboard the International Space Station are performing a spacewalk Thursday to work on parts of the station.
The outing by Americans Randy Bresnik and Mark Vande Hei ended at 3pm (3am on Friday Singapore time), marking a "very successful day", a Nasa spokesman said.
Five days from now, on October 10th, Bresnik and Vande Hei will do another spacewalk to lubricate the new LEE and then replace a camera on the outside of the station. The two identical LEEs of Canadarm2 are used to grapple incoming cargo vehicles and payloads and to provide data and telemetry to the rest of the Canadian-built Mobile Base System.
Canadarm2, the Canadian robotic arm is one of the essential tools on the ISS.
"It's more gorgeous and heavenly than I saw when I was out here eight years ago", Bresnik, a spacewalk veteran, marveled as he floated out of the airlock 250 miles above Africa.
For identification, Bresnik, call sign EV-1, is using helmet camera 18 and wearing a suit with red stripes. It hasn't caused any slowdown in standard ISS operations, and the crew keeps a spare LEE around in case of just such an emergency.
"Since these components are well beyond their design life, this really is expected wear and tear on the arm", Braithwaite said.
They replaced one of two Latching End Effectors (LEE) which had lost the ability to grip effectively, said the United States space agency.
The second and third spacewalks will concentrate on the lubrication of the LEE and the installation of a pair of external cameras. While this will be the first-ever spacewalk of the latter, it will mark the third one of Bresnik.