Saturday's spacewalk a success: Last hurdle completed

William Atkins
Saturday, 24 November 2007 19:59

Science - Space

Because all the spacewalking objectives were accomplished by astronauts Whitson and Tani, NASA mission control managers have decided to activate Harmony’s systems a day early, which if all goes well will give a clear go-ahead for space shuttle Atlantis, and the STS-122 mission, to launch on December 6, 2007.         

Beginning their spacewalk about 70 minutes early, at about 4:50 a.m. EST, Whitson and Tani linked up cooling system lines to the Harmony module from the space station on this spacewalk. They also connected Harmony with primary and backup connections to the space station’s electric power grid.

With all of their scheduled assignments successfully finished, the astronauts also made an inspection of the mechanism that rotates a faulty solar array on the space station’s right side.

Earlier in October 2007, during the STS-120 mission, Tani had made the discovery of metal shavings around the mechanism.

Collected and taken back to Earth by space shuttle Discovery for inspections, NASA scientists found that the metallic particles were from a circular bearing race in the rotating joint.

Bearing races are inner and outer rings, circular in this case, containing grooves where sets of balls loosely sit, all of which makes up the ball bearing.

Saturday’s inspection is geared toward looking inside the interior of the mechanism and finding out what is actually grinding the mechanism and forming the shavings. The knowledge learned in this task will hopefully help to develop a plan to fix the joint.

Besides the inspection of the faulty solar array joint, the spacewalking astronauts are also performing other “get-ahead” tasks while outside of the space station.

STS-122 is planned for a space shuttle Atlantis liftoff at 4:31:38 p.m. EST (21:31:38 UTC) on December 6, 2007, at launch pad 39A, at the Kennedy Space Center, in Florida. Details of STS-122 is found at the NASA webpage: Mission Information STS-122.