March 23, 2009

Astronauts Complete Final Spacewalk

Astronauts Joseph Acaba and Richard Arnold ventured outside the International Space Station on Monday for the third and final spacewalk of shuttle Discovery.

"Thanks again for going outside today," station commander Mike Fincke radioed to the spacewalkers.

"This is probably the last EVA (extravehicular activity, or spacewalk) for this Discovery mission. We just want to say take your time, enjoy it and do good work."

However, they were unable to complete one of their primary tasks "“ freeing a jammed equipment storage platform.

A pin was inserted upside down by Acaba and another astronaut on Sunday. They were able to loosen the pin from its position, but it did not solve the problem.

"I didn't even feel it move," Arnold said. "It's really stuck."

Armed with pry bars and hammers, Arnold and Acaba were "unable to fully deploy the Port 3 unpressurized cargo carrier attachment system (UCCAS)," NASA said.

"This is the system that Acaba and Steve Swanson previously attempted to deploy during Saturday's second spacewalk. Mission Control has advised the spacewalkers to cease deployment attempts and secure the UCCAS in place using long-duration tethers. This will protect the hardware until another attempt can be made sometime in the future."

"Because the problem is not yet understood, Mission Control cancelled Acaba and Arnold's installation of a similar payload attachment system on the starboard side," the space agency said in a statement on its Web site.

"I know it didn't turn out the way we wanted it to, but you guys did a great job," astronaut Steven Swanson radioed to Arnold and Acaba from inside the Discovery space shuttle.

On Sunday, Discovery found itself having to stay clear of the path of space junk yet again. Discovery crewmembers moved the shuttle and space station to increase drag to avoid the piece of debris.

"The debris is estimated to be about four inches in diameter, part of a spent Chinese satellite upper stage," NASA said.

Earlier last week, astronauts worked to attach the final pair of solar wings to the space station, in order to nearly double the amount of power onboard the ISS so that more crewmembers will be able to board the laboratory for longer periods of time.

The new set of 115-foot wings was successfully unfurled on Friday, bringing the total number to eight attached to the space station.

NASA said Discovery must return to Earth before a Russian Soyuz rocket launches on March 26 carrying a new set of crewmembers to the orbiting outpost.


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