Sunday, May 17, 2009

Live: Handrail Snapped Free, Repair Continues

Mike Massimino's muscle has freed Atlantis spacewalkers from a jam - the second time human strength has overcome stubborn tools during efforts to upgrade the Hubble Space Telescope.

Just before 1 p.m., more than three hours into today's spacewalk, Massimino gave a hard yank to a handrail that was stuck in place because a stripped screw couldn't be removed with tools.

"It's off," Massimino said.

No NASA TV picures were available, but the astronauts reported no concern about debris floating loose where the handle broke off.

The success removing the handle allows Massimino and partner Mike Good to proceed with "regularly scheduled programming" that was expected to be the hard part of the spacewalk.

That's the placement of a capture plate over a panel from which 111 small screws and fasteners must be removed.

If that effort is successful, Massimino will try to replace an electronics card that could revive a "dead" spectrograph.

A power failure in 2004 knocked out all three channels of the Space Telescope Imaging Spectrograph, or STIS.

Fixing the STIS isn't considered essential to the mission's success.

But the instrument would provide back-up and complementary capabilities to the Cosmic Origins Spectrograph installed Saturday, so scientists are hopeful the fix is a success.

Today's work was expected to be more straightforward than Saturday's repair of a planetary camera, but that has not been the case so far.

Massimino was allowed a short break to regroup after snapping off the stubborn handrail.

During the mission's first spacewalk on Thursday, mission specialist Drew Feustel used raw strength to unscrew a balky bolt that held an old camera in place, rescuing the attempt to replace it with a more advanced model.

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