116 Tools Not Enough on Fourth Spacewalk

HOUSTON, May 17, 2009 — -- The Hubble Space Telescope has lasted for 19 years, because it was designed mostly with parts that astronauts could replace on spacewalks.

Not on this mission.

A key instrument -- a spectrograph that can, among other things, measure the chemical composition of distant objects in the cosmos -- had lost power. NASA decided that instead of replacing the whole thing, it would have the astronauts fix it by hand on the fourth spacewalk of their mission to repair Hubble.

The job fell to spacewalker Mike Massimino, who had his work cut out for him. He had to remove more than 110 small screws.

"It is a repair activity that was not meant to be fixed up in space," said Tomas Gonzalez Torres, NASA's lead spacewalk officer, "with boxing gloves, with big huge gloves, in a big marshmallow suit."

There are 116 tools in the tool kit on Atlantis to fix the Hubble Space Telescope, including a bolt puller vise grip Massimino used to remove a balky bolt from a cover on a panel.

But even with all their tools, Massimino and crewmate Mike Good fell three hours behind.

At one point, Houston sent Massimino back to the space shuttle's airlock to refill the oxygen in his backpack.

In the end, the astronauts wrapped up what was scheduled as a 6½-hour spacewalk after eight hours, putting off other work until Monday.