Morning Edition

Special Tools Required For Last Call To Hubble

Published May 11, 2009 1:36 AM

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The right tools can make any job easier, and that will be especially true this week when the Hubble Space Telescope gets its last tuneup.

When space shuttle Atlantis blasts off Monday on the final flight to Hubble, the astronauts will be carrying 180 special tools, and 116 of them were designed just for this mission, which involves tricky repairs to two science instruments that were never intended to be fixed in space. Liftoff is scheduled for 2:01 p.m. EDT.

The Hubble Space Telescope was launched in 1990. It has been serviced four times before, with the last servicing mission occurring in 2002.

"Over the last few years, we've seen significant deterioration within the set of scientific instruments that we provide to the astronomical community," says David Leckrone, senior project scientist for Hubble at NASA.

He says that after this visit, if all goes well, Hubble should be more powerful than ever before.

Astronauts are scheduled to go on five spacewalks to give the telescope an upgrade that includes new batteries and gyroscopes, and additional science instruments.

But some of the most ambitious repair work involves "actually going into the very guts of instruments that have suffered failures that were never meant to be touched on orbit," says Michael Weiss, deputy program manager for Hubble at NASA's Goddard Space Flight Center in Greenbelt, Md.

'The Zero-G Would Get It'

The astronauts will have to open up two instruments and replace electronics cards. Taking off the cover of one instrument, a spectrograph, involves unscrewing 111 tiny screws.

Weiss says a regular power drill from a hardware store wouldn't work in space. "Radiation would get it, the Zero-G would get it, the temperature extremes would get it," Weiss says. "It just wouldn't work in the space environment."

So for years, astronauts have used a special power tool in space. NASA engineers have designed a smaller, faster version of it for this mission.

Even though losing a few screws isn't a big deal when you're assembling a bookcase at home, in space it is potentially a serious problem. A wayward screw could float up into the telescope and cause damage.

"So we have to figure out a way for the astronaut to remove these screws but not let them float away in space," explains Jill McGuire, who heads the team at Goddard that designs tools for Hubble. "You can't, you know, hold a little tiny screw like this with a big astronaut glove on."

A Busy Board For Astronauts

McGuire's team solved the problem by designing a "fastener capture plate." It looks like a colorful busy board that toddlers might play with.

It's designed to fit exactly over the panel that needs to be removed. Once it's on, the screws will be covered by little plastic boxes, or bubbles. There's a tiny hole above each screw, for the astronaut to insert the screwdriver.

"The bit can actually get through the hole, to access the fastener head, but the fastener cannot get back out through the hole," McGuire explains. The captured screws simply float in the little compartments. They don't have to be screwed back in, because the old instrument cover will be replaced with a snap-on one.

Tools For 'What If' Scenarios

Many of the tools in the astronauts' tool kits were developed for scenarios that might not even happen.

For example, the astronauts will replace batteries that have been up there since 1990. Ben Kennedy, an engineer who works with the tool team, developed a battery extraction tool, in case those batteries are stuck and the astronauts can't just pull them off.

Of course, if the batteries come off easily, the astronauts won't ever use the tool.

"I think I hope that they don't have to use it," Kennedy says. "It's stowed in such a configuration in the shuttle that I think it will be visible in a couple of pictures, and I'll just be happy enough with that."

If all the repairs and upgrades go well, Hubble should be more powerful than ever, and will be able to take beautiful pictures of the universe until at least 2014.

After that, if the telescope breaks, it won't be repaired, says Edward Weiler, head of NASA's science mission directorate.

He says NASA is getting ready to retire the space shuttle program, so there won't be a vehicle that can go to Hubble, and the agency isn't building new spare parts for the Hubble Space Telescope.

"Nothing is being built for further servicing," Weiler says, "because to spend money on that would mean we wouldn't be able to build the next-generation telescopes."

And during this last visit to Hubble, astronauts will install a little mechanism that will allow a robotic spacecraft to capture Hubble at the end of its life and send it de-orbiting down toward the Pacific Ocean.

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RENEE MONTAGNE, host:

This is MORNING EDITION from NPR News. I'm Renee Montagne. When astronauts give the Hubble Space Telescope one last tune-up, they'll be using some unusual tools. Astronauts are scheduled to blast off this afternoon for the repair job on the 19-year-old telescope. NPR's Nell Greenfieldboyce went to see the tools they'll be using.

NELL GREENFIELDBOYCE: I recently visited Goddard Space Flight Center in Maryland to meet NASA's tool designers. They had some strange-looking devices out on a long metal table. Michael Weiss is a technical manager for Hubble. Here's what I asked him.

So what would happen if I just to K-Mart and got a Black and Decker drill and, like, took it up to space?

Mr. MICHAEL WEISS (Technical Manager Hubble at Goddard Space and Flight Center): It wouldn't work. Radiation would get it. The zero-g would get it. The temperature extremes would get it. It just wouldn't work in the space environment.

GREENFIELDBOYCE: It's been seven years since Hubble last got repaired. One scientist compared the aging telescope to an injured athlete who's playing through the pain. The telescope is still doing good science for now, but it needs some attention or things are really going to go bad.

Now, a lot of things on Hubble are relatively easy to fix. Things like gyroscopes and batteries are designed to be swapped out. But this mission involves more ambitious repairs to fix parts of two important science instruments.

Mr. WEISS: This time, it's not just new instruments and batteries and gyroscopes. It's actually going into the very guts of instruments that have suffered failures that were never meant to be touched on orbit.

GREENFIELDBOYCE: The tool team for Hubble is headed up by Jill McGuire. She says astronauts will have to open the instruments up so they can replace electronic circuit boards. Taking off just one cover means undoing 111 tiny screws.

Ms. JILL MCGUIRE (Hubble, Goddard Space and Flight Center): You can't, you know, hold a little tiny screw like this with a big astronaut glove on. So we have to figure out a way for the astronaut to remove these screws but not let them float away in space.

GREENFIELDBOYCE: The danger is a floating screw might find its way into the telescope and damage it.

Ms. MCGUIRE: So that's the whole purpose of this faster capture plate that you see here.

GREENFIELDBOYCE: Just at first glance, that looks absolutely nothing like a tool. It's this big flat blue board with all these knobs on it, and it looks like something you might give a precocious toddler to keep them from screaming in the back of you car.

(Soundbite of laughter)

Ms. MCGUIRE: Well, it is kind of a busy board.

GREENFIELDBOYCE: She says the board is designed to fit exactly over the panel that needs to be removed. Once it's on, the screws will be covered by little plastic boxes or bubbles. There's a tiny hole above each screw for the astronaut to insert the screwdriver.

Ms. MCGUIRE: The bit can actually get through the hole to access the fastener head, but the fastener cannot get back out through the hole.

GREENFIELDBOYCE: And then what happens to this screw? Does it float around in this little bubble?

Ms. MCGUIRE: Yes, exactly.

GREENFIELDBOYCE: The captured screws don't have to be screwed back in, because the old instrument cover will be replaced with one that snaps on.

(Soundbite of drill)

GREENFIELDBOYCE: To deal with all these screws, the gang came up with a smaller, faster version of the power tool that's been used on orbit for years. All told, the astronauts will carry up 180 tools. Most are brand new, and a lot were developed for what-if scenarios that might not even happen.

For example, the astronauts will replace batteries that have been up there since 1990. So an engineer named Ben Kennedy developed a battery extraction tool, in case those batteries are stuck and the astronauts can't just pull them off.

Mr. BEN KENNEDY (Engineer): This one will actually grab the same handles on the battery that the astronaut would grab. And it has two lifts on either side that'll actually pry the battery off the door.

GREENFIELDBOYCE: But if they just, like, take the batteries out, then they don't use your tool.

Mr. KENNEDY: Correct.

GREENFIELDBOYCE: So how - where are your feelings on this? Because on the one hand, you don't want things to go wrong. On the other hand…

Mr. KENNEDY: Yeah, it's - I think I hope that they don't have to use it. But it's stowed in such a configuration in the shuttle that I think it will be visible in a couple of pictures. And I'll just be happy enough with that.

GREENFIELDBOYCE: If all the repairs and upgrades go well, Hubble should be more powerful than ever, and will be able to take beautiful pictures of the universe for at least another five years.

Nell Greenfieldboyce, NPR News.

MONTAGNE: And if you want to get a look inside the Hubble toolbox, we have a photo gallery for you at npr.org. Transcript provided by NPR, Copyright National Public Radio.

Source: NPR

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