POSTED 21 MARCH 2002
7. What's making these gamma rays?
Astronaut hard at work on the latest repair mission to Hubble : NASA
An astronaut is dwarfed by the telescope. Solar arrays are at top, and the mechanical arm, used for servicing, in center. Shuttle bay is at bottom. NASA
Spacy mechanical masterpiece
Customer overheard at orbiting garage: "Take
out those dents on the fender, replace the generator, and don't forget
to fix the solar panels and positioning device." The rumors you've heard
are true: Hubble Space Telescope, like an aqua-and-white 1950's Nash Metropolitan
after its regular visit to the car-fix, has just finished another round
of repairs.
A great car for shade-tree mechanics, the '56 Nash Metropolitan
is smaller and simpler than the Hubble -- and a lot easier to work on. Courtesy
David Tenenbaum.
And while the Roadmaster may last only a few thousand miles before the carburetor clogs or the distributor cap cracks, a refurbished Hubble is going to continue orbiting Earth, making pictures that dazzle Earth-bound astronomers and star-lovers alike.
Sure, NASA didn't ask its mechanics to take out dents, and it certainly didn't drive the clunker into the shop. Instead, it flew the shop to the Buick. Nonetheless, Hubble did undergo a heavy schedule of swappin' parts, taking out the old, bolting in the new, and making good on its warranty.
Repair list:
Replace solar panels.
We can only imagine the aftermath: the astro-mechanics retire to the neighborhood space shuttle and guzzle beers they'd cooled in the vacuum of space. We can almost hear the banter. "Yah, you kin learn anything you need to fix an ol' beater like Hubble from working on a '50s Nash Metropolitan. We usta block it up on tree stumps and hoist the engine over a tree limb..."
Boo-hoo boo-boo
Seriously, Hubble may be the best $2 billion NASA ever spent.
From its position in orbit high above the atmosphere, Hubble has produced astonishing
images and data on black holes, star formation and destruction, and even the early
universe. It's fair to say Hubble has revolutionized astronomy.
We've rounded up nine of the scope's greatest hits for your delectation. But first, it's fair to remember that Hubble owes its entire reputation to the exploits of orbital wrench-turners. After all, the lofty telescope began life as NASA's most embarrassing boo-boo. Somehow, before the 1990 launch, nobody bothered to check the main mirror, and a 4-micron defect was not discovered until the mirror had not only left the shop, but Earth itself.
(We trust the new Advanced Camera for Surveys was checked out more thoroughly before launch ...)
The snafu forced NASA to mount its first repair mission. In 1993, astronauts installed corrective optics -- eyeglasses -- on the expensive observatory. The success of that mission marked a turning point in the history of astronomy as the newly goggled Hubble began returning astonishing pix of a universe much more violent -- and interesting -- than many astronomers had imagined.
During its next trip to the garage, in 1997, Hubble became able to see the infrared portion of the spectrum, courtesy of the Near Infrared Camera and Multi-Object Spectrometer. NICMOS, as it's called, can see through dust and grut. In slightly more technical terms, it offers (and may we offer a silent moment of gratitude) "slitless grism spectroscopy." (NICMOS just got a high-tech cooler on the recent repair mission.)
Using a space shuttle as an orbiting garage, astronauts
changed the oil and rotated the tires on the world's most productive telescope.
Fixing, always fixing
A second instrument added during the 1997 mission,
the Space Telescope Imaging
Spectrograph helped prove the existence of black holes -- objects
so dense that not even light can escape.
During the 1999 fix-up, NASA repaired some busted gyroscopes -- gyros are what allow Hubble to point steadily at distant stars. (Had the dilapidated original gyros not been replaced, the telescope was destined for the celestial scrapyard...) The mission also took care of other nuts and bolts: a faster computer and data recorder, a new transmitter, and an enhanced fine guidance sensor.
With all that work, we trust they had time to change the oil and rotate the tires... Finally, the 2002 mission bolted the new Advanced Camera for Surveys into place. The camera replaced the Faint Object Camera, which was the only remaining instrument of the four that blasted into orbit on Hubble.
By now, Hubble is more bionic than an 80-year-old marathoner. NASA has taken the equivalent of a '58 Buick, and added a new engine, digital dashboard, radial tires, air-conditioning, fuel injection, even heated seats.
You might still call it a Buick Roadmaster, but the refurbished model has new capabilities. It might even cruise cross-country without stopping at every garage in Nebraska....
The Advanced Camera for Surveys must be some Instamatic.
There are 1 2
3 4 5 6
7 8 9 10
11 12 pages in this feature.
Bibliography | Credits
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Terry Devitt, editor; Pamela Jackson, project assistant; S.V. Medaris, designer/illustrator; David Tenenbaum, feature writer; Amy Toburen, content development executive
©2002, University of Wisconsin, Board of Regents.