Simply stated, the 94.5-inch (2.4-meter) mirror was ground too flat by the tiniest of measures -- one-50th of the thickness of a strand of human hair. But the minute fabrication flaw was debilitating, seriously blurring all telescope images of stars, galaxies and other celestial objects.

Consequently, the nearsighted observatory fast became the butt of late night TV jokes and biting editorial page cartoons, driving some project scientists toward membership in The Hemlock Society.

"The journey down from Mount Everest not to the surface of Death Valley -- but perhaps about six feet under -- occurred only over the course of about two months," said Weiler, who at the time was chief scientist for the Hubble project.

"We had to explain to the American public that Hubble had a major flaw in its main mirror that would affect all the science we had to do."

Against unfavorable odds, shuttle astronauts in December 1993 outfitted Hubble with what amounted to a set of contact lenses, correcting its myopia. And the results of the repair work have been historic.

Unburdened by either atmospheric distortion or faulty vision, Hubble over the past nine years has uncovered decisive evidence of black holes and found proof positive of planets forming around distant stars.

Zooming in on fierce galactic collisions, the telescope has provided glimpses of celestial birth and death while shoring up the idea that a mysterious form of dark energy is pervasive in the universe -- a theory proposed but discarded by Albert Einstein in the early 1900s.

The universe, according to Hubble observations, is much younger than previously thought -- about 12 billion rather than 15 billion to 20 billion years old.

And the thought that the cosmos might ultimately collapse upon itself in a fatal "Big Crunch" has given way to the notion that the universe is infinitely expanding, accelerating outward in the wake of the primordial explosion known as "The Big Bang."

Next page: Hubble's impact on astronomy and culture