The Space Telescope was launched on April 24, 1990. In truth, the HST was not actually launched, because it was equipped with no rockets capable of propelling itself into orbit. In fact, it was "deployed" -- released -- by the Space Shuttle Discovery, after being delayed in 1986 when NASA temporarily suspended all Space Shuttle voyages after the Challenger exploded. For those who had worked on the project, it was a moment of triumph as the Space Shuttle's remote arm lifted the Hubble Space Telescope out of the cargo bay and sent it into orbit.
Photo. The Space Shuttle Discovery lifts off with the Hubble Space Telescope in its cargo bay. Courtesy NASA.
Despite the excitement of scientists that the gigantic observatory had been launched, when astronomers viewed its first images, they discovered problems. When the telescope went from darkness into sunlight, it vibrated. Light reflected from the primary mirror didn't focus properly. Though the images we saw were an improvement over photographs taken by the best ground based telescopes, they looked fuzzy.
Photo, left. A picture taken by a ground telescope of a star field in the 30 Doradus galaxy. Notice the blocky result because the resolution is too low for such great distances.
Photo, right. The view of the same star field from the flawed Hubble Space Telescope. The resolution here is clearly superior and the blurry image is spectacular, but the ill-focus left much to be desired.
Both courtesy Space Telescope Science Institute, NASA.
Scientists knew how to fix the jittering movement that occurred after the telescope went from darkness into sunlight. It was caused by the two solar arrays on Hubble's sides. When their temperature alternated between -150 degrees and +200 degrees, they began to flap due to thermal expansion and contraction. The primary mirror had the wrong curvature. It was too flat in the center. To save money, the mirror had not been thoroughly enough tested before the Space Telescope was launched.
