A crew aboard the space shuttle 'Endeavor' successfully repaired the Hubble telescope in December of 1993.
At their 360-mile-high rendezvous, Endeavour's crew pulled the telescope onto a platform in the space shuttle's open cargo bay.
There, they attached new stabilizing gyroscopes necessary to guide the telescope, replaced its solar panels and gave it a new primary camera.
The wide-field planetary camera was responsible for about half of the Hubble's observations.
It had been sending to earth unfocused images due to a flaw in its primary mirror.
Hubble, which had been launched into space in 1990, had only been able to transmit bright images within 4 billion light-years rather than the optimal 10 to 15 billion.
The flaw had limited the observations of astronomers investigating theories of an expanding universe and the existence of black holes.