Hubble was launched by the Space Shuttle Discovery on 25 April 1990, and opened a new era in astronomy.

However, the telescope, a cooperative effort of Nasa and the European Space Agency, would not be operational until 1993.
  
A mirror that had been improperly ground was corrected in 1993 when a new camera was also installed in the first repair mission by a space shuttle.
  
Once repaired, the telescope beamed back photographs 10 times sharper than before of galaxies, supernovas, giant explosions marking the death of a star, and the birth of a black hole.
  
Thanks to Hubble, flying above the atmospheric distortion that hinders even more powerful Earth-based telescopes, scientists have been able to confirm that the universe is rapidly expanding and to calculate precisely its age at 13.7 billion years, according to Nasa.  

Hubble's latest offering: The spiral
galaxy M51 - the Whirlpool Galaxy

Among other achievements, Hubble's observations allowed scientists to confirm the existence of a strange form of energy called dark energy, proved the existence of super-massive black holes, provided sharp views of a comet hitting Jupiter and showed that the process of forming planetary systems is common throughout the galaxy, Nasa said in a statement.
  
But the agency has so far decided not to send a shuttle to repair the aging telescope, citing the $450 million it would cost to do so. But the space agency's new chief, Michael Griffin, has said he would revisit the decision.
  
Astronauts have serviced Hubble four times, and many scientists hoped that a fifth service mission would be funded to enable Hubble to function to 2011, when its infrared replacement, the James Webb Space Telescope, is scheduled to arrive.
  
Currently, it is believed that Hubble's aging solar cells will provide enough energy to survive to 2007.