Nasa today marks the anniversary of the launch of the Hubble Telescope, which was sent into space 25 years ago today.
The world-famous telescope was launched on 24 April, 1990, on board the Space Shuttle Discovery carrying five instruments - The Wide Field/Planetary Camera, the Goddard High Resolution Spectrograph, the Faint Object Camera, the Faint Object Spectrograph and the High Speed Photometer.
The idea for the telescope was first proposed in 1923 by German scientist Hermann Oberth, who suggested putting a telescope into space on a rocket. The idea became the life project of Lyman Spitzer Jr, who spent 50 years making the idea a reality.
US Congress finally approved funding for Hubble in 1977 and an initial launch date was scheduled for 1986. However, the Space Shuttle Challenger exploded just over 60 seconds into its flight. Four years later and a lot of tweaks later, it was finally sent into space.
The first few years were a massive disappointment. The images being returned were blurry and scientists worked out there was a problem with one of the mirrors. A repair crew was eventually sent up in 1993 and sorted out the problem.
Since then, Hubble discoveries have completely changed how scientists look at the universe. It also led to some fundamental insights including the age of the universe, the discovery of dark energy – and that the universe is expanding at an ever increasing rate.
"You talk about the scientific achievements themselves, some of them were not even imagined when Hubble was launched," Jennifer J. Wiseman, Hubble Space Telescope Senior Project Scientist at Nasa's Goddard Space Flight Centre, told IBTimes UK.
To find out more about Hubble see our full coverage of Hubble at 25 below.