360The Hubble Space Telescope is launched
On 24 April 1990, the space shuttle Discovery carried the Hubble Space Telescope into orbit, and astronauts released it the next day. Above the blurring atmosphere, Hubble could see further and more sharply than telescopes on the ground. A flaw in its mirror was fixed by astronauts in 1993, and it has since made more than 1.5 million observations.
Earth's atmosphere blurs and blocks light from space. Astronomers had long dreamed of a telescope above the air.
The Hubble Space Telescope, built by NASA with the European Space Agency, was launched on the space shuttle Discovery on 24 April 1990 and released into orbit the next day, about 540 km above the Earth. Its main mirror is 2.4 m wide.
The first images were disappointing. The mirror had been ground to slightly the wrong shape, by about one fiftieth of the width of a human hair. In December 1993, astronauts fitted corrective optics during a spacewalking repair mission, and the pictures became sharp.
Hubble has helped measure the age of the universe at about 13.8 billion years, found that its expansion is speeding up, and shown that most galaxies have giant black holes at their centres. Its images, such as the 'Pillars of Creation', became famous worldwide.
Astronauts serviced it five times, the last in 2009. Hubble is still working, now alongside the James Webb Space Telescope.
- 24 April 1990
- Hubble is launched
- December 1993
- Astronauts fix its vision
- 1995
- The Hubble Deep Field image
- 2009
- The last servicing mission
Sources: NASA · ESA/Hubble · Space Telescope Science Institute.