The Hubble Space Telescope or HST for short celebrates its 30th birthday this week. The telescope was launched on 24th April 1990. It is named after astronomer Edwin Hubble. The HST is in orbit around the Earth at a height of approximately 540 Km. The advantage of having a telescope like Hubble in space is that it does not have to look through the atmosphere. The pollution, moisture, cloud and air currents all affect images taken by Earth based telescopes but not space based telescopes like Hubble.
In 1968 NASA started looking at the possibility of a large space based telescope with funding eventually being secured in 1978. Work began on building the telescope and NASA planned to launch in 1983 aboard the Space Shuttle. One of the requirements when designing the HST was that it be “serviceable” by the Space Shuttle. This was to ensure a long service life given the huge cost involved. It is the only space telescope to have been designed that way and as we will find it it was good thinking.
The telescope was named after Edwin Hubble in 1983. He had provided evidence that the universe was expanding and this is something the Hubble space telescope would also study. At this stage the launch date had slipped to October 1986. However, the tragic accident involving the Challenger shuttle grounded the rest of the shuttle fleet which delayed the launch for a number of years. Shuttle launches resumed in 1988 and HST lifted off from the Kennedy Space Center in Florida on 24th April 1990.
Once in space, it became apparent there was a problem with Hubble. After analysis it was determined the 2.4 meter wide mirror had not been manufactured correctly. It was fixed by adding some new parts to the telescope during the first servicing mission in 1993. In total there has been five service missions to the HST (1,2,3A,3B and 4). The last flown by Space Shuttle Atlantis will be last to the HST and took place in May 2009. While there they fixed a number of vital components, changed batteries and added some new cameras.
Over its 30 year life Hubble has produced some of the most spectacular images ever seen. I have included two here. The first is called “Pillars of Creation” and shows a star forming region 6,500 light years from Earth. The second is called the “Hubble eXtreme Deep Field Image”. It shows approximately 5500 of the most distant galaxies ever seen. Some of which are so distant that the light left them 13.2 billion years ago.
Hubble eXtreme Deep Field 
Pillars of Creation
HST has made and continues to make huge contributions to science. Hubble has been used to study the age of the universe, the expansion of the universe, galaxies, the Solar System, black holes and much more. More than 15,000 scientific papers have included data from Hubble making it one of the most productive scientific instruments ever built. Hubble may have reached 30 but we hope that it continues to contribute to science for years to come. As of now NASA has allocated funding to continue operations until June 2021 but this may be extended.
Paul Smith 