Wonders of the Universe. Andrew Cohen

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      The Hubble Space Telescope being repaired by an astronaut from Endeavour. This eleven-tonne telescope has allowed astronomers and scientists to see further into our universe than ever before.

       NASA

THE HUBBLE TELESCOPE

      The naked eye can only allow us to travel back in time to the beginnings of our species; a mere 2.5 million light years away. Until recently, Andromeda was the furthest we could look back unaided, but modern, more powerful telescopes now enable us to peer deeper and deeper into space, so that we can travel way beyond Andromeda, capturing a bounty of messengers laden with information from the far distant past.

      In the history of astronomy, no telescope since Galileo’s original has a greater impact than the eleven-tonne machine called Hubble. The Hubble Space Telescope was conceived in the 1970s and given the go-ahead by Congress during the tenure of President Jimmy Carter, with a launch date originally set for 1983. Named after Edwin Hubble, the man who discovered that the Universe is expanding, this complex project was plagued with problems from the start. By 1986, the telescope was ready for lift off, three years later than planned, and the new launch date was set for October of that year. But when the Challenger Space Shuttle broke apart seventy-three seconds into its launch in January 1986, the shutters came down not only on Hubble, but on the whole US space programme. Locked away in a clean room for the next four years, the storage costs alone for keeping Hubble in an envelope of pure nitrogen came to $6 million dollars a month.

      With the restart of the shuttle programme, the new launch date was set for 24 April 1990 and, seven years behind schedule, shuttle mission STS-31 launched Hubble into its planned orbit 600 kilometres (370 miles) above Earth. The promise of Hubble was simple: images from the depths of space unclouded by the distorting effects of Earth’s atmosphere. A new eye was about to open and gaze at the pristine heavens, but within weeks it was clear that Hubble’s vision was anything but 20:20. The returning images showed there was a significant optical flaw, and after preliminary investigations it slowly dawned on the Hubble team that after decades of planning and billions of dollars, the Hubble Space Telescope had been launched with a primary mirror that was minutely but disastrously misshapen. Designed to be the most perfect mirror ever constructed, Hubble’s shining retina was 2.2 thousandths of a millimetre out of shape, and as a result its vision of the Universe was ruined.

      Such was the value and promise of Hubble that an audacious mission was immediately conceived to fix it. This was possible because Hubble was designed to be the first, and to date only, telescope to be serviceable by astronauts in space. A new mirror could not be fitted, but by precisely calculating the disruptive effect of the faulty mirror, NASA engineers realised that they could correct the problem by fitting Hubble with spectacles.

      The Hubble Space Telescope has had a greater impact on astronomy than any other telescope. This huge telescope orbits Earth, sending back images of parts of the Universe that would otherwise remain invisible to us. The telescope has been orbiting Earth since 1990, and its revolutionary and revelatory journey continues to this day.

       NASA

      In December 1993, astronauts from the Shuttle Endeavour spent ten days refitting the telescope with new corrective equipment. In charge of the repairs, by far the most complex task ever undertaken by humans in Earth orbit, was astronaut Story Musgrave. Already a veteran of four shuttle flights, a test pilot with 16,000 flying hours in 160 aircraft types, ex-US Marine and trauma surgeon with seven graduate degrees, Musgrave is quite an extraordinary example of what people can do if they put their minds to it. He is a metaphor for the space programme itself; in Musgrave’s own words, this is what restoring sight to Hubble meant. ‘Majesty and magnificence of Hubble as a starship, a spaceship. To work on something so beautiful, to give it life again, to restore it to its heritage, to its conceived power. The work was worth it – significant. The passion was in the work, the passion was in the potentiality of Hubble Space Telescope.’

      Seven years behind schedule, shuttle mission STS-31 launched Hubble… A new eye was about to open and gaze at the pristine heavens…

      On 13 January 1994, NASA opened Hubble’s corrected eye to the Universe and opened the eyes of our planet to the extraordinary beauty of the cosmos. A decade late and costing around $6 billion dollars, it has proved to be worth every cent

      The Hubble Space Telescope has brought us incredible images of other galaxies that we might never have been able to see. This shot of the spiral galaxy NGC1300 is one of the largest images taken by the telescope.

       NASA

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