Washington, Jan 1 (IANS) From a fuzzy beginning nearly 20 years ago, Hubble Space Telescope has now revolutionised astronomy, its stunning images stirring global imagination.But as the International Year of Astronomy dawns, the renowned telescope is preparing for its final chapter, starting with the scheduled May 12 launch of the space shuttle Atlantis for NASA’s fifth and final service mission to the telescope.

The repairs will provide Hubble with a future as bright, though perhaps not nearly as long, as its past, said Julianne Dalcanton, a University of Washington (UW) associate professor of astronomy who has used the telescope for much of her research.

She attributes Hubble’s success to the fact that it orbits nearly 560 km above the Earth, far removed from the atmosphere and ambient light that limit the effectiveness of ground-based telescopes, said a UW release.

The upcoming servicing mission will likely allow Hubble to add to its already rich legacy of scientific discovery, she added.

That legacy includes helping to revolutionise astronomers’ understanding of phenomena called black holes and their role in forming galaxies; more detailed observations of pulsating stars called Cepheids that enhanced the ability to judge the huge distances involved in stellar astronomy; and, most recently, producing an image, the first direct evidence, of a planet orbiting a star outside our solar system.

“One of the things Hubble has done is enhance the precision with which we can carry out research,” Dalcanton said. “And the images produced have really spurred public interest. Those pictures are on screen savers throughout the world.”

Hubble was launched on April 24, 1990, as a joint venture of NASA, the European Space Agency and the Space Telescope Science Institute.

But the mission got off to a rocky start when it was discovered that an error had been made in fabricating the main mirror and its images were often fuzzy at best.

The problem was corrected on NASA’s first service mission in 1993 and the telescope has been wildly successful ever since.

The upcoming service mission, among other things, will replace gyroscopes and heat shields, upgrade instruments and add “some spiffy new capabilities that will allow us to make much deeper observations”, Dalcanton said.

The study was published in Thursday’s edition of Nature.