August 26, 2008. Copyright 2008, Graphic News. All rights reserved

Final shuttle mission to Hubble Space Telescope

LONDON, August 26, Graphic News: Shuttle mission STS-125, the long-awaited flight by the shuttle Atlantis to service and upgrade the Hubble Space Telescope (HST), is set to blast off from Kennedy Space Centre in Florida on October 8. 

Commander Scott Altman and his six crewmates -- pilot Gregory C. Johnson, robot arm operator Megan McArthur and spacewalkers John Grunsfeld, Michael Massimino, Andrew Feustel and Michael Good -- will conduct the final shuttle mission to the telescope, and more than likely the last visit before Hubble is de-orbited in the mid-2020s.

Ground crew at the Space Telescope Operations Control Centre (STOCC) at Goddard Space Flight Centre will place Hubble into hibernation and close the aperture door which protects the precious optical components. Mission specialist McArthur will then grapple the telescope with the robot arm and the first of five arduous back-to-back spacewalks will begin.

Two new instruments are to be installed: the Cosmic Origins Spectrograph (COS) -- which will explore the “cosmic web” in extreme ultraviolet frequencies -- and the Wide Field Camera 3 (WFC3), which will allow the telescope to “see” across the entire visible light spectrum, from ultraviolet to optical and infrared.

In addition, spacewalkers will install an upgraded fine guidance sensor, a new set of batteries and a full set of gyroscopes. They will also attempt to repair two key instruments: the Advanced Camera for Surveys (ACS) -- which failed in January -- and the Space Telescope Imaging Spectrograph (STIS), a sophisticated instrument which separates light from different celestial objects into its components, which failed in 2004.

After each spacewalk, while the astronauts are sleeping, ground crew at STOCC will perform tests to make sure each instrument and component has power and operates as it should.

If all goes to plan, the mission will leave the 17-year-old telescope at the apex of its capability, able to probe the Universe with a full set of instruments 90 times more powerful than ever before.

The 11-day service mission will be the fifth to Hubble, which orbits almost 560km (350 miles) above Earth. Launched with great fanfare in 1990 after long delays, the more than $3 billion instrument (financed by NASA but with contributions from the European Space Agency) initially did not work because of an embarrassing mistake in shaping its 2.4-metre mirror.

In 1993 the first-ever repair mission in orbit succeeded in installing corrective optics that allowed the telescope to begin sending back spectacular and often awe-inspiring images. Subsequent shuttle missions steadily upgraded the observatory and its capabilities, and Hubble gradually achieved iconic status.

Now regarded as one of the most important instruments in the history of astronomy, the HST has produced hard evidence for the existence of black holes, confirmed theories of planetary formation, and dramatically refined estimates of the age of the cosmos. The first new Hubble data and images are expected by early next year.
/ENDS