PROFILE: Hubble telescope beloved by astronomers

Washington
- The Hubble space telescope, which has glimpsed billions of years back
in time to the early days of galaxies, got a new lease on life last
October when NASA decided to include a service mission in its hectic
schedule. NASA officials confirmed Friday the mission date would be
September 11, 2008.

The decision took 18 months and extensive study of safety issues, NASA
director Michael Griffin said at the time. His announcement triggered a
half a minute of applause from workers at the Godddard Space Centre in
Maryland that operates Hubble.

Without servicing, Hubble could lose its ability to take pictures of
galaxy formations and boiling star nebulae by next year, scientists
said. A repair mission slated for 2004 was cancelled under pressure for
the aging shuttles to return to flight and finish construction on the
International Space Station before the heavy- lifting aircraft are
retired in 2010.

The 2003 Columbia shuttle disaster made planning for a repair mission
even more difficult, as NASA has spent the past two years launching
test flights in its cautious return to space. The success of the test
flights confinced Griffin and NASA to add a Hubble repair flight to the
schedule.

The prospect that Hubble would die in space alarmed international
scientists and worried school teachers who use internet photographs
from outer space - quasars and black holes and galaxy formations - to
inspire their students. NASA investigated, then dropped, the idea of
sending a robot to do the repairs.

The Hubble mission will have to carry out at least four or five space
walks to service the telescope, and be prepared to make extra walks to
repair any damages to the shuttle that occurs on takeoff.

Missions to the space station are easier because ISS crew is on hand to
help inspect the shuttle. The ISS also offers up to three months refuge
for visiting crew in case of an emergency.

The Hubble, which orbits 580 kilometres above Earth, offers neither.
That means the shuttle would have to survive on its own for up to 25
days, with the second shuttle on stand-by at a separate launch pad for
a rescue mission.

After years in planning, the 1.55-billion-dollar space telescope was
released from a shuttle in 1990, only to find its vision blurred by
small error one-fiftieth of the width of a human hair in its lens. It
produced blurry images barely better than those seen through Earth's
cloudy atmosphere.

"Word came back that Hubble couldn't see and it needed the most
expensive contact lens in world history," recalled Senator Barbara
Mikulski, a powerful Democrat and one of NASA's biggest boosters.

After the repair, Hubble became one of the most scientifically
productive spacecraft ever launched, peering 2.2 billion light years
away into the Abell 1689 galaxy, recording the minus-270-degree-
celsius-background glow from the Big Bang and producing jaw-dropping
images of swirling clouds of space matter in oranges, greens, yellows,
reds - the Crab Nebula, the starburst Galaxy Messier 82.

NASA's decision to scrap the Hubble provoked protests in the scientific
community, especially after US President George W Bush decided to
divert NASA money into a 12-billion-dollar new moon programme over five
years.

The space community took little consolation that Hubble's replacement,
the James Webb Space Telescope, is slated for launch in 2013. That
would still have left them with a three or four year gap with no window
on the universe.

With the new mission, Hubble can last at least until 2013.


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