Hubble craft prepares for launch
2009-04-01 08:20
Cape Canaveral - The space
shuttle that will carry Nasa's last crew to upgrade the Hubble
Space Telescope was moved to its Florida launch pad on Tuesday
in preparation for lift-off on May 12.
Shuttle Atlantis and its crew of seven astronauts were due
to launch six months ago, but the failure of a computer aboard
Hubble prompted Nasa to delay the flight.
Replacing the computer, which prepares data from Hubble's
science instruments to be relayed back to Earth, was added to
the long list of chores the astronauts will tackle during five
days of spacewalks.
Hubble, which has been using a backup computer to format
its science data, has been operating well, but is only expected
to last another couple of years without another servicing call
by shuttle astronauts. Astronomers view Hubble as an important
source of scientific data about the universe.
Riding atop a slow-moving Apollo-era transporter, Atlantis
emerged from the Kennedy Space Centre's assembly building at
around 04:00 EDT (0800 GMT) to begin the 5.6km
trek to the seaside shuttle launch complex. The ride took more
than six hours.
In three weeks, Atlantis will be joined by shuttle
Endeavour on a nearby launch pad that is being refurbished for
use by the Orion spaceships set to replace the shuttles.
Nasa wants a second shuttle ready to fly in case Atlantis
sustains critical damage during launch, as its crew will not be
within range of the International Space Station to seek shelter
while a possible rescue mission is prepared.
Rescue plans
In-flight inspections and rescue plans have been part of
all Nasa shuttle missions since the fleet returned to flight
following the 2003 loss of Columbia.
Seven astronauts died when the shuttle broke apart as it
headed for a landing in Florida, the result of a heat shield
breach caused by a piece of falling foam debris during liftoff
16 days earlier.
In addition to tracing the roots of the accident,
investigators recommended that the remaining three shuttles be
retired upon completion of the space station, which depends on
the shuttle for construction.
The US space agency expects to
finish the $100bn orbital outpost, a project involving 16
countries, next year and retire the fleet.
After the accident, then-Nasa administrator Sean O'Keefe
cancelled the fifth and final servicing call to Hubble, saying
it was too risky.
One of the first orders of business for
O'Keefe's replacement was to re-examine the issue.
Nasa drew up alternative plans for a rescue and other
safety enhancements, and the mission to return to the telescope
was restored to the shuttle's manifest.
In addition to installing new batteries, gyroscopes and the
replacement computer, Hubble is due to receive a new camera to
extend its vision into ultraviolet and infrared wavelengths and
a light-splitting spectrograph sensitive enough to analyse
photons emitted from the universe's earliest galaxies.
After the upgrades, Hubble is expected to remain
operational until at least 2013.