The astronauts were inspecting their ship when they came across the nicks spread over four to five thermal tiles. -- PHOTO: NASA
HOUSTON - ASTRONAUTS on the shuttle Atlantis sailed toward a rendezvous with the Hubble Space Telescope on Wednesday, set to grab the 13.2-metre long observatory for an ambitious overhaul.
Shuttle astronauts have not worked on Hubble since March 2002. The rendezvous activities will bring Atlantis, with shuttle commander Scott Altman at the controls, close enough to capture Hubble shortly before 1700 GMT (1am on Thursday, Singapore time).
Astronaut Megan McArthur will reach out with the shuttle's robot arm to grapple the 11,110 kilogram telescope and carefully hoist it into Atlantis' cargo bay atop a rotating work platform that will serve as a workbench for spacewalking astronauts.
'I should not say this is nothing difficult,' said Tony Ceccacchi, Nasa's lead flight director for the mission. 'There are two vehicles going 17,000 miles per hour. But it's been done before, and we have high confidence in successfully completing it.'
Hubble circles the Earth at 560 kilometres, high above the distorting influences of the atmosphere. The high velocities of the shuttle and telescope keep the forces of gravity from tugging the two spacecraft out of orbit.
The space telescope, a cooperative project between Nasa and the European Space Agency, has been refurbished four times since its launch in 1990. The two space agencies believe a final overhaul will extend operations at least five years, long enough to finish the development and launch a more capable successor, the James Webb Space Telescope.
With Hubble securely aboard Atlantis, astronauts will use cameras on the robot arm to examine the telescope. The observatory may have aged dramatically since 2002, succombing to the corrosive forces of solar radiation, Nasa warned.
The first of five daily spacewalks to upgrade the observatory is scheduled to get under way on Thursday at 1216 GMT (8.16pm Singapore time). The excursion will pair astronauts John Grunsfeld, a 50-year-old astronomer who is making his third trip to Hubble, and Drew Feustel, a 43-year-old geologist on his first space mission.
Meanwhile, mission managers intend to complete an evaluation of damage to heat shielding tiles under the forward region of the right wing on Wednesday. The damage was found during a 10-hour inspection of the shuttle's heat shielding the previous day.
The inspection by the astronauts using cameras and lasers attached to an inspection boom on the robot arm revealed a string of gouges, stretching 53 centimetres across four heat shielding tiles beneath the forward edge of the wing near the fuselage. -- AFP
