CAPE CANAVERAL (Florida) - NASA scientists were on Tuesday assessing damage found on the underside of the Atlantis space shuttle, as it raced towards a risky space rendezvous with the Hubble telescope.

During a marathon 10-hour survey of fragile heatshielding on Tuesday, the seven-strong Atlantis crew found some damage to the underside of the shuttle's right wing.

RISKY MISSION The damage to the underside of the Atlantis may have occurred about 103 seconds into the shuttle's climb to orbit, the time at which a sensor in the right wing recorded an impact, shuttle communicator Dan Burbank said. A camera positioned on the underside of Atlantis and aimed at the shuttle's external fuel tank may have recorded the source of the impact debris. ... more

Nasa initially characterized the damage, which will undergo at least two days of evaluation by imagery experts in Mission Control, as minor. But it may warrant a second look on Friday with cameras and lasers fitted to the tip of an inspection boom fitted to the end of the shuttle's robot arm.

'The damage to me looked very small, but I'm not an expert,' Nasa's Tony Ceccacci, the lead flight director, told a news briefing. 'We will let those folks take a look at it.' The astronauts found a 53-centimetre long scrape extending across four heat shielding tiles on the underside of the forward portion of the right wing.

'The preliminary assessment is that it does not look too serious,' shuttle communicator Dan Burbank told Atlantis commander Scott Altman from Mission Control.

Atlantis lifted off with seven astronauts on Monday, initiating an 11-day day mission to overhaul the 19-year-old Hubble Space Telescope, equipping the observatory to carry on operations for at least another five years.

The shuttle crew was on course to rendezvous with the 560-kilometre high observatory on Wednesday shortly after noon.

In what will be a nail-biting operation, Altman will steer his ship close to the observatory, as astronaut Megan McArthur reaches out with the shuttle's robot arm to grab the 13.2 meter long telescope.

With the observatory in the arm's grasp, McArthur will mount the telescope upright atop a circular platform in the shuttle's cargo bay, establishing the work site for the overhaul.

The first of five daily spacewalks by the astronauts to upgrade the observatory will get under way Thursday. -- AFP