Using a robotic arm, astronauts are now scrutinising a gouge on the shuttle's underbelly with a camera and laser attached to a boom.
The location and size gives engineers some confidence that the damage is not the type that caused the disintegration of the space shuttle Columbia in 2003. They also note that similar damage on Endeavour in 2007 - coincidentally commanded by Scott Kelly, brother of current commander Mark Kelly - turned out not to be a problem.
LeRoy Cain, chairman of the shuttle mission management team that decided to order what's called a 'focused inspection', said the operation was being conducted out of an abundance of caution and will not cause any disruption to the crew or its 16-day mission to the International Space Station.
The damaged tile was spotted in photos snapped by the station crew just before the shuttle linked up on Wednesday. Initially, the photos showed seven sites with dings or gouges, but six of them were further analysed and turned out not to be a problem.
The one site that remains a concern is the size of a deck of cards, just below the rear landing gear, but Cain said it is so unlikely that the gouge will be problematic that Nasa is not even considering a plan to fix the tile in flight. NASA can repair damaged tiles using a souped-up version of a caulking gun during a spacewalk.
'There's nothing alarming here and we're not really concerned,' Cain said. Read More