MONTREAL - A Canadian-made 3-D scanning system is inspecting a dent in space shuttle Endeavour's underbelly to determine whether extensive repair work will be needed to the craft's heat shield before a return to Earth next week.
The Laser Camera System, designed by Neptec, an Ottawa-based firm, is one of three cameras attached to a Canadian-made inspection boom that surveyed the heat shield on Sunday, focusing in particular on a small gouge that could require an additional spacewalk by astronauts to repair it.
NASA officials aren't sure yet whether the 7.6-centimetre dent will need fixing, but if so, Canadian astronaut Dave Williams might get the call to do the patch job. Depending on the extent of the damage, astronauts can apply protective paint, screw on a shielding panel or squirt in filler goo.
Following a review into the Columbia shuttle explosion in 2003, NASA made it mandatory to have a way of imaging the entire thermal protection system, including making accurate 3-D models of any damage.
The shuttle Columbia was destroyed when hot atmospheric gases seeped into a hole in its wing and melted the wing from the inside out. A foam strike at liftoff caused the gash.
While it is referred to as a camera, the tool provides a real measurement of the damage and the surrounding tiles to an accuracy of less than a millimetre and not simply an image that is interpreted on Earth.
The tool uses a laser beam to go across a target in a scan pattern. The points are then put together on a grid that creates a 3-D image. The system is attached to a boom that is connected to the Canadarm aboard the shuttle.
"It basically makes a map of whatever it sees,'' Neptec president Iain Christie said in a telephone interview. "It gives NASA an exact full-scale rendition of what the damage looks like.''
The gash was caused by a grapefruit-sized piece of foam that came off the shuttle's external fuel tank during liftoff last week, striking tiles that insulate the ship from the intense heat of re-entry to Earth, NASA said.
A version of Neptec's 3-D system originally flew on a test flight in 2001 and has flown six times post-Columbia, but it has rarely needed to be used until now.
"We usually say that our fondest hope is that we have a boring flight and we don't have any work to do which has been the case for most of the previous flights,'' Christie said.
