NASA probing mishap, damage to shuttle fuel tank

CAPE CANAVERAL, Fla., Mar 30 (Reuters) NASA is investigating another mishap at the Kennedy Space Center, this time an accident involving the remodeled fuel tank to be used for the next shuttle mission, the agency said.

Technicians were replacing a vent valve near the top of the 154-foot (47-metre) tall tank on Tuesday when a Halogen work lamp fell and hit the tank's foam insulation.

Preliminary inspections show the impact left five small indentations, with the largest about the size of a stick of gum, and one 6-inch (15-cm) to 7-inch (17-cm) long scratch, said Marion LaNasa, spokesman for tank manufacturer Lockheed Martin Corp.

A detailed inspection of the area was under way, LaNasa said, but the incident was not expected to affect the shuttle's targeted July 1 liftoff.

The affected area is not among the sections of tank foam nsulation that were redesigned after the 2003 Columbia disaster and again after the July 2005 flight of Discovery, the only launch since the accident.

A piece of foam insulation that fell off the tank and hit Columbia's wing during liftoff was responsible for heat shield damage that led to the ship's destruction and the loss of seven crewmembers during atmospheric re-entry on Feb. 1, 2003. A similar problem occurred during Discovery's liftoff 2-1/2 years later, though the shuttle escaped damage.

NASA is preparing Discovery for launch again, but it first must prove that the new tank design is safe to fly. A series of wind tunnel tests and analyses are under way.

Safety has been a top priority for NASA, particularly at the shuttle processing center in Florida, where a series of mishaps have resulted in a death, equipment damage and several near-disasters over the past month.

REUTERS SK RN0421