Space junk 'may have hit Shuttle'

A small meteorite or piece of man-made space junk may have struck the Columbia shuttle while it was still in orbit causing it to crash on its return to earth, Nasa said today.

Even a tiny scrap of debris grazing the shuttle could have damaged thermal tiles just enough to start a chain reaction once it started re-entering the atmosphere, said Milt Heflin, the space agency’s flight director.

“Did we take some hit? That’s a possibility. Something was breached,” he told the Los Angeles Times.

His comments cast doubt on the lead theory that a 20-inch piece of foam insulation fell off the external tank during the January 16 blast off and damaged the protective tiles.

Nasa was warned nine years’ ago that the shuttle could fail catastrophically if debris hit the vulnerable underside of its wings during lift-off, it emerged yesterday.

The agency made changes in materials and flight rules to lessen the risk of debris breaking loose after learning of the risk, said Paul Fischbeck, an engineering professor at Carnegie Mellon University who conducted the 1994 analysis.

The tiles protect the shuttle against intense heat during reentry through the atmosphere.

But analysts are now suggesting that damage to the tiles may have been caused by a collision in space.

Nasa has had to adjust the flight path of shuttles at least eight times to avoid large pieces of debris, said William Ailor, president of Aerospace Corporation, a nonprofit group that studies orbital matter.

A speck of paint once chipped the windshield of the Challenger during a mission completed before it exploded in 1986.

If a piece of space debris such as a chunk from a satellite broke off while the Columbia was in orbit it may not shown up on engineers’ space maps “until it was too late“, he said.

“It could happen. It is a possibility. There is a lot of debris up there. We’ve been in space for 40 years.”

There are believed to be more than a million objects within 1,200 miles of the Earth’s surface.

They include tools left behind by astronauts after spacewalks, pieces of rocket motors and debris from defunct satellites that are in constant orbit.

There are also thousands of space pebbles, known as a micro-meteors, some of them smaller than the diameter of a strand of hair.

NASA completes a comprehensive analysis of the shuttle’s projected path before each mission in an attempt to ensure that it is not struck by debris.

The Air Force can to pinpoint the location of space junk that is just centimetres in diameter.

Many analysts believe if something hit the shuttle with enough force to bring it down the crew and Nasa control would have known instantly.

A recent study into the potential impact of space debris concluded that a piece of plastic the size of a walnut could tear a 5-inch-wide hole through aluminium.

“Everybody would know if the shuttle struck something,” one analyst told the LA Times. “It would be loud.”

Meanwhile, Nasa is investigating reports that shuttle debris has been found as far west as California and Arizona, material that would have come from the earliest stages of Columbia’s break-up.

The remains of Israeli astronaut Ilan Ramon, one of seven astronauts who died in the crash, have also been found among the wreckage. His body is being returned to Israel for burial.

Nasa said there were at least three reports of body parts found in rural Texas, including a skull, a charred torso, a thigh bone and a charred leg.