Inquiry focuses on left wing of shuttle

INVESTIGATORS were last night focusing on Columbia’s left wing as they tried to determine what destroyed the space shuttle, killing all seven astronauts on board.

A piece of insulating foam broke off the external fuel tank about a minute into Columbia's launch on January 16, smashing into the wing, which is covered with thermal tiles to protect the ship from the extreme heat experienced on re-entry into the atmosphere.

Just a day earlier, NASA had given assurances that the incident was no reason for concern. The space agency did an extensive engineering analysis that included a frame-by-frame examination of the launch video, and concluded that any damage to Columbia's thermal tiles would be minor.

However, the independent commission appointed by NASA to investigate the catastrophe is now looking at the possibility that the tiles were damaged far more seriously than previously thought.

The same wing showed sensor failures yesterday, 23 minutes before Columbia was due to touch down.

Seven minutes later the shuttle disintegrated over Texas.

Shuttle manager Ron Dittemore said: "As we look at that now in hindsight ... we can't discount that there might be a connection. But we have to caution you and ourselves that we can't rush to judgement on it because there are a lot of things in this business that look like the smoking gun but turn out not even to be close."

He added that, even if the damage had been known, there was nothing that the astronauts could have done in orbit to fix damaged thermal tiles and nothing that flight controllers could have done to safely bring home the shuttle.

Columbia had been due to touch down in Florida at 2.16pm and was at an altitude of 200,700ft almost 40 miles up and travelling at 12,500mph when Mission Control lost contact with it.

Six of the crew were American, and the seventh was Israeli Ilan Ramon, a former pilot and air force colonel who was also his country's first astronaut.

Shuttle commander Rick Husband, a lieutenant colonel in the US Air Force, worked as an exchange pilot with the RAF at Boscombe Down, Wiltshire, England, in the 1980s.

The others were Indian-born mission specialist Kalpana Chawla, pilot William McCool, Michael Anderson, David Clark and Laurel Clark.

Their families were said to have been watching the disaster unfold live on television, as footage showed a bright light followed by plumes of white smoke plumes streaking diagonally across the sky. Debris appeared to break off into separate balls of light as it continued downward.

In north Texas, people reported hearing "a big bang" around the time all radio and data communication with the shuttle was lost.

Debris from the craft, which completed a 16-day scientific mission, was being recovered from Louisiana and the Dallas and Fort Worth areas of Texas.

Items found included a charred patch from an astronaut's suit and a flight helmet.

Investigators also took away a badly burnt human torso, skull and thigh bone found near other debris on a rural road in Hemphill, Texas.

US President W George Bush telephoned the astronauts' families before making a television address.

"The Columbia is lost," he said. "The same creator who names the stars also knows the names of the seven souls we mourn today. The crew of the shuttle Columbia did not return safely to Earth but we can pray they are safely home."

It was the second time in just four months that a piece of fuel-tank foam came off during a shuttle lift-off. In October, Atlantis lost a piece of foam that ended up striking the aft skirt of one of its solid-fuel booster rockets. At the time, the damage was thought to be superficial.

Mr Dittemore said this second occurrence "is certainly a signal to our team that something has changed".