Grim details of Columbia disaster

The space shuttle disintegrated as it re-entered Earth's atmosphere

Nasa has released a detailed report into what happened to the space shuttle Columbia and its crew.

It comes almost six years after the orbiter disintegrated when re-entering the Earth's atmosphere.

The report includes grim details of the crew's final moments as the shuttle broke up over the state of Texas.

It also concluded that the astronaut's seat restraints, suits and helmets did not work well, leading to "lethal trauma".

"This report confirms that although the valiant Columbia crew tried every possible way to maintain control of their vehicle, the accident was not ultimately survivable," said Nasa's deputy associate administrator, Wayne Hale.

The accident happened on 1 February 2003.

Forty-one seconds

When the space shuttle Columbia blasted off from Cape Canaveral in Florida, the orbiter's left wing was damaged by a piece of insulating foam.

COLUMBIA'S FATAL FOAM Piece of insulating foam falls during launch, piercing one of shuttle's wings On re-entry, hot atmospheric gases blast inside the breach and melt ship's structure Crew cabin breaks away from ship and starts spinning rapidly Astronauts try to regain control of craft, flipping cockpit switches as alarms sound Rapid depressurization causes crew to lose consciousness Lack of safety restraints cause crew traumatic injuries

That proved fatal for the seven astronauts when they re-entered the Earth's atmosphere days later, says the BBC's Andy Gallacher in Washington.

The world watched as the shuttle disintegrated, its vital heat shield pierced by hot gasses, and its crew lost.

Nasa's extensive 400-page report into their last moments found that the crew knew for as long as 41 seconds that they did not have control of the orbiter before, investigators think, they were knocked unconscious.

Nasa also found that the astronauts did not have the necessary training that may have increased their chances of survival.

The tragedy happened on the 28th mission for Columbia and the report is thought to be the most comprehensive investigation into a shuttle incident ever carried out.

Mr Hale, who oversaw the shuttle programme during its return to flight after the accident, urged spacecraft designers in the US and overseas to read the report and apply the "hard lessons which have been paid for so dearly".