The astronauts on the shuttle Columbia tried to control the spacecraft as it broke up over Texas on its way back from a 16-day mission on February 1, 2003, but they had no chance of surviving, NASA says in a sobering report.

All seven crew members were killed when the craft split apart from damage the left wing suffered after a huge chunk of insulating foam from the shuttle’s external tank broke off during its launch.

At least one crew member tried to reset the shuttle’s autopilot and had flipped cockpit switches as alarms sounded on board, according to the report released yesterday. But all of the astronauts lost consciousness within seconds as the spacecraft depressurized and spiraled out of control.

"We have evidence from some of the switch positions that the crew was trying very hard to regain control. We're talking about a very brief time in a crisis situation," NASA's deputy associate administrator, Wayne Hale, said at a press conference yesterday.

The astronauts were wearing pressurized space suits, but apparently didn't have time to activate them. The depressurization in the cabin “occurred so rapidly that the crew members were incapacitated within seconds, before they could configure the suit for full protection from loss of cabin pressure,” the report says. “The effects of the depressurization were severe enough that the crew could not have regained consciousness. This event was lethal to the crew.”

Flaws in other equipment also contributed to the astronauts’ deaths, NASA says. Their shoulder harnesses didn’t lock, and their helmets didn’t conform to their heads. So as the orbiter spun out of control, its cyclical rotation rocked them violently about, causing traumatic injuries.

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

The report recommends improvements to crew training and equipment design, but extreme weather in the upper atmosphere, including thermal conditions and strong winds, still would have been enough to kill the Columbia crew, the report adds. “The only known complete protection from this event," it says, "would be to prevent its occurrence.”

Image of Columbia crew/NASA. Top row, from left: David M. Brown, William C. McCool, Michael P. Anderson. Bottom row, from left: Kalpana Chawla, Rick D. Husband, Laurel B. Clark and Ilan Ramon.