Shuttle disaster was 'foreseen'

2003-02-13 16:20

Washington - Two days before the end of the United States space shuttle Columbia, a National Aeronautics and Space Administration engineer raised the possibility of a catastrophe caused by the overheating of landing gear.

This, he said, was likely to result in a potentially disastrous tire blowout while the spacecraft was re-entering the Earth's atmosphere.

In an internal memorandum dated January 30 and titled "Main Gear Breach concerns", which was made public late on Wednesday by Nasa, engineer Robert Daugherty considered the possibility that debris is believed to have damaged the left wing of Columbia during takeoff could have also seriously damaged the door of the wheel well.

Eighty seconds after Columbia's launch on January 16, a chunk of insulating foam separated from the central external fuel tank located under the belly of the shuttle. The foam struck protective tiles under Columbia's left wing.

Between January 20 and January 27, engineers held a series of meetings to evaluate the extent of the damage the debris might have done to the tiles.

Enormous outside temperatures

On January 28, flight managers concluded the impact had not hurt the shuttle to the point endangering its re-entry into the atmosphere.

But, two days later, Daugherty, whose opinion had been requested, shared his concern with the flight managers.

The foam, he explained, could have damaged the door of the wheel well, thus exposing the landing gear, made of aluminium, to enormous outside temperatures.

"The reason might be that ... the wheel (aluminium) will lose material properties as it heats up and the tire pressure will increase," he wrote.

"At some point, the wheel could fail and send debris everywhere."

Daugherty suggested the wheel might degrade in strength and burst.

"It seems to me that with that much carnage in the wheel well, something could get screwed up enough to prevent deployment (of the wheel), and there you are in a world of hurt," he pointed out, raising the possibility of the shuttle crash landing on its belly.

Candid remarks

Daugherty also suggested that overheating could set off small explosive charges designed to help deploy the landing gear in the event of it getting stuck, and damage other parts such as hydraulic systems.

David Lechner of United Space Alliance, a Nasa subcontractor, to whom the e-mail was addresses, gave the following response: "I really appreciate your candid remarks... Your input is beneficial.

"Like everyone, we hope the debris-impact analysis is correct and all this discussion is moot."

NASA did not make any comment as it released the document.

According to Nasa, the first anomalies leading to the shuttle's disintegration were reported in the wheel well as Columbia hurtled towards the Earth at a speed of more than 21 000km/h. - Sapa-AFP

- SAPA