Shuttle disaster probe explores tyre blast

Just two days before space shuttle Columbia8217;s mysterious breakup during its fiery descent, a safety engineer warned by e-mail about ris...

Just two days before space shuttle Columbia8217;s mysterious breakup during its fiery descent, a safety engineer warned by e-mail about risks of 8216;8216;catastrophic8217;8217; failures from extreme heat causing the shuttle8217;s tyres to burst inside the spacecraft, NASA disclosed.

Separately, searchers near Hemphill, Texas, about 225 km northeast of Houston, said yesterday they recovered what they believed to be one of Columbia8217;s tyres. It sustained a massive split across its tread, but it was impossible from photographs to know whether the tyre was damaged aboard Columbia or when it struck the ground.

Engineer Robert H. Daugherty, responding to a query from Johnson Space Center, cautioned NASA colleagues in strident language that damage to delicate insulating tiles near Columbia8217;s landing gear door could cause one or more tyres to burst, perhaps ending with catastrophic failures that would place the seven astronauts 8216;8216;in a world of hurt.8217;8217;

Such a blast in Columbia8217;s belly, Daugherty predicted, could blow out the gear door and expose the shuttle8217;s unprotected innards to searing temperatures as it raced through the atmosphere. Bailing out would be 8216;8216;not a good day,8217;8217; he wrote. But attempting to fly the shuttle with only one side8217;s landing gear lowered would be worse: 8216;8216;You8217;re finished.8217;8217;

Daugherty acknowledged in his e-mail that these were 8216;8216;absolute worst-case scenarios8217;8217; but defended them: 8216;8216;you should seriously consider the possibility of the gear not deploying at all if there is a substantial breach of the wheel well.8217;8217; He referred questions about his concerns to a NASA spokesman. Officials said they didn8217;t want reporters to speak to Daugherty as he was not questioned by accident investigators. NASA disclosed the contents of his e-mail yesterday.

The e-mail from Daugherty, an engineer at NASA8217;s Langley Research Facility in Hampton, Virginia, was prompted by a call on January 27 from Johnson Space Center who asked what might happen if Columbia8217;s tyres were not inflated when it tried to land.

Meanwhile, space shuttle debris arrived at Florida8217;s Kennedy Space Center. Two trucks arrived about 9 am with some 15,000 pieces of debris. Members of the independent investigation board led by retired Admiral Harold Gehman also arrived.