CAPE CANAVERAL, Fla. -- Shuttle Discovery will remain grounded until at least Feb. 3 while NASA engineers continue to look for the cause of cracks in its external fuel tank, a top NASA official announced Friday.
William Gerstenmaier, the agency's associate administrator for space operations, said engineers still don't know enough about the cracks to justify launching Discovery on what's scheduled to be its last mission before retirement.
Discovery had been initially scheduled to launch on Nov. 1. But during a check of the shuttle resulting from other technical difficulties, engineers found several cracks in both the fuel tank's insulating foam and the tank structure itself. The tank has since been repeatedly X-rayed, but a cause of the cracks has yet to be determined.
John Shannon, the shuttle's program manager, said engineers could discover no obvious reason for why the tank cracked, so managers decided to outfit it with special instruments, including optical sensors that can see the tank in three dimensions, to try to better understand the stresses when the tank is filled with supercold liquid hydrogen and oxygen.
"Unfortunately, we are not making the December launch window," he said.
The Orlando Sentinel had reported Thursday that a source said the launch would be delayed until February, but a NASA spokesman denied that a decision had been made.
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