Washington, June 13: investigators today said they discovered a dangerous new threat to America's remaining three space shuttles, a fault affecting the heavy bolts that connect the powerful solid-rocket boosters to the external fuel tanks. The Columbia accident investigation board, studying the fiery breakup of the Feb. 1 shuttle flight over the southwestern United States, said it worried that parts of these 40-pound, 2-foot-long bolts could break free shortly after liftoff and smash against delicate areas on spacecraft during future missions. Board officials said the fault involves a "bolt catcher," a container mounted on the fuel tank designed to capture fragments of the attachment bolts immediately after astronauts jettison the powerful booster rockets about 45 kms into their ascent. Retired Navy Adm. Harold Gehman, the head of the board, said investigators have determined that the bolt catcher was "not as robust as we would want."

Air Force Maj. General John Barry, a board member, indicated the flaw could delay NASA's next shuttle launch.
"This is a possible return-to-flight issue," said Barry, calling the bolts a "pretty heavy piece of machinery."
The 150-foot-tall rockets are mounted on either side of a shuttle's external fuel tank and help provide nearly all the tremendous thrust needed to enter orbit. They are designed to fall away safely into the ocean for later recovery by NASA.

Board members said they do not believe the breakaway bolts - which use explosive devices during the jettison to break the attachment - contributed to the Columbia disaster, but expressed concern that bolts could cause similar fatal damage to another shuttle's panels on future missions. Bureau Report