Workers may have accidentally cut or crushed a section of foam that broke off during Discovery's launch. The section in question was on the fuel tank. That is the leading theory for the cause behind the disturbing loss of foam insulation that cast a cloud over NASA's return to space, said Wayne Hale, the newly appointed manager of the space shuttle program. To NASA's horror, a 1-pound, 3-foot chunk of insulating foam peeled away from Discovery's external fuel tank during liftoff in late July. In addition to the big chunk of foam, several smaller pieces broke off, including at least one from an area of the fuel tank that had been modified after Columbia. Thermal tile was also damaged on Discovery's belly; one tile lost a 1 1/2-inch piece right next to the set of doors for the nose landing gear, a particularly vulnerable spot.