Two and a half years after the catastrophic breakup of the shuttle Columbia, NASA's shuttle program roared back into space with the July 26 launch of Discovery. But faulty sensors, falling foam, and dangling insulation have raised concern for the safety of Discovery's astronauts and sparked worries for the space program's future.
After a week's delay caused by a fuel-system sensor error, Discovery embarked on a mission to the International Space Station. Shortly after takeoff, a 0.9-pound chunk of foam insulation broke off the side of the shuttle's external fuel tank but didn't appear to hit the shuttle. In February 2003, a slightly larger block of errant foam damaged Columbia's left wing during