Columbia Space Shuttle

Severed foam insulation was not considered a hazard even though it broke off during a shuttle launch a few months before Columbia's doomed flight, a NASA expert said at a hearing into the accident. James Halsell, an astronaut and launch manager, told the accident investigation board that the October incident on the Atlantis mission did not appear to be a reason to halt shuttle flights. On this and earlier launches, foam had not struck sensitive parts of the shuttle.

After analyzing shuttle debris and new data from sensors aboard the Columbia during its ill-fated return to Earth on Feb. 1, investigators say they can now almost pinpoint where superheated gases entered the space shuttle's left wing. "We are within 30 inches of knowing where the actual breach occurred," Roger Tetrault, a member of the Columbia Accident Investigation Board, said Tuesday.

Members of the Columbia Accident Investigation Board leaned even further Tuesday toward a theory that the leading edge of the orbiter's left wing was breached, allowing superheated gases to pass into its interior. The investigators are inclined to explain that breach by pointing to foam debris that fell from the shuttle booster's external tank upon liftoff and hit somewhere in the area of the left wing. When they issue their findings about the Feb.

Columbia accident investigators located a key data recorder in a debris field Wednesday. Officials hope they will find information about the space shuttle's final two hours of flight before the orbiter was destroyed. The device was found by a crew near Hemphill, Texas, during an effort to search nearly 500 square miles of the state. "This is the one we really wanted to get our hands on," said Laura Brown, spokeswoman for the Columbia Accident Investigation Board.

Before NASA can fly space shuttles again, it will likely have to give astronauts a way to repair damaged heat-protective tiles in orbit, restrict future flights to the international space station and replace its outdated ground computers, Columbia investigators said Tuesday. Limiting flights only to the space station could allow astronauts to carefully inspect the orbiter for damage during each flight and then make critical repairs to any damaged tiles before returning to Earth, said Steven B.

Civilian members of the board investigating the Columbia disaster have been put on NASA's payroll so the panel can use government secrecy rules to withhold testimony about the accident. Members of the House Space subcommittee, which oversees NASA, said making federal workers of the five civilian members undermines the board's independence and credibility. "It baffles me why they are doing this," said Rep. Bart Gordon (D-Tenn.).

Columbia investigators obtained their first direct evidence that foam debris caused the space shuttle accident after a foam block fired at a wing panel left a 3-inch crack in a test Friday. Engineers used a powerful gas gun to shoot a 1.6-pound block of foam at a replica of Columbia's left wing, damaging the delicate heat shield on the leading edge. Such damage may explain how a breach opened, allowing superheated gases to enter the wing and melt the aluminum structure.

Burnt toast, a truck mud flap, a Chevrolet alternator -- authorities collecting Columbia wreckage across what may be the world's largest accident scene are getting lots of calls about ordinary junk. "It's easy to speculate. It's easy to be confused," NASA spaceflight office deputy Michael Kostelnik said. Since Saturday's tragedy, NASA has collected thousands of pieces of space shuttle wreckage.

NASA investigators said Monday they now suspect Columbia's heat-resistant tiles might have begun falling off early in its descent, leading them to question whether they failed to recognize the damage caused when a piece of foam insulation struck the craft's left wing during liftoff.

Bowing to bipartisan congressional pressure, NASA's administrator agreed Wednesday to take further steps to ensure the independence of a blue-ribbon panel formed to investigate the breakup of the shuttle Columbia. Republicans joined Democrats in urging Administrator Sean O'Keefe to extend the current 60-day timetable for the panel's report on the Feb. 1 accident and to revise its marching orders to guarantee that the president and Congress receive findings directly.