- The Washington Times - Tuesday, June 24, 2003

Accident investigators examining the disintegration of the Space Shuttle Columbia said more forcefully yesterday that foam insulation had shed from the orbiter’s external fuel tank and pierced its left wing.

Investigators also said they will recommend that the National Aeronautics and Space Administration find better ways to guard against damage to thermal protection tiles from foam.

“What is the most probable cause? We believe the foam is the most probable cause,” said Roger Tetrault, a member of the Columbia Accident Investigation Board.

Mr. Tetrault said evidence from shuttle debris recovered in Texas and Louisiana, and engineering data from the flight data recorder point to a hole measuring 6 to 10 inches in diameter in the eighth panel on the leading edge of Columbia’s left wing.

Mr. Tetrault also said Columbia flew about 100 miles with just half of its left wing.

Columbia disintegrated Feb. 1, killing seven astronauts.

Over Texas, “a portion of the left wing came off.”

“A portion of the left wing continued to ride with the aircraft … and at some point later on [the remaining panels] began to come off the aircraft,” he said. “The pieces were just open to the airstream and were falling off.”

Each wing has 25 carbon panels lining its leading edge.

Investigators also said yesterday that preliminary recommendations that are likely to be issued this week will instruct NASA to find ways to bolster safety by reducing the likelihood that foam sheds from each shuttle’s external tank.

Tests by investigators at the Southwest Research Institute earlier this month proved that foam can damage the panels. Investigators discovered that foam came off external fuel tanks and caused significant damage to shuttles eight times.

“We’re trying to look forward and address overall mission safety by seeing whatever can be done to reduce the likelihood of failures that we believe caused this accident or may have caused this accident … that we’ve identified that could potentially create hazards,” accident investigation board member Steve Wallace said.

In addition to reducing the likelihood of failures, investigators will ask NASA to either strengthen the tiles on its three remaining shuttles, which remain grounded, or find a way for astronauts to repair damaged tiles during a mission.

Tile repair probably would be done while shuttles were docked at the International Space Station.

Most upcoming shuttle flights are bound for the space station, Mr. Wallace said.

Foam insulation isn’t the only item posing a threat to the shuttles. Two weeks ago, investigators said 40-pound explosive bolts used to separate the shuttle’s solid rocket booster could spring loose and slam into a shuttle. There is no evidence that Columbia was damaged by the bolts.

The interim recommendations will come as no surprise to NASA, Mr. Wallace said.

Investigators have issued preliminary recommendations just one other time. Their final report is likely to be finished late next month.

The difficulty is issuing a recommendation that NASA can carry out, said Harold W. Gehman, chairman of the 13-member investigation board.

“The board is struggling with how specific to be, with how demanding to be. We’re being very careful with the words,” Mr. Gehman said.

Mr. Gehman said half the final report will cover management issues. He also said the report will urge NASA to speed up development of the shuttle’s replacement vehicle. Too many times, he said, NASA has trashed plans for the shuttle’s replacement.

Mr. Gehman also said NASA should be able to resume shuttle flight in six to nine months.

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