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Report Likely to Say NASA Minimized Foam Peril

August 26, 2003|Ralph Vartabedian | Times Staff Writer

After an 18-day mission more notable for its technical failures than anything else, the space shuttle Columbia returned to Earth on Dec. 7, 1996, carrying another unpleasant surprise for NASA officials.

Ground crews inspecting Columbia's underbelly found 244 potholes, gouges and dimples in its delicate thermal protection system -- some of the worst damage ever noted on a returning shuttle.

NASA officials blamed foam debris that fell off the shuttle's external tank for the damage. But those officials -- as well as the astronauts whose lives were on the line -- did not recognize the debris as a threat to the safety of the people aboard.

Now, a report is due out today that investigators say will cite the falling foam -- and the space agency culture that underestimated the danger posed by it -- as the cause of February's space shuttle disaster.

"In hindsight, we should have looked at it and said, 'Jeez, this is really serious,' " astronaut Winston Scott said in a recent interview. "I didn't realize then that it could have had catastrophic ramifications. We got back safely and we figured it was somebody else's job to take care of it. I should have been more alarmed."

Another astronaut who flew with Scott on that 1996 mission would never have the opportunity for hindsight: Kalpana Chawla, who died along with six other crew members when the Columbia burned up over Texas during reentry.

Over the history of the shuttle program, NASA's top managers and some of its most brilliant engineers had come to accept the foam debris damage as a nuisance and a headache but not a threat to astronaut safety or the $2-billion orbiters.

Every shuttle that returned to the hangars at Kennedy Space Center since flights began in 1981 showed some kind of foam debris damage. On average, technicians found 30 dents and scrapes that had to be repaired on every mission.

And during the final Columbia mission, the lack of concern was so ingrained in NASA thinking that top managers dismissed the possibility that the orbiter was gravely damaged -- even though it had been struck by the largest piece of foam ever documented.

It is now believed that the foam opened a breach in the leading edge of the left wing, allowing hot gases to melt away its internal structure when Columbia returned to Earth on Feb. 1.

When the Columbia Accident Investigation Board issues its final report, it will take a hard look at the breakdown of NASA's safety culture that allowed the foam debris problem to fester.

The accident board's seven-month investigation has already made clear that the tragedy is the culmination of missteps and analytical failures stretching from the Columbia mission to the earliest days of the space shuttle.

"NASA has become incompetent to oversee the human spaceflight program," said Rep. Dana Rohrabacher (R-Huntington Beach), chairman of the House Aeronautics and Space Subcommittee. "What was once a government organization that shined has become a big blob of bureaucracy."

A major restructuring of America's space program is coming that will require the closure of at least one and perhaps two of NASA's major research centers, Rohrabacher said.

The seeds of the disaster go back to the 1970s, when design engineers specified that no debris should ever strike an orbiter's revolutionary thermal protection system. It consisted of delicate, lightweight tiles on most wing surfaces, and a more heat-resistant material called reinforced carbon carbon on the leading edges.

The foam, however, represented something of an afterthought, an attempt to make sure ice debris would not wound the orbiter, according to an October 2002 report issued by the Marshall Space Flight Center.

Ice would form on the tank, which was filled with liquid hydrogen and oxygen hundreds of degrees below zero, unless insulation was used on the tank skin. As matters turned out, the solution to the ice debris problem became the foam debris problem.

From the very first flight, some foam would not stick to the tank. And just as soon as the defects with the foam were recognized, NASA managers set aside their rule that nothing would be allowed to strike the orbiter during launch.

"All of the debris has been judged by the system as not a safety-of-flight issue," Lee Foster, an engineer at the Marshall center, said at an investigative hearing this spring. "Rightly or wrongly, they were all declared a maintenance item and not a safety-of-flight issue."

Of the 244 debris strikes that occurred on the 1996 Columbia mission, 109 left gouges larger than 1 inch. The largest measured 15 inches.

In 1988, the shuttle Atlantis was struck by more than 250 pieces of debris, the largest number ever.

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