Report Likely to Say NASA Minimized Foam Peril

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.

In addition, investigators have determined that particularly large pieces of foam called bipod ramps, which cover the spot where the orbiter is attached to the tank, have fallen off on at least seven flights. It was a foam bipod ramp, weighing 1.67 pounds, that rammed the Columbia’s leading edge and probably opened a hole in the wing’s reinforced carbon carbon.

Until this year, no bipod ramp had ever struck an orbiter’s wing, though last October one hit a solid rocket booster. The incident led NASA to start an investigation, but the team’s report was delayed beyond the launch of Columbia on Jan. 16. Shuttle managers never considered stopping the launches to study the issue.

Indeed, Marshall managers defended their tank at the preflight review for the Columbia mission, insisting that it was safe to fly, despite the October flight problem. “The external tank is safe to fly with no new concerns and no added risk,” according to a briefing given by Marshall engineers to top NASA officials on Oct. 31.

As disclosures about NASA’s handling of the foam problem came out this spring, accident investigator Steven Wallace termed the agency’s mind-set as “success-based optimism.”

The fallacy of that optimism was revealed by aerospace experts in the aftermath of the accident. NASA had never conducted tests to establish how large a foam strike could occur without damaging the orbiter, according to Aloysius Casey, a retired Air Force general who had spent a career in space engineering. “A series of successful flights does not verify a [safety] margin,” Casey said. “You may be skating the very edge.”

Although such observations may now seem obvious, Columbia investigators say they never found any expert who raised red flags about the foam. But 17 years ago, a vague prediction of the Columbia accident was made during the investigation of the Challenger accident.

At a hearing by the Rogers Commission, which investigated Challenger, former NASA shuttle director Arnold Aldridge testified that engineers for Rockwell International had warned about the potential for foam debris damaging the thermal protection system.

“There are quite large pieces,” Aldridge testified. “A half-foot square or a foot by a half-foot ... fairly high up on the tank. So they had a good shot at hitting the underbelly, and that is where we had the damage.”

Aldridge said he had rejected the concerns expressed by Rockwell, which built the shuttle, because of the company’s conservatism. He recounted the story to demonstrate why he felt justified in also rejecting Rockwell’s advice against launching the Challenger on the morning it blew up.

It wasn’t the first time that officials at Rockwell, which was later acquired by Boeing Co., warned about the serious problems with foam debris, according to former company engineer Allen J. Richardson.

Richardson said in a recent interview that during the early 1980s he had designed a complex set of evaluation tools, known as the crater program, that had predicted large pieces of foam debris hitting the leading edge could be “catastrophic.” Since the accident, investigators have criticized the program as an inadequate diagnostic tool -- one that incorrectly predicted Columbia’s safe return.

Richardson rejected that criticism and said the crater program was sophisticated enough to predict the consequences of the foam strike against Columbia. He said he provided private testimony to Columbia investigators this year and is waiting to see whether the report unveils the truth about the foam problem.

When Columbia was launched Jan. 16, high-speed cameras on the Florida coast recorded the foam bipod ramp detaching from the external tank and slamming into the orbiter’s left wing about 82 seconds after liftoff.

Within two days, engineers had calculated that the foam debris was the largest they had encountered and that it struck the orbiter at more than 500 mph. News about the foam spread rapidly within the NASA engineering community and set off rounds of e-mail exchanges among experts who speculated that it could be a serious safety problem.

Within two days of the launch, a 37-member team was assembled to examine the foam debris, consisting of representatives from three NASA research centers and engineers from Boeing, Lockheed Martin Corp. and United Space Alliance.

One early recommendation called for NASA to ask the Defense Department or intelligence agencies to take photographs of the orbiter with spy cameras to assess potential damage.

The recommendation went to Linda Ham, the mission chief for Columbia at the Johnson Space Center, but she since has told reporters that she mistakenly thought it was coming from NASA engineers far removed from the shuttle program. The request was rejected. At the time, Ham said nothing could be done if the Columbia was damaged. That explanation continues to baffle investigators.

“I cannot understand why NASA management would have prevented those images from being obtained,” Douglas Osheroff, an accident board member and Nobel Prize-winning physicist at Stanford University, said in an interview. “It doesn’t make sense.”

Since the accident, NASA officials have strongly denied that they suppressed dissent and said they always valued safety above everything else in the program.

Investigators and critics agree that the agency was never intentionally careless or negligent, but that it was unable to recognize its own failings.

Samuel Culbert, a UCLA expert in clinical psychology and systems engineering, said that NASA’s communication breakdown reflects many mistakes common in large organizations.

Culbert said the appointment of a special debris team was asking for trouble, because typically such “red teams” or “tiger teams” lack accountability and are led by a chairman who lacks authority.

“You can’t hold anybody accountable when they don’t have responsibility,” he said. “Red teams don’t have anybody in charge.”

Indeed, NASA’s debris analysis team was headed by Rodney Rocha, a Johnson engineer who has said that he felt so junior in the shuttle program that his superiors were not listening to his recommendation and he could not talk to them directly.

Rocha was supposed to report his findings not to a single individual but to the “mission evaluation room,” something like an operations center, according to a NASA spokesman.

“The room? Well, which wall in the room was he supposed to report to?” Culbert asked. “This is not rational.”

In frustration, Rocha wrote a memo during the Columbia mission that NASA’s decision to not seek photographs bordered on irresponsibility and that the foam debris represented a grave hazard to the crew. The memo went to his supervisor but apparently never reached Ham, the person in charge of the mission.

As accident board chairman Harold Gehman Jr. put it: “The people who had doubts about anything were essentially outside the circle and had to work their way in, rather than the doubters being inside the circle.”

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Times staff writer Peter Pae contributed to this report.