Image: Photographing Discovery
NASA file
Technicians photograph the exterior of the shuttle Discovery during its April 6 journey to its Kennedy Space Center launch pad. The photo session was aimed at developing a database of imagery that can be compared with in-flight imagery, to check for potential damage.
By NBC News space analyst
Special to NBC News
updated 4/25/2005 11:32:17 AM ET 2005-04-25T15:32:17

Safety standards for the next space shuttle launch are not being relaxed through mathematical manipulation, NASA shuttle managers insisted Friday, in response to a New York Times article that cited internal agency reports to raise that possibility. The managers denied that they were trying to “cook the books” about safety tests in order to force a foregone conclusion.

Instead, they insisted that their teams were pulling together two years of exhaustive tests and analysis programs to provide NASA decision-makers with the information necessary to make the launch decision in early May. The shuttle Discovery is currently scheduled for launch no earlier than May 22.

The Times reported on Friday that NASA officials were loosening the standards “for what constitutes an acceptable risk of damage from the kind of debris that led to the disintegration of the shuttle Columbia.” It said there was strong debate within the agency over whether “long-established rules” were being jettisoned “to justify getting back to space quickly.”

In response to the Times' report, NASA made two of the NASA officials most extensively quoted in the article available to journalists Friday afternoon. Wayne Hale, deputy director of the space shuttle program, and John Muratore, the manager of systems engineering and integration for the shuttle program, talked by phone for more than an hour.

The Times had shown the NASA reports to Paul Czysz, professor emeritus of aerospace engineering at Saint Louis University. Czysz said the documents did not show that the shuttle was too dangerous to return to space, but he did tell the Times that he felt NASA had changed the statistical standards to get desired answers. "I was amazed at how they were adjusting every test to make it come out right," he told the newspaper.

Muratore rejected this interpretation of the safety process. “This is the most rigorous activity I’ve ever been involved with in my career at NASA,” he declared.

“We’re not doing anything that tries to hide the risk,” Hale added. While stating that he found the Times article “pretty balanced,” he said there were two aspects of it that caused him some distress.

One theme was that people who spoke with the newspaper still feared retribution for their views. “I found that disheartening,” Hale said.

Hale said he believes NASA leadership is seeking out dissenting viewpoints and responding rationally to them. “It bothers me that somebody felt they couldn’t come forward,” he added.

Hale also vehemently disagreed with Czysz’s claim that NASA officials were changing standards to force the data to support a desired outcome. “I find that personally offensive,” he told the journalists. “There will be no corners cut on my watch.”

Hale described his own feelings of shame over the mere appearance of his name as a witness in the report by the Columbia Accident Investigation Board. “I don’t want my name to ever again appear in any accident report,” he stated.

Muratore described the different mathematical approaches to risk assessment that different engineering subcultures used in their own areas of specialization, and how the techniques were being accommodated in the safety reviews. Some approaches used statistical analysis, and some relied on structural analysis and testing, he said. Others took a “systems viewpoint” and ran hundreds of randomized simulations to evaluate the uncertainties surrounding risk assessments.

“When it all came down to rate the risks,” he explained, “there was complete agreement on the level of the risk. Their different ways of assessing risk came up with answers that were essentially the same.”

Both NASA officials struggled for words to put what they called “an extremely complex process” into terms that might be familiar to the general public. “Like many other human activities, this is a messy business,” Hale said. Muratore added that “people are seeing it who aren’t used to looking at it.”

Hale likened the process to the proverb about watching sausages get made. When asked if in fact the “sausage” was now complete, he promised it soon would be. Muratore dismissed doubters with the comparison with “the family member who’s afraid to fly in airplanes.”

Another senior NASA manager with extensive shuttle experience, who exchanged e-mails with on the condition that his name not be used, called the Times' story “very well done and accurate,” as far as he understood the issues.

He confirmed that the internal safety presentations on the consequences of debris impact on the orbiter’s wings had concluded that the first tank did not meet the higher standards that considered the potential damage to the shuttle's brittle leading-edge panels. That first tank was prepared for flight using "largely heritage processes, with modifications to the high-risk areas," he noted.

At the same time, he continued, the substantial safety risk is a result of the overall shuttle design, not of any detailed mechanical adjustments that can reasonably be made.

“I think it is not unwise to return to flight,” he said in the e-mail, while adding that better safety standards would have to be built into the designs of follow-on human space vehicles.

As Muratore explained, different levels of reliability can justifiably be used for contingency events of differing original probability. For the issue of damage to the shuttle’s thermal protection system, the hazard level is eased by a reduction in the probability of debris coming off at launch — and by the equally significant development of recovery strategies, such as seeking “safe haven” aboard the space station, that would be used if damage does occur.

James Oberg, space analyst for NBC News, spent 22 years at the Johnson Space Center as a Mission Control operator and an orbital designer.


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