NASA spaceshuttle officials disputed claims Friday that the space agency had relaxed acceptablerisk standards while building toward its first orbiter launch since the Columbiadisaster.
"We're not doinganything that moves the risk or tries to hide the risk, or takes it to anunacceptable level," said Wayne Hale, NASA's deputy shuttle program manager,during a teleconference with reporters. "We're sharpening the pencil on how wedo our [risk] calculations."
Hale'scomments came in response to a New York Times reportthat suggested the agency had loosened its risk standards in order to meet thenew flight safety protocols instituted in the wake of the Columbia accident.
The report,citing internal documents forwarded to Times reporters, indicated that NASA hadchanged at least some of the statistical methods used to understand the risksof ice, foam insulation or other launch debris impacts. The report alsosuggested that lesser risk standards were required because NASA could not meettraditional standards for its first post-Columbia launch.
"Everything we're doing is consistent with how we approachrisk and safety elsewhere in the program," said John Muratore, NASA's managerfor shuttle systems engineering and integration, during the teleconference."We're not changing the way we calculate risk."
Some of thedocuments referenced by the Times were written in part by Muratore, thenewspaper reported.
Returning to flight
NASA'sthree remaining shuttles were grounded following the loss of the Columbiaorbiter, which was destroyed - and its seven-astronaut crew killed - duringreentry on Feb. 1, 2003. Hot gases, investigators later concluded, had penetrated Columbia's left wing through ahole gouged into its heat-resistant skin weeks earlier at launch by a1.67-pound, briefcase-sized chunk of foam insulation from the shuttle'sexternal fuel tank.
Since then,NASA shuttle managers and engineers have worked to revamp the agency's orbiterlaunch system in order to minimize risk and increase safety for futureastronaut crews.
"This is a risky business," Muratore said of humanspaceflight. "But we have done a tremendous amount to mitigate that risk...and thereare still some improvements we could put in over time."
NASA'sfirst post-Columbia accident mission, STS-114 aboard the Discovery shuttle, isslated to launchno earlier than May 22. In addition to testing a new orbiter inspection boomand repair methods for patching thermal protection tiles andreinforced-carbon-carbon panels, the mission will deliver vital supplies to theInternational Space Station (ISS).
Hale saidthat he was particularly disheartened that the engineers who sent the internaldocuments to Times did not go through NASA channels, and that they feared retribution.
NASA'sinternal culture was found partly at fault for the loss of Columbia because ofan apparent feeling that dissenting opinions were frowned upon or punished. Theagency has attempted to institute a culture change alongside its return toflight efforts.
"It bothersme that somebody felt they couldn't come up to us during a meeting," Hale said.
Hale addedthat while the bulk of the Times report was balanced, he took issue with astatement by Paul A. Czysz, emeritus professor of aerospace engineering at St.Louis University, who told the Times he was "amazed at how they were adjustingevery test to come out right."
"I findthat personally offensive," Hale said. "We're doing our best to find out what thetruth is. We're not adjusting our results, though there is some debate aboutwhat they mean."
More analysis is still needed before Discovery will be completely cleared for a May 22 liftoff, but NASA officals were confident they would be concluded.
"If I didn't think we were going to come to a conclusion, I don't think we'd be announcing launch dates," Hale said.
FixingNASA: Complete Coverage of Space Shuttle Return to Flight