Appearing before the House Science Committee Oct. 29, retired U.S. Navy Adm. Harold Gehman, the chairman of the now disbanded Columbia Accident Investigation Board, said NASA handled appropriately objections by two agency doctors about launching a new crew to the station in mid-October, but attributed the agency's proactive response to heightened post-accident vigilance.

"The dissenting opinions were encouraged, followed up on, [and] taken seriously," Gehman said, but only because of the "good graces and cooperative attitude of managment" in the wake of the Columbia disaster.

NASA's history would suggest, Gehman said, that the openess to dissent and heightened vigilance will wane over time absent organizational changes at NASA.

"A year from now or 18 months from now, when cost and schedule pressures have resumed, I don't think we want to rely upon the intervention of management to snatch victory from the jaws of defeat,"  Gehman said. "I think we want to institutionalize a process by which these issues can be raised or sorted out without having top-level management to intervene."

NASA signed off on the launch of a new two person crew to the international space station Oct. 18 despite the objections from to agency doctors concerned about the "continued degradation" of environmental monitoring and health maintenance systems and exercise equipment. The two disenters, Nitza Cintron, NASA's chief of space medicine, and William Langdoc, chief of the Habitability and Environmental Factors Office, would not sign off on the launch of the Expedition 8 crew to the station and instead added their formal objection to the flight readiness document. NASA officials went ahead with the flight after vetting the two doctors' concerns and making some changes to the flight to address them.

But Gehman said absent systemic changes at NASA, there is no guarantee that such responsiveness can be counted on once the space agency gets back to flying the space shuttle.

"It took the active intervention of management to bring this issue to the program level," Gehman said. "It ought to come up automatically."

Gehman appeared at the tail end of a hearing devoted to taking testimony from a representatives of safety organizations identified as exemplary in the Columbia Accident Investigation Board's final report.

Across Capital Hill, NASA's human space flight chief, William Readdy, told a Senate panel probing the international space station program, that he was completely comfortable with the way the agency handled the Expedition 8 launch decision.

We have learned," Readdy told the two senior members of the Senate Commerce science, technology and space subcommittee. "Our process worked. There was open dissent, debate and resolution."