WASHINGTON — Documents pertaining to erosion of the seals joining the segments of solid rocket boosters on the space shuttle were delivered Monday to the presidential commission investigating the disastrous Challenger explosion.
Jesse W. Moore, the National Aeronautics and Space Administration official who heads the shuttle program, brought a 1 1/2-inch thick stack of documents to the commission for a private briefing.
"We're coming to respond to the commission and provide the information they asked for," Moore told reporters before moving quickly into the Old Executive Office Building adjacent to the White House.
Former Secretary of State William P. Rogers, chairman of the 13-member investigative panel, hastily arranged for the presentation after NASA documents raising questions about the quality of seals on the solid rocket boosters were published Sunday in the New York Times.
NASA officials concede that there was concern about evidence of erosion and charring on at least a dozen seals after shuttle flights, but they discount the impression created by one of the quoted memoranda that warnings of potential in-flight catastrophe were being ignored.
The performance of the seals, a combination of heavy synthetic rubber O-rings and flame-resistant putty, has become a focus of concern because their failure could allow extreme heat from the booster's burning rocket fuel to escape out the side of the booster and come into contact with the shuttle's giant external fuel tank--potentially causing an explosion.
A rupture of the Challenger's right-side rocket booster, visible in numerous photographs, is viewed as the most likely starting point in a catastrophic chain of events.
The commission was to hold a public session today, the second since it was formed by President Reagan eight days ago, and NASA officials were preparing to hold a rare briefing for reporters on their internal investigation of the tragedy.
Executive Director Named
Prior to the commission's closed session Monday, Rogers announced the selection of an executive director for the commission. He is Alton G. Keel Jr., who currently is associate director for national security and international affairs in the Office of Management and Budget.
Keel, 43, has a background in aerospace engineering and worked previously for the White Oak Laboratory, the Senate Armed Services Committee and the Air Force.
He told reporters that he intended to build a staff with enough expertise to independently evaluate material gathered by NASA officials. At present, NASA is in a position of investigating itself, as the President's commission must rely on the space agency's interpretation of data.
"Certainly, the commission isn't going to duplicate the work of NASA," Keel said. "We obviously are independent and are going to remain independent, as the President wants. The basic data-gathering is going to have to be done by NASA, but we will do our own analysis and review."
As salvage work aimed at retrieving key segments of the spacecraft from the sea floor pressed on with no reported success, NASA officials formally announced what had been evident since the Challenger explosion. They said that at least the next three scheduled shuttle flights, including missions that were to dispatch probes to Jupiter and the sun, have been officially postponed.
Meanwhile, yet another possible explanation of the Challenger disaster was offered Monday by Aviation Week and Space Technology. The industry magazine, providing no description of sources, said NASA investigators believe that a rupture of the Challenger's right solid rocket made the bottom of the booster pivot out from the external tank. This caused the tip of the rocket to butt the volatile fuel cylinder, and an explosion immediately ensued.
NASA sources said this could well be among avenues pursued by investigators, but they conceded that the question of how the final explosion occurred is in a sense moot: Once the booster developed its rupture, the spacecraft was doomed.
Jim Mizell, a former NASA engineer who now works in the public affairs branch of the Kennedy Space Center in Florida, said that all theories about how the external tank exploded start with a rupture of the adjoining right-side rocket booster.
"There's at least half a dozen scenarios," he said. "I think the ultimate outcome (of any of them) is what you saw (the explosion)."
Staff writer Kim Murphy contributed to this report from the Kennedy Space Center.