Wreckage Confirms Shuttle Joint Failure, Top Investigator Says

Two pieces of wreckage from Challenger’s right-side booster show the charred outline of a hole 2 1/2 feet wide, proving that a rocket joint failure doomed the shuttle and its crew, a top investigator said Wednesday.

Col. Edward O’Connor, who is in charge of the shuttle salvage operation, said a piece of burned rocket wreckage brought to shore this week was the final piece needed to pin down the location of the fatal rupture in Challenger’s right-side booster.

“I guess the most important factor about this additional piece of the SRB (solid-fuel rocket booster) is that it proves the symmetry of the burn around the joint that failed and that symmetry clearly points that it was indeed a joint failure centered at the area that we had initially postulated,” he said.

‘Ties Them Into Concrete’

“It not only buttresses the original conclusions, it kind of ties them into concrete and says that was absolutely a joint failure that occurred,” O’Connor said.

He said the data would be useful to the Challenger disaster commission, which must submit its report to President Reagan by June 6.

The rupture occurred Jan. 28 in a joint where the lower two of the right-hand booster’s four fuel segments were bolted together. Wreckage from the upper part of the “burn-through” was found April 13 and the piece referred to by O’Connor was the matching area from the lower fuel segment.

He said the area of the joint where the fatal leak first occurred was eaten away by 5,900-degree flames from the rupture.

‘No Further Evidence’

“We have a hole that was approximately 2 1/2 feet wide there and it was right in the center of that hole that the failure occurred,” he said. “I would expect to see no further analytic evidence . . . that would indicate what that exact effect was that occurred in the middle of that burned segment.”

In another development, it was reported that failure of an O-ring safety seal on the shuttle was almost certain, due both to faulty design and to near-freezing weather the morning of the launch.

New and unpublished test results, conducted for the presidential panel and summarized for the New York Times, also found that the booster rocket joint began to fail at temperatures as high as 50 degrees Fahrenheit, the newspaper reported.

Investigators estimate the temperature of the joint that contained the failed O-ring seal was about 28 degrees. The tests, completed by a working group for the commission, indicated that failure of the O-ring seal was more likely than not at that temperature.

Seven crew members died in the accident.

Nomination Endorsed

Meanwhile, a Senate committee in Washington overwhelmingly endorsed the nomination Wednesday of James C. Fletcher to return as head of the nation’s space agency.

By a 15-1 vote, the Commerce, Science and Transportation Committee sent the nomination to the Senate, where an early vote is expected to confirm Fletcher as administrator of the National Aeronautics and Space Administration, a post he held in the early 1970s.

Only Sen. Albert Gore Jr. (D-Tenn.) voted against the nomination.

Most other committee members indicated Fletcher is the ideal candidate to head NASA as the agency tries to recover from the Challenger explosion.

“I think the fella is just what the doctor ordered,” said Sen. Ernest F. Hollings (D-S.C.).