Investigators Hint at Short Circuit in Delta Explosion

The sudden engine shutdown that doomed an unmanned Delta rocket Saturday may have been caused by a short circuit, investigators said today.

The Delta failure follows the explosion of an Air Force Titan 34-D rocket April 18 and the destruction of the shuttle Challenger on Jan. 28, shocking the nation’s space program with its worst string of failures in years.

With all three programs grounded, only the National Aeronautics and Space Administration’s Atlas-Centaur rockets are still on flight status, but Lawrence Ross, chairman of the Delta accident investigation, said “there’s a high probability” the next flight of an Atlas-Centaur, now set for May 22, will be delayed.

He said the engines used by the Delta’s first stage and that of the Atlas-Centaur are both built by Rocketdyne and have some similarities.

“So there’s some commmonality between the two and I think it would be prudent for us to be very thorough in understanding what happened to the Delta inasmuch as what happened to the Delta may have implications (for the Atlas-Centaur),” he said.

John Yardley, president of McDonnell Douglas Astronautics Co., builder of the Delta, said “it sure seems funny” that three different types of spacecraft could be lost in such a short period.

“The odds against these are, based on their records, something like greater than 1 in 10,000,” he said. “There may be some common thread that we haven’t found.”

NASA morale battered, Page 14.