Official Was Never Told How Cold Booster Got : Might Have Delayed Flight, He Testifies

A space agency official who gave final approval to launch the space shuttle Challenger testified Tuesday that he was not aware that temperatures of less than 10 degrees Fahrenheit were being recorded on the right solid rocket booster in the final hours of countdown.

Had he received the reports, the abnormally low readings would have forced him to “get some answers” before the flight was allowed to proceed, Jesse Moore, the head of the National Aeronautics and Space Administration shuttle program, told a Senate science subcommittee investigating the Jan. 28 disaster.

Moore said it was “a correct assumption” that he and a select group of a half dozen NASA officials controlling the final countdown were not informed about the low temperatures detected by an infrared device.

“Is a temperature reading that low something that would have caused you a high sense of alarm, where you would have said, ‘Look, I need to know more about this before we take any more action’?” Sen. Donald W. Riegle Jr. (D-Mich.) asked.

Moore responded: “I believe that I would have asked more questions about what the readings indicated, what were the differentials between the left booster reading and the right booster reading, and so forth. Those were the kinds of things I would have put back down in the system to get some answers.”

Instead, the countdown was allowed to continue, and 73 seconds into flight the Challenger and its seven-member crew were engulfed by a cataclysmic fireball--the worst disaster in the history of manned space flight.

Contentious Hearing

At an often contentious hearing, the senators repeatedly pressed both NASA officials and former Secretary of State William P. Rogers, the head of the presidential commission investigating the accident, for new facts about the investigation.

“At this particular juncture, it looks like an avoidable accident rather than an unavoidable one,” said Sen. Ernest F. Hollings (D-S.C.).

Although NASA officials have persistently warned that they have not pinpointed the cause of the catastrophic explosion, the right solid rocket booster and the effects of cold weather on the performance of crucial seals between its many sections have emerged as a prime focus of investigators trying to reconstruct the tragedy.

Moore’s testimony came as physicist Richard P. Feynman, a member of the presidential commission charged with determining the accident’s cause, said in Florida that evidence he gathered at the Kennedy Space Center makes it clear that the low readings on the bottom of the right booster were accurate--and that cold weather played a crucial role in the explosion.

The most prominently advanced theory holds that a flaw in rubber O-rings that seal booster rocket sections allowed jet-hot propellant to escape from the right rocket and burn against the shuttle’s huge fuel tank, heating the gases inside to the point of explosion.

The O-rings have been a source of growing concern at NASA for three years and are known to have suffered partial erosion on several other flights. A rupture of the seal would require the failure of both a primary O-ring and a secondary O-ring--something that, before the Challenger flight, space agency engineers maintained could not happen.

NASA officials testified that the readings recorded by an infrared device were so low that they were not certain of their accuracy. The device is difficult to calibrate, they said, and Feynman was sent to Florida to investigate the readings.

Moore said that the temperatures were recorded by a team of technicians dispatched just before launching to determine whether ice forming on the launching pad posed a danger to thermal tiles on the Challenger’s underbelly.

Ice Held No Peril

He told the Senate Commerce subcommittee on science, technology and space that the team reported back only that the ice appeared not to be dangerous and that no further deliberations about the impact of cold weather were held.

NASA officials are investigating why the temperatures were not relayed up the chain of command, Moore testified.

“What specifically happened relative to temperatures,” he said, “and how far they got up the system is something that we are looking at right now.”

A Kennedy Space Center source involved with an internal space agency investigation said that it appears the team members did not report the recordings simply because “they weren’t supposed to do that.”

The source explained: “They were ET (external tank) people, not booster people.”

It was 38 degrees at the time of launching--seven degrees above the minimum allowed under NASA safety standards.

Moore and other officials brought before the subcommittee at a packed hearing were reluctant to discuss their thoughts on what doomed the Challenger or to share much of the information gathered since the disaster.

Fuel Tank Theory

They said also that it is too early to rule out the external fuel tank as a possible cause in the explosion. One theory, for example, conjectures that a leak in the fuel tank blew gases across to the solid rocket booster and triggered the explosive exchange of heat and fuel.

Rogers, head of the presidential commission, which has 120 days to investigate the accident, said it would be “a mistake to focus all of our attention” on the O-rings.

“It’s possible the external tank was involved,” Rogers said. “We know that the strut that connects the booster with the external tank was broken. Whether it was broken at that time (in the first seconds of launching, when a black puff of smoke emerged from the rocket) or later on is not determined. But we expect we may be able to determine that.”

At more than one point, the senators reminded witnesses that NASA would be forced to rely on Congress for more money to replace the $1.2-billion Challenger and resume its shuttle program at full strength.

Sen. Hollings scolded acting NASA Administrator William R. Graham: “Bluntly, there’s an old saying that ‘whose bread I eat, his song I sing . . . .’ ”

Hollings added: “The President has appointed his commission, but the people have appointed us. We’ll be around longer than any 120 days. And, to get right to the point, I not only got your authorization, I’m on the appropriation end, and the budget end. I got you three ways. So I want answers to my questions.”

Dispute Over Secrecy

Earlier, Hollings and other senators had sharp exchanges with Rogers about being allowed access to commission transcripts. Rogers maintained that his commission would reserve the right to meet in private and not share information until it reported to the President after its term expires.

Rogers did promise, however, that “all the facts” gathered by the 13 commissioners--who come from the ranks of science and space exploration--eventually would be made public.

In addition, senators raised questions about the possibility of a decline in NASA standards. At one point, Neil Armstrong, the vice chairman of Reagan’s commission, who was the first man to walk on the moon, was asked by Hollings if he would fly on a shuttle mission “knowing what you know now.”

In response, Armstrong recounted a conversation he had had with current astronaut John Young shortly after the accident. He said Young told him: “We’re with you on this. None of us wants to go again until we really understand what happened and we’ve got it fixed.”

“That’s the same way I feel at this point,” Armstrong concluded.

Staff writer Maura Dolan contributed to this article.