ROBERT SIEGEL, HOST:
Thirty years ago today, seven astronauts died when the space shuttle Challenger exploded. The nation watched in shock. The shuttle program stalled as investigations began. But rocket engineers with NASA contractor Morton Thiokol knew exactly what had happened. The night before the launch, they had tried to stop it. Soon afterwards, two of them anonymously described the fatal decision to NPR. One of those engineers has died. The other just decided to let NPR name him. He spoke with NPR's Howard Berkes back in 1986 and again today.
HOWARD BERKES, BYLINE: Bob Ebeling is 89 now and was desponded on February night 30 years ago when we sat at his kitchen table in Brigham City, Utah. Ebeling and four colleagues had tried to stop the Challenger launch. They presented data to Morton Thiokol engineers and NASA officials and argued that it would be too cold to launch. The rubber seals on the shuttle's booster rockets wouldn't seal. The engineers were overruled, and that night, tearful and angry, he told his wife, Darlene...
BOB EBELING: It's going to blow up. And I did my best to let the world know I was one of the few that really was close to the situation.
BERKES: The situation went on for hours as Ebeling and other Thiokol engineers presented data repeatedly. It was unequivocally clear to them.
EBELING: But NASA ruled the launch. They had their mind set on going up and proving to the world they were right and they knew what they were doing. But they didn't.
BERKES: A presidential commission found flaws in the space agency's decision-making process, but it's never been clear why NASA was so determined to launch. The space agency desperately tried to launch the shuttle routinely and reliably. President Reagan was set to give the State of Union address that night and reportedly planned to promote the Challenger flight. Whatever the reason, Ebeling says it didn't justify the clear risk.
EBELING: Had they listened to me and wait for the weather to change, it might have been a completely different outcome. There was more than enough people there to say, let's give it another day or two, but no one did.
BERKES: Ebeling retired soon after Challenger. He suffered deep depression and has never been able to lift the burden of guilt. He still feels, as he told me in 1986, he should have and could have done more. Sitting in a big easy chair in his living room, his eyes watery and his face grave, Ebeling concludes he was inadequate. He just didn't argue the data well enough, he says. He's prayed about this for the last 30 years.
EBELING: And I think that was one of the mistakes that God made. He shouldn't have picked me for that job. I don't know. But next time I talk to him, I'm going to ask him, why me? You picked a loser.
BERKES: I remind Ebeling what his late colleague and friend Roger Boisjoly once said. Boisjoly was the other Thiokol engineer who spoke with NPR anonymously 30 years ago. They were talking to the right people, Boisjoly once told me. They were talking to the people who had the power to stop that launch, and they did all they could. Maybe, Ebeling says to me with a weak wave as I leave, maybe Roger's right. Howard Berkes, NPR News.