NASA decided on a 24 hour turnaround, but there was a new problem at the Weather Station, with exceptionally cold temperatures forecast for Florida.
‘We prepared forecast for the next day,’ said John Weems of the NASA Weather Station. ‘We knew the winds would be decreasing, but the real concern was the very cold temperatures that were due in the area. We put together a 12 hour forecast and presented it to the Mission Management people, presenting temperatures of 24F (minus 5 Celsius) at the pad for the next morning.’
NASA remembered that Morton-Thiokol had been concerned about low temperature launches and made a call to their Utah headquarters.
‘A manager came by my room and asked me if I was concerned about an 18 degree launch,’ recalled Ebeling. ‘I said ‘What?’ – because we’re only qualified to 40 degrees. I said ‘what business does anyone even have thinking about 18 degrees, we’re in no man’s land, we’re in a big grey area.’
Ebeling called his O-ring task force team to assemble in his office, given the O-rings had never been tested below freezing, but now the estimated temperatures the exposed SRBs would experience were some 18 degrees colder.
‘We discussed what might happen below our 40 degree qualification temperature and practically to a man we decided it would be catastrophic,’ added Ebeling.
A call was immediately made to the NASA Marshall Space Flight Center (MSFC) in Alabama to raise concerns.
Thiokol recommended that we could not launch until the weather warmed up in the afternoon,’ said NASA senior manager Jud Lovingood. ‘Well I told them they couldn’t make that recommendation. They had to give us a temperature that we could launch with.’
A formal presentation would have to be made, two hours after speaking with Lovingood and just 15 hours before launch, via a teleconference at which Thiokol would need to given their reasoning for a no launch decision – a power contractors held, but were scared to make given the effects on the Shuttle schedule.
Thiokol engineer Roger Boisjoly – one of two specialists (the other being Arnie Thompson) on the SRB joint seals – grabbed anything he could from his office to show how the temperature would lead to a failure of the SRB’s O-ring and the destruction of the Shuttle.
‘Unfortunately in our rush we didn’t have time for a dry run at what we’d present to NASA,’ noted Boisjoly. ‘I had no idea what my colleagues would present and I had no idea what I’d bring to the meeting.’
Thiokol engineers still managed to give what they believed to be compelling evidence that the low temperature would slow down the sealing of the O-ring primary and secondary seal, leading to hot gas leaking out of the joints and an explosion on the launch pad as soon as the SRBs ignited.
‘The entire Thiokol group recommended no launch,’ remembered Ebeling, as they recommended a minimum launch temperature of 53F (11C). The expected rubber stamping of that recommendation was expected from NASA on the other end of the teleconference. However, they would be proven wrong.
‘I thought it was a very poor briefing,’ said Lovingood. ‘To make such a huge statement on flight safety, it was an extremely poor briefing.’ NASA engineers at MSFC started to pull apart Thiokol’s data.
‘You don’t do data by emotion,’ added Lovingood. ‘You can’t go up there and say ‘hey, I’ve got a gut feeling this thing is going to blow up.’ They’d take you to the funny farm.’
‘We’re always probed on rational, but that night I was hammered (by NASA engineers) way more than I had experienced as an engineer in the aerospace industry,’ said Boisjoly.
‘We always do that with our contractors, ‘ countered Lovingood. ‘What we did that night was mild, compared to what we normally do.’
The problem escalated during the meeting. NASA could not go against a contractor’s ‘no launch’ recommendation. However, such a recommendation of a minimum launch temperature would destroy the ambitious launch schedule of the Shuttle.
‘I turned to my fellow managers and said if these guys persist in this decision not to launch, then we can’t launch, and they agreed with me, we were at their mercy,’ added Lovingood.
‘As soon as the button was pressed to mute NASA from our meeting, the managers said ‘we have to make a management decision,’ said Boisjoly. ‘It was obvious they were going to change their decision to launch decision to accommodate their major customer.
‘But surely the photographs I had showed that the more black that you see between the seals, the lower the temperature, the closer you are to a disaster. I was told I was literally screaming at the managers to look at the photos, but they wouldn’t look at them.
The general manager of Thiokol turned to his three senior managers and asked what they wanted to do. Two agreed to go to a launch decision, one refused.
‘So he (the general manager) turns to him and said ‘take off your engineering hat and put on your management hat’ – and that’s exactly what happened,’ said Boisjoly. ‘He changed his hat and changed his vote, just 30 minutes after he was the one to give the recommendation not to launch. I didn’t agree with one single statement made on the recommendations given by the managers.’
The teleconference resumed and NASA heard that Thiokol had changed their mind and gave a recommendation to launch. NASA did not ask why.
‘That was stupid on our part, that was dumb,’ said Lovingood. ‘We should have said ‘give us your rational for changing your mind’ but a guy sits in a meeting, that is a good for launch meeting and he doesn’t stand up in front of the train to stop it, he’s go. No one stood up, so everyone was go for launch.
‘But I remember going home and telling my wife that I sure hoped we made the right decision, as I had misgivings about it.’
‘I went home, opened the door and didn’t say a word to my wife, ‘ added Boisjoly. ‘She asked me what was wrong and I told her ‘oh nothing hunny, it was a great day, we just had a meeting to go launch tomorrow and kill the astronauts, but outside of that it was a great day.”
[...]
