“Okay. It’s kind of self-correcting.”
“That’s right; the whole thing is stable. That’s how they design civilian reactors. But in the case of NERVA, that coefficient was positive, at least for some of the temperature range. So when the temperature went up, the reactivity went up, too—”
“And the rate of fission increased, leading to a further temperature rise.”
“And so on. Yes.”
Michaels glared at Udet. “I can see the fucking headlines now, Hans. Why the hell did we fly an unstable reactor?”
Udet sat forward, his face pale, a muscle in his neck rope-taut with anger. “You must understand that we are not building a reactor to supply domestic electricity, here. We are not heating coffeepots. NERVA 2 is a high-performance booster, a semiexperimental flight model. Stability is not always the condition we require.”
Michaels frowned. And you just hate having to answer these asshole questions, don’t you, Hans? “Why do we need instability? What do you mean?”
Seger put in, “It’s like a high-performance aircraft, Fred. A ship that’s too stable will wallow like a sow. So you might design for instability. If a bird’s unstable, it can flip quickly from one mode to another; if you can control that, you’ve gained a lot of maneuverability”
“But that’s a big if, Bert. And evidently, when it got to the wire, we couldn’t control it. Hans, why didn’t you beef up the control system to cover for this?”
Udet punctuated his words by thumping the edge of his hand on Michaels’s desk. “Because — of — unacceptable — weight — penalties.”
Michaels dreaded having to put this man in front of the commission. “Let’s move on. What next?”
Udet said, “Events unfolded rapidly. The power output began to rise exponentially, doubling in a fraction of a second. The fuel pellets — which are uranium carbide coated with pyrolytic carbon — shattered from the thermal shock of the sudden power rise. The flow passages within the core melted. The moderator systems became inoperative. There was a hydrogen explosion, which ruptured the pressure shell and the biological shield—”
“All right.” Michaels found himself shuddering. “We know the rest.” Jesus. What a mess. “So the whole damn thing was caused by faulty hydrogen pipelines.”
Bert Seger nodded, and then he startled Michaels by saying: “It’s actually not as bad a scenario as you might have feared.”
“Not as bad? What the hell are you talking about, Bert?”
“The glitches in the hydrogen flow came from a simple component failure. What you had was ruptures in a six-foot length of stainless-steel fuel line, five-eighths of an inch in diameter, carrying liquid hydrogen from the tank into the nuclear engine. That’s all. So it’s easy to fix.”
“Why did the damn pipe rupture?”
“Well, we were flying with a new innovation,” Seger said, “that was supposed to guard against the effects of vibration. Each length of the pipeline had two vibration-absorbing ‘bellows’ sections in it, with wire-braid shielding on the outside. When the new line was put through vibration tests on the ground, it worked perfectly.”
“So how come—”
Udet said, “It turned out that in the atmosphere, the liquid hydrogen running through the pipe caused ice to gather on the braided shield. And that altered the characteristics of the pipe, enough to enable it to dampen out the most severe vibrations in the bellows during our testing.”
“Oh,” Michaels said. “But in the vacuum, no ice could form.”
“And those little bellows sang like a rattlesnake,” Joe Muldoon said. “When the Saturn first stage started its pogoing, the bellows couldn’t handle it. They just fell apart.”
Michaels asked Udet, “But how come you didn’t pick up the ice thing when you ran vacuum ground tests on the bellows?”
Udet faced Michaels squarely; he looked calm, somehow confident. “We did not run vacuum tests on this component. We did not anticipate the necessity.”
Michaels held his gaze for long seconds, but nothing more was forthcoming: no more data, no justification, no apology. “Well, I will be dipped in shit. Joe?”
Muldoon leaned over the desk and tapped the report. “This is where we show ourselves as culpable, Fred. Those goddamn bellows were Criticality One components: that is, their failure was liable to cause the loss of the spacecraft. But we didn’t test them out under true flight conditions. And, what’s worse, we’ve now dug out evidence of bellows problems on the S-NB’s previous unmanned test flight, although in that case we didn’t lose the mission.”
I’m dead meat, Michaels thought.
They could have anticipated the fault, and that was always deadly. And, it was always the way, some obscure little asshole technician somewhere at Marshall or the Cape would have written a report predicting precisely the failure they’d suffered, a report which no doubt had been laughed off and suppressed by NASA senior management, a report which was no doubt falling into the hands of some congressman even then…
“Culpable. Jesus. How I hate that word.”
Michaels got to his feet. He crossed to his window and folded his hands behind his back as he stared out over Washington. The light was fading from the sky, softened and stained by smog.
“I don’t want to minimize the impact of this, gentlemen. Quite apart from losing the crew, this is a genuine catastrophe. I have the ecology lobby around the world jumping up and down on my back. We’ve even been criticized for bringing a radioactive Command Module back into the atmosphere. There was strong opposition to flying nuclear materials into space even before the flight. And now the Russians have a fucking Soyuz up there taking pictures of the out-of-control glowing radioactive core we’ve abandoned in orbit.
“You’re right, Joe; there’s no doubt in my mind — and there won’t be in the minds of public, Congress, and White House — that we’re culpable. And now we have to put our house in order, and be seen to be doing it.
“All right, gentlemen. Your recommendations as to what we do next?”
Seger was the first to speak. “The main recommendation is not to panic here, Fred. I hear what you say; this accident we’ve suffered is unacceptable. There’s no doubt about that. But the problems are straightforward and limited in scope. We have to get S-NB flying again, as soon as possible, with men aboard, and push on for Mars. We can’t lose our nerve. That’s the message you have to take back to the Hill, Fred.”
More bland generalities, Michaels thought, delivered in Seger’s weird, intense, gung-ho style.
“Hans?”
Udet sighed. “Bert is right. We must repair our NERVA program and move on. We have no other option, if we are to reach Mars. It is as simple, and as dramatic, as that.”
“Well, hell, I disagree,” Muldoon said harshly. “With both of you. I think that if they let us keep on flying at all after this fuck-up, we’re going to have to do a sweeping review of the whole system, spacecraft, booster stages, management procedures. Everything.”
“And if you do that,” Seger said hotly, “you risk throwing away everything. You’ll come out of that process with an immature system, overdesigned and carrying too many changes, which will hit us with a host of problems we’ve not even thought of yet.” He turned his glassy stare on Michaels again. “Look, Fred, this is a lousy business, and I wish it hadn’t happened, and I’ll spend the rest of my life trying to come to terms with this: what I did wrong, what I could have done differently to avoid this, and all the rest of it. And I’ll do all in my power to avert such an accident in future. But at the end of the day, we’re flying experimental craft here. Pilots die flying experimental craft; they always have. You lose crew. And that’s a truth we’ve got to learn to live with.”