Voyage (48 page)

The next day she had the locks changed, and packed up Mike’s stuff and sent it to Huntsville. And she put the Portofino apartment up for sale.

When the first draft report of NASA’s internal report landed on his desk, Michaels called a meeting of Seger, Muldoon and Udet, in his office in Washington.

The three of them sat in a row on the other side of his desk. Muldoon was tense, angry, uncomfortable; Seger seemed eager, energetic, somehow too bright; and Udet was reserved, watching Michaels and the others through his pale blue eyes.

Michaels picked up the draft report and dropped it on his desk. ‘I’ve tried to read this. I know I’m going to have to answer for it line by line. Gentlemen, I want you to walk me through this fucking blow-out. Step by step, over and again, until I understand. You got that? Hans, you want to lead?’

Udet nodded crisply. ‘Of course, Fred. The malfunction occurred at the time at which we were preparing the S-NB for its restart burn. I will remind you that the rocket had functioned flawlessly during its first burn –’

‘I remember.’

‘The moderators were adjusted to lift the temperature of the core to its working range of three thousand degrees. The turbo-pumps were started, and hydrogen began to flow through the cooling jackets and the core. We registered thrust rising to its nominal levels; the cabin transcript indicates the crew were aware of this. Then –’

‘And then,’ Joe Muldoon said dryly, ‘we hit a glitch.’

The flow of liquid hydrogen into the coolant jackets became intermittent, Udet said. It turned out later that a flaw was developing in the piping carrying the hydrogen to the engine.

Michaels asked, ‘Shouldn’t you have shut down the core, as soon as that happened?’

‘Yeah, that’s standard procedure,’ Muldoon put in. ‘Without coolant, the core is going to overheat.’

‘We had a split-second to make the decision,’ Udet said. ‘That is all. If we had allowed emergency shutdown immediately, we might have lost the engine altogether, and the mission would have been
scrubbed. And perhaps for nothing, if the flow problems had rectified themselves. We were trying to keep options open. The report describes all this.’

‘All right, Hans. Go on.’

‘We adjusted the moderators to reduce the temperature in the core, short of shutting it down. But we could not reach the target temperature –’

Muldoon said, ‘And there you got your first basic design flaw, Fred.’

Both Udet and Seger leaned forward to protest at this, but Michaels waved them silent.

‘We only had one control system – the reactor moderator – and so only one shutdown option. When that failed, we had no way to stop the runaway temperature climb.’

Michaels nodded. ‘Hans?’

Udet spread his hands. ‘We must balance reliability against weight, Fred. This has been the dilemma of all spaceflight: to carry an additional redundant system, or to add value elsewhere? In our opinion, in this case, the moderator system was sufficiently reliable to justify flying without the weight penalty of a backup.’

‘Bert? You want to comment?’

Seger, his eyes brilliant, shrugged his narrow shoulders. ‘We made the best call we could; we did all the tests. We got it wrong. Next time we fly a NERVA, we’ll fix it.’

These things happen
. Not an answer to satisfy the White House Commission, Michaels thought sourly.

‘Go on, Hans.’

‘By now,’ Udet said, ‘the crew were aware that the thrust had died, after that first shove. We were only a few seconds after the first glitch in the flow. Now the hydrogen flow increased, markedly,’ Udet said. ‘It was like a spurt, from the faulty piping. The hydrogen passed its nominal flow rate and effectively flooded the core. We withdrew the moderator further –’

‘And this is another point at which the standard procedure said shutdown,’ Muldoon said harshly. ‘The moderators’ control margin was too low now; we didn’t have full control of the core. But again, we overrode the automatics.’

‘We tried to save the mission,’ Udet said.

‘All right. Let’s stick to the facts for now; we can justify ourselves later. What next?’

‘Now the flow of coolant into the core stopped altogether,’ Udet said. ‘Perhaps at this point the piping failed completely.’

‘This is the key moment, Fred,’ Muldoon said. ‘You have a reactor that’s already unstable. The hydrogen flood has made the core isothermal – that is, at the same temperature throughout – so any changes happen all over the core, simultaneously. And the coolant flow has stopped; the core’s main heat sink, the flow of hydrogen through the jackets, has gone.’

‘So it starts to heat up.’

‘So it starts to heat up. Uniformly. And a lot faster than before.’

Udet said, ‘We tried to shut down. But the moderator was too far out of the core to have any immediate effect. The hydrogen in the core and the jacket boiled quickly, and started to expand …’

‘And now you got a runaway,’ Muldoon said. ‘Because the reactor was designed with a positive temperature coefficient.’

Michaels sighed and locked his hands behind his head. ‘Just pretend I don’t know what you’re talking about.’

Muldoon grinned tightly. ‘I know. It took me a while to figure this stuff out. Look: suppose the temperature of your core rises. And suppose that the core is designed so that when it heats up, the reactivity drops – that is, the reaction rate automatically falls. That’s what’s meant by a “negative temperature coefficient.” In that case you have a negative feedback loop, and your reaction falls off, and the temperature is damped down.’

‘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 boiling kettles. NERVA 2 is a high-performance booster, a semi-experimental 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 due to 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 pipe line 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 now …

‘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 got 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’ve got 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.’

Michaels grunted.
The trouble is, I don’t think we’re going to be allowed to live with it
.

When Udet, Seger and Muldoon had gone, he stood by his window for a long time.

He couldn’t imagine that the manned program would be shut down altogether. That would have such a devastating impact on the American aerospace industry that it was surely politically unthinkable.

But it seemed highly likely to him, almost certain in fact, that the NERVA was going to be grounded.

And without NERVA, how the hell were they going to get to Mars, in this decade or any other? Were they going to be reduced to pottering around in low Earth orbit?

… Maybe he had more immediate problems.

Seger had sounded like he was fraying at the edges. That disturbed Michaels. Both Houses of Congress were going to convene their own hearings on the accident, just as soon as the Presidential Commission reported. Michaels had already had a few clues as to the tone of those hearings; they would be intent on charging NASA’s engineers – meaning Seger, primarily – with criminal negligence.