John Sandford - Saturn Run

A meteor strike?

She pulled up a comm window and called Engineering. “Talk to me.”

Wendy Greenberg’s face popped up: another MIT grad, thin, intense, vid specs linked to the major readouts. Before Becca could ask, Greenberg said, “I was about to call. Reactor 2 safed itself.”

What? “How’s Number 1?”

“Just fine. We’re still running at fifty percent power. All the telltales are normal on both reactors.”

“I’m on my way down,” Becca said, her heart beginning to thump. Before she could move, a new comm window opened up on her screen: Captain Fang-Castro. “Becca, thrust just dropped by fifty percent. What’s our status?”

“Reactor 2 has gone into safe mode. I’m on my way down. I’ll call you as soon as I know something.”

As Becca hurried down the corridor to Engineering, her pocket com chimed a priority call. Palming the screen, she saw Crow. Oh great, Mr. Stick Up His Ass Security. “Dr. Johansson, is something going on that I should know about?”

“Reactor 2 put itself into automatic safe mode. Reactor 1 is running fine. There’s no danger, no security risk, and I expect I’ll have Number 2 back online by morning.” Crow looked dubious but only said, “Thank you, Doctor, I look forward to talking to you tomorrow.”

Then that will make one of us, Becca thought. Here they were less than two weeks out and something had gone off.

Becca had to thread through the dual air locks into Engineering. Normally one stayed closed, since Engineering and the forward part of the ship ran separate air systems as a routine safety precaution, but both had engaged when the reactor threw the fault. As she headed to Propulsion Control, she could hear a buzz of concerned conversation. A half-dozen techies were examining a status monitor. Greenberg was there with Martinez, the chief of station operations.

“What have you got?” she asked Greenberg.

Greenberg shook her head. “As far as we can tell, the reactor safed itself for no good reason. The process safety subsystem sent Number 2 into its shutdown routine because it detected a loss of pressure in the primary coolant path. The thing is, the coolant path subsystem logs show the sodium pressure entirely nominal, not even a quiver. Best as we can figure, the process safety subsystem got it wrong. Furthermore, it seems to have righted itself—currently it sees all cooling system parameters, in fact all system parameters, as being exactly where they should be.”

Becca was looking at the status monitor: “So, we’re a hundred and fifty percent sure that there is absolutely nothing wrong with the coolant system? That there’s no physical reason this reactor shouldn’t be online?”

“Joe is about to go pull data directly off of the pressure sensors, to be three hundred percent certain, but everything in all the logs in all the systems says we’re good. The process safety subsystem momentarily hallucinated and hit the panic button for no good reason. As far as we can tell.”

“Maybe for no good reason, but there’s always a reason. Joe, make your readings. Wendy, if they check out, bring Number 2 back online at twenty-five percent for an hour and fifty percent for another hour. If everything looks perfect, take it up to full power.”

“Okay. But I’m worried.”

“So am I—but we’re not going to blow anything up because a bad piece of data takes the reactor down,” Becca said. “If it was the other way around, if a bad piece of data kept it up when it should be taken down… then we would have a problem.”

Becca hung in Engineering until Joe began calling back: all the pressure sensors showed pressures were normal. No problem anywhere.

Walking back to her quarters, Becca thumbed up Fang-Castro. “Short version, the safety computer choked on a bad byte of data. We’re checking out the hardware personally, but every indication is we’ll be back to one hundred percent power by morning.”

The medsystem computer woke Becca at 07:45, having allotted her an extra forty-five minutes to compensate for her delayed bedtime. This was a good sign. The absence of sleep-interrupting emergencies or fretful phone calls from Command meant that nothing untoward had happened during the night. That meant that the reactor was online and everything was nominal again.

Happily, her deductions were right. When she got to Engineering command at 09:00, things couldn’t have been running more smoothly. The one-time glitch had, indeed, proven to be one time. Greenberg had pulled in a double shift for the morning so that a full complement of people could run hardware and software diagnostics without taking anyone off of normal operations. So far they’d found nothing but a textbook operation; everything was so on-spec that she could almost imagine it was a computer simulation.

The ship’s engines were back up to full power, adding a good four kilometers per second every day to the ship’s already impressive velocity. The VASIMRs’ control systems continued tuning the mix of hydrogen and oxygen, ratcheting up the exhaust velocity past a hundred kilometers per second. Just as planned, they were sacrificing some of the thrust and some of the acceleration but saving a lot of reaction mass. Without these clever, clever engines, the ship would’ve been twice as big and, Becca thought, her headaches three times bigger.

She’d have to find some way to reward Greenberg and her team for doing such a good job of dealing with and dismissing what had proven to be nothing more than a minor irritation.

At 10:23:47, the Reactor 2 safety subsystem reported a drop in primary sodium coolant pressure and initiated a safe shutdown of the reactor.

It was the first shutdown, all over again, except the inquiries didn’t go as well.

“No, Captain, I can’t tell you when I’ll have Reactor 2 back online. I’ve got a double complement of people here and we’re all over it, and, once again, it looks like a hiccup in the data. Which shouldn’t have happened once, and definitely not twice. Until I track it down, we’re at half power.”

As they worked through the computer data, the last thing she needed right now was another call from Crow, but there it was. At least he was gracious enough not to look smug. In truth, he looked as noncommittal as ever; Becca wondered, a bit maliciously, what it would take to throw him off his guard.

“Dr. Johansson, we should have a conversation.”

“I will be happy to do that, Mr. Crow, as soon as I’ve figured out what’s causing the glitch in Reactor 2’s safeties.”

“You misunderstand me,” Crow said. “We need to have a conversation, now.”

“Really, I’ve got more pressing matters than indulging Security’s paranoia.”

“You don’t have any choice, I’m afraid. We either talk now, or I have a marine come down and fetch you, and we’ll talk in the captain’s office. Pick one.”

Becca nodded: “Okay, fine. What would you like to know?”

Crow looked down at his tablet. “I’ve made up a list of questions. Some are very simple, but bear with me. I want to make sure I’m not making any wrong assumptions. You’ve had two incidents with Reactor 2 in less than twelve hours, but Reactor 1 is one hundred percent operational?”

“Correct. Unit 1 is behaving perfectly. And, to clarify, there’s no problem with the Reactor 2 or any of its related hardware, as far as we can tell. It’s the safety subsystem that keeps registering a coolant problem and shutting the core down. Which is exactly what it is supposed to do, except there’s no reason for it to be doing that.”

“What’s different about Units 1 and 2 and why hasn’t Unit 1 also gone off-line?”

Becca had to grudgingly acknowledge Crow’s talent for getting to the heart of the matter. “There’s the rub—there is absolutely no difference between the two units. The reactors, heat exchangers, turbines, and generators and the computer systems are absolutely identical. Well, the hardware is as identical as we know how to make it, and the software is one hundred percent identical. So, we’d expect a purely software glitch to appear in both units.”