Time to start getting ready to go home, eh?
"Even with the reactor scrammed, the radiation in there's gotta fry the dust, A.J.," Brett said doubtfully, looking on as Jackie prepared to pour approximately three liters of Faerie Dust into an instrumented funnel-shape that was positioned above Nebula Storm's main reactor, fitting precisely into the small but fatal hole in the casing.
"Oh, no doubt about that," A.J. agreed cheerfully, and Horst continued for him, "And if we had not access to the many tons of drive dust made for Odin, maybe we would not be risking our most versatile sensing method this way, at least not yet. But the drive dust was meant for long-term space exposure and was hardened by some complex metamaterial design to resist a great deal of radiation. Mostly beta radiation, admittedly, and I would caution against betting that it will survive long inside a nuclear reactor, but it should last long enough to give us the data we need."
The problem was, of course, that opening up a fueled nuclear reactor whose core had been punched was not something one did casually; in fact, with the tools available to the combined expedition it was something that only the insane or the desperate would attempt. Still, even something crazy was better attempted with the maximal amount of knowledge.
A.J. felt he'd redeemed himself slightly after his prior blindness to the simple solution of his Faerie Dust's mobility, by realizing that the tougher, simpler drive dust would provide a sacrificial method to obtain a clear idea of what the precise condition of the core was. A few devices back on Earth might have been able to look straight through the reactor casing, but – after all – the casing was specifically designed to prevent radiation of any kind from getting through it. While that was meant mostly to prevent radiation from leaking out, it was equally efficient at preventing any radiation from getting in.
He was actually pretty proud of how he'd solved the problem of knowing what they hit. Jackie and Brett had managed to put together a detailed model of the original reactor and core, and simulated what the drive dust motes would "see" as they encountered the various components. While there wasn't really enough data for the drive dust to identify, say, uranium versus steel in isolation – unlike his bleeding-edge Faerie Dust, it wasn't built with multimodal sensor components -- but the way in which high-speed impacts would break the pieces apart would still yield a fairly good rule-of-thumb heuristic to recognize the different types of things expected inside the reactor.
So A.J. would run his custom sensor analysis software on the drive dust as it worked its way, probably quickly degrading, through the reactor casing, and then when he'd processed the data as best he could, he'd send to to Brett's model, where the interior would be mapped out and – with luck – the precise nature, position, and extent of the damage caused by Fitzgerald's last shot would finally be known, allowing them to proceed with precision; possibly they'd even be able to figure out a way to do the repair without actually having to open the casing, working through the already-extant hole as though doing a laparoscopy.
"Ready, A.J.?" Jackie asked.
A.J. checked all the displays in his VRD. "Telemetry's good for the whole mass. Since we're in vacuum we don't need to worry about any of the messy reactions that can happen in a reactor that's been breached. Yep, we're go."
The New Zealander gave her a thumbs-up. "Model's ready to take input as fast as A.J. can feed it to me."
"All right. Starting the pour… now."
In Europa's roughly 1/8th gravity, the speed of the almost liquid mass of drive dust motes looked more like the lazy flow of stage fog off the edge of a stage, dreamlike, unreal. But there was nothing unreal about the torrent of data that abruptly filled the bandwidth A.J. had allocated. "Data stream coming in loud and clear." Another running tally started to rise. "Yeah, it's lousy with rads in there. Attrition rate is already noticeable. Progress isn't terribly fast, though. The motes are using gravity assist where they can, but that core's packed pretty tight. Lessee…" He made some basic assumptions, plotted things again. "Yeah, it's definitely going to be eating into the supply fast. Horst, I think we'll need twice that much to finish the scan, get it set up, would you?"
Jackie joined them in Nebula Storm's control room, pushing back the helmet with a relieved sigh; A.J. knew that she was always – understandably! – tense when working near the damaged reactor. "When does Brett start getting anything?"
"Getting stuff now," Brett said. "Only starting the outline at the entry point, but enough to show it's working. Don't get too eager; it's going to be a couple hours, probably, before we get enough data to give you a look."
Jackie smiled. "It will take us days to take her apart, so a few hours to know whether we have to, or what way we have to? Priceless."
"A.J.," came Larry's voice, "You got a minute?"
"Now I do," he answered, leaning back a little in the seat. "What do you need?"
"We got another quake, about 3.4 on the adjusted Richter, and the dust we spread around the whole area did a lot of recording. Can you –"
"No problem. I actually have a suite of programs designed for deriving data out of that kind of return." He grinned suddenly. "Helen knows; you could almost say it was the earlier version of that suite that GOT us into this mess in the first place."
"You mean the analytical program you used that gave us a picture of the Bemmie fossil before we even dug it up?" He could hear the smile in her voice even if he hadn't seen it in the HUD imagery his VRD showed. "That's right, you set off little charges or something and mapped the acoustic, along with other signal returns."
"And the combination almost got me thrown off your expedition as a practical joker," A.J. finished, with a chuckle. It was one of his fondest memories; a revelation so dramatic that even the people who'd called him in very nearly didn't believe him – probably wouldn't have, if Joe hadn't known him so well. Plus, that was when he'd first met Helen. Not that he'd even imagined at the time…
A second firehose of data started dumping into his systems; this one, however, was for much more familiar analysis, and with even the relatively limited systems available on the Nebula Storm and Munin was much easier to interpret. In about 15 minutes he was able to call Larry back. "Well, some interesting results for you to look at. Some of it I have no idea how to interpret, but I can tell you that it looks like there's a general discontinuity about a kilometer down; I'd say we've got evidence for the Thin Ice model."
"A kilometer?" Larry's voice was incredulous. "That's … almost ludicrous. Unless… lemme take a look." Several minutes passed, interspersed with Larry and Anthony debating some of what they saw in technical language. Finally Larry said, "Hey, listen up, everyone." The tone and his use of 'everyone' keyed the general broadcast. "Returns from that last quake gave us the data we needed. This whole area's part of something called the Connamara Chaos, and turns out it's an apt name below the surface as well as above. Everything's jumbled, no clear structure – and there's some really strange returns; I suspect that there's some subtle interaction of different phases of ice that's making it very hard to interpret some of what we're seeing.
"But I think we've got good evidence for an impact several thousand years ago; that's what messed up this part of Europa, and it actually thinned the surface over an extended area; I think we can see the thickness trending up in all directions away from us. It's probably more like ten kilometers thick normally, but right around us the crust isn't much more than a kilometer thick."
"Does that mean that Athena may actually punch through?" Jackie asked.
"If we stay here long enough, and keep drilling in the one spot, I'd say certainly. So we've got a good chance of actually getting the first sample of a planetary internal ocean. Real science, guys!"
"That's about three, three and a half months of running Athena," Dan said after a moment. "But then she was meant to run for a long time. If everything else holds out, I don't see any reason we can't do that. And we're not going to be done with everything else before then."
"Does this have any implications for our safety?" Madeline asked. "I don't want to lessen the enjoyment of this discovery, but –"
"Completely understood, Maddie. We're still getting data on the … tectonic dynamics of this situation, so we can't really say for sure. On the other hand, there've been several unmanned probes of the Jovian system in the last thirty years which observed Europa pretty closely, not counting the Europa probe that glitched, and none of them have seen clear evidence of surface breaches even here, so I'd say we should be reasonably safe. Keep everything secured, is all I'd recommend."
That's a relief, A.J. thought to himself. If Maddie decided their current location was too dangerous, they'd have to figure out how to MOVE the crashed Nebula Storm far enough to make it safe, and then land it safely again. NOT something I want to even think about trying.
He checked both sets of processes; the reactor analysis was still running, and the spread-sensor net was still running. Hm. Another momentary spike of that lethal chemical dihydrogen monoxide.
He'd seen several of these momentary, almost-in-the-noise readings of water vapor, but the net still couldn't localize them. Which meant he didn't have much to hand to the others.
It did occur to him that it might just be from the force of a quake, maybe momentary cracks vaporizing some of the ice somehow.
But the others were all busy talking about the ice thickness, so he decided not to bother. Yet. The scientists continued talking about the implications of this latest find while he leaned back and took a nap.
It was a curse that awakened him; the usually polite and cheerful tones of Jackie Secord saying "Oh, shit."
That kind of thing immediately brought A.J. to full consciousness. "What's wrong?"
He could see by the expression on Jackie's face that it was even worse than he'd thought from the cursing. She pressed a control and the modified model of the interior of the reactor appeared.
It looks almost as jumbled as the damn ice! "What the hell…?"
"Ricochets." The word itself was spat out like another obscenity. "That damned bullet penetrated the Nebula Storm's hull, then the reactor vessel, then because the reactor was mounted directly on the lower hull it bounced off the hull the second time, and bounced a couple more times inside the reactor before it stopped."
"I guess that means it's going to take longer to fix." Larry said finally.
A.J. winced, and Jackie's face was grim as she answered. "No," she said, and took a deep breath.
"It means there's no way to fix it," she said slowly. "It's not a matter of one clean hole through; the whole core has been… almost scrambled, like an egg.
"Madeline… I'm sorry, but Nebula Storm will never fly again."