Well, they'd made an interesting discovery and were hard at work...
"You know," Jackie said, triggering a Cancel and clear on her workspace, "we've been wasting just a ludicrous amount of time on this hookup."
Horst scratched his head. "But we need to have the access to Nebula Storm, and it has to spin –"
"Yes," Jackie interrupted, "but we're going about it all wrong, probably because we were trying originally to figure out how to make it work with Nebula Storm and Munin, and then trying to make the connect to the regular airlock on Nebula Storm."
"So what's your solution?" Mia asked reasonably.
"Go back to what the Odin was originally designed for. If we stick the Nebula Storm in the center of the body along the main axis…" she paused.
She only had to wait a second before Horst struck his own forehead with a muttered German imprecation. "Of course. Rotate all of Odin at the same speed, and we don't need any special connectors; we just integrate the Nebula Storm's forward end into the ship and we can enter and leave as though Nebula Storm were just one more section of Odin."
"And we can leave everything extended, as long as we can clear off any ragged pieces trailing around the area."
Mia was smiling now. "Oh, this will be so much easier, Jackie! I can't believe we didn't see this before. Yes, and there should be very little to clear away; remember that the forward portion of Odin was jettisoned on purpose, and the separation charges designed very carefully."
Horst checked the uplink. "Ah, signal is back to full; we have emerged from behind Jupiter. Brett, this is Horst, are you receiving me there?"
The round-trip delay now, at their maximum communication distance from Europa, was close to eight seconds, so Horst had to enforce patience while he waited; as they'd done this many times now, he was getting good at having conversations with significant time delay built in. It was only about fifteen seconds before he heard the reply. "Horst! Good to hear from you all. Yes, receiving you fine now."
"Glad to hear from you too. We trust that everyone is doing well there?"
"Good enough. Athena's almost done filling Nebula Storm's tanks, and I guess we'll have to start dumping the water until you guys get back for a refuel. Helen's been happily digging away in the ice by remote control, and we've laid out a centrifuge area and started putting together the components we can for that. How're you doing?"
"We've got Munin loaded with the pieces you guys specified for the centrifuge."
"What about power?" A.J. interjected. "Did you –"
"Solved," Jackie said. "There's a spare reactor for the low-G rover we have on board Munin, so we're sending that down to drive the centrifuge. That way you can keep the rover intact."
"Excellent," A.J. said.
"How about you, Petra?" asked Jackie.
"I," the British doctor answered, "have managed to get every duplicate piece of medical equipment into Munin as well." While the others had done the larger engineering work, Petra Masters had been carefully attending to the medical aspects of the trip. "Low-G compensation drugs have been loaded – I am currently working out the best schedule for testing each of us to verify whether any of us have unsupportable reactions to the medication, as we have no true emergency facilities."
"Take your time, Petra," Joe said. "No one's in any hurry to be a guinea pig if we don't have to be."
"I know," Petra said. "On the other hand, however, this is an ideal time to perform some preliminary field trials, and was after all the reason the drugs were sent along in the first place."
"Oh-oh." Joe's voice was so grimly dour that Jackie couldn't help but giggle. "Now she's going to experiment on us in the name of Science!"
"You need anything, Jackie?"
"Actually, yes, Brett – I realized we were all being so stupid with the linkup design. I want you to do a model and design trial assuming we're going to dock the Nebula Storm forward-points first along the axis of Odin."
The pause was somewhat longer than the expected 8 seconds. "Along the… oh, I get it!"
"Yeah, I guess we were all being kinda dim," A.J. commented. "That'll work a lot better. I guess we figure on embedding up about halfway to the main lock, then run a corridor tube out to the lock."
"Something like that. And then we rotate everything at the proper speed. Odin was designed for that anyway."
"She was," agreed Hohenheim's deep voice cautiously, "but I remind you that my ship has been put through a very great deal in the last months, and we should be very careful about forcing her to rotate in that fashion again until we have surveyed the entirety of the critical support structure. We do not wish to have half of the Odin suddenly send itself hurtling into space."
"No fear on that," Brett answered quickly (or as quickly as time-delay would allow). "With A.J.'s sensors, my modeling, and Odin's own PHM systems, we can make very sure."
"Any additional problems caused by this approach rather than the other?"
That was Madeline, Jackie thought, and then considered the question. "Umm… I don't think so. The only real problem I can think of offhand is one of the same ones we would have in the more complicated linkage designs – attaching stuff securely to that damn Vault material in the hull. It doesn't weld easy at all, and I don't think anyone's found a glue that sticks worth a damn, either."
"I'll model some alternatives," Brett said. "I'm thinking of just running clamps out to the bases of the four habitat extensions, and putting a ring behind them. It'd be a pain on EVA for whoever's doing it, but I think it'd work. We're not talking about terribly high accelerations in any direction, so structural integrity shouldn't be a big problem."
"Just make sure you model extreme cases," Jackie reminded him. "I know, that sounds like an obvious thing, but we won't get any do-overs on this. So modeling… oh, I dunno, say what happens if one of the habitat anchors gives way and suddenly we're rotating with only three of four connected? That's the kind of thing we have to be ready for."
"You're right. And believe me, I'll make sure all of you get to see the models I've done and let me know if I've forgotten anything."
"Good enough," Maddie said.
"Hey, Helen," Jackie said. "I had a thought while we were around the other side this time and wondered if you had an answer for it."
"Hold on, Jackie… All right, I've got the Locusts on hold. They're excavating something else for me now. Go ahead."
"Well, I know there's been all sorts of debate about aliens before we discovered Bemmie, and a lot of the arguments were about how and why they'd bother to come here," she said slowly."But it occurred to me that now we've got a better explanation.
"Maybe Bemmie came from Europa. That's why they were here. They didn't have to travel to the solar system because they're just as native to it as we are."
The airwaves were silent for several moments before several voices started to speak at once. "Hadn't thought of –" "Hell, that's an idea, I—" "No, I don't think –"
"EVERYONE," the amplified transmission of Hohenheim came, momentarily squelching the others, "let us speak one at a time. Dr. Sutter, the question was addressed to you."
"It's certainly possible as far as I am concerned," Helen said after a short pause. "Since the ocean here is possibly very like Earth's, and both Earth and Europa must have formed at similar times, there were billions of years for Europan life to evolve. No reason that I can think of that Bemmie couldn't have gained sentience and sapience a few million years earlier than we did."
"And that would sure explain their presence," Dan said with some excitement. "They got to their surface, saw all the other planets, and Earth would have looked like a beacon to them, I think, close enough in that you didn't have to melt your way to the surface to see the stars."
"It has an appeal of simplicity about it in many ways," agreed Hohenheim. "But I believe I heard some dissent on your end, Maddie?"
"I think that was A.J., though I have some questions on the idea. A.J.?"
The sensor expert's voice held the slight edge of pride that it usually did when he was announcing an insight. "Sorry, Jackie, but no way. And there's a reason for that which any engineer would know – or any classical student, probably."
All right, what's he getting at?
"I'm not following you, A.J., " Joe said after a moment. "At least, I'm not seeing any objection to this that's anywhere near as bad as the ones for them travelling light-years."
Got it! She felt slightly better, having just figured it out instead of having to hear A.J. explain to her the vital hole in the theory. "No chance for Prometheus, is that your point?"
"Oh, excellent, you got both references." His rejoinder wasn't sarcastic – one thing about A.J., he liked people to figure things out.
"What do you mean?" Helen asked.
Maddie answered. "It’s the first objection that came to me, too. The key to civilization as we know it really rests on two things, and one of them is the control of fire. How do you refine metal, manufacture a spaceship or tools or do any of a thousand other things when you can't build a fire, smelt ore, and so on because you're always underwater?"
"And I just thought of another," Helen said. "A more fatal one overall, actually, and I have to admit the 'no fire' objection is pretty close to fatal. Bemmie was an evolved amphibious form. But there isn't any land here."
"Oh, duh," A.J. said. "There I went coming up with the clever scientific objection and you figure out one that's so much more basic that I needen't have bothered. So that's that; they had to have evolved on a planet that, like ours, had an open water ocean and an oxygen-rich atmosphere, since all indications are they breathed air like ours, and they went from making fire to building starships, breaking the lightspeed barrier to travel across the galaxy. Or at least the local stars."
"Eh?" Jackie said. "A.J., I seem to remember you accepting – way back on Mars, after we first finished looking over the Vault – that they'd come here using some kind of STL tech."
"I did, but I've re-thunk it," he said. "These guys could come all the way to another solar system with enough stuff to set up at least one and probably two major research facilities. They had enough time and resources involved that they could end up in a major war, and someone who won could do all that and then build the damn Vault as a message … and walk off." She could see his tiny image shake its head. "No, I reverse my old pronouncement; I'll bet everything I've got that they had something that was either FTL, or that violated some other rule of our known physics enough to make travelling to another solar system no harder than travelling to another planet in this system."
"So… why didn't they ever come back here, finish whatever work the side that won was doing?" Joe asked.
"No answer to that yet," A.J. admitted, "or, rather, there's about a thousand answers to that and I haven't really got anything that gives us a clue as to which answer we want."
"Doesn't really matter now," Helen said sensibly. "What's important is we're all alive to ask the questions. And that it looks like we're going to stay that way and keep asking them a while longer."
"As long as we keep working," Jackie said, reminding herself as much as everyone else. "Horst, I think we'd better go up and start looking at the areas we're going to need to prep for Nebula Storm's lockdown."
"You and Mia had better do that," Horst said. "We need to get the first load back to Europa Base so they can build the centrifuge, and I can start bringing Odin back lots of loads of water for Odin to use. It's time to start launch prep."
She realized that he was right; if Athena was finished refilling Nebula Storm's tanks, it was time to start ferrying reaction mass from Europa to Odin. "You're right. Okay, Mia, let's get moving!"
She swung out of her chair and propelled herself quickly towards the far exit, where her spacesuit hung on velcro, waiting. We're really making progress!