CHAPTER 39.
A dull thuddoom! echoed through Madeline’s suit and vibrated in her boots as all the compressed water vapor in the tunnel abruptly vented, the momentary hurricane tearing at her and the others before turning back to essential, silent vacuum.
“We’re through!” Jackie shouted, and Maddie joined in the cheer. “Maddie, A.J.’s sacked out. Do you think—”
“No problem. Just get Athena far enough out of this tunnel so the rest of us can get out too. Then I’ll want to check the whole area’s integrity before we start faking up the atmosphere.”
“You’ve got it. Mia?”
The Norwegian engineer nodded, and she and Jackie quickly got Athena to move forward now that there was no impediment between her and open space.
Maddie bounced over to the jury-rigged lightbar which served as the communication interface and hooked in fresh power packs. “Joe?”
“Maddie!”
The instant response made her feel suddenly ten years younger. “You’re both all right?”
“For now.”
Tension returned. Joe wouldn’t say that if…“What’s the bad news?”
“Well, the good news is that we’ve got some spectacular footage and evidence of a really advanced ecosystem here on Europa,” Joe said in his usual overly-casual description of disaster. “The bad news is that the local wildlife got very frisky with Zarathustra and the lock’s gone to amber alert.”
Oh dear God. “Are you leaking?”
“Not yet, but sensors show an increase in humidity in the seal area. It’s going to leak, and it’s not going to take all that long. Now, I don’t know if the inner door will have any problems or not, but it wasn’t designed to hold water, just varying types of atmosphere, or lack thereof. I’m pretty damn sure the pumps won’t handle it. Now, the other good news is that I don’t think it’s jammed shut—I can’t test it, but all the indicators are that it should be able to open.”
She took a breath and made herself relax before she spoke again, and gave silent thanks that almost everyone else was currently resting. “Do you have a guess as to when the real leak will start?”
She heard him sigh. “Not really, Maddie. But when it starts, it will get progressively worse, faster and faster; ten atmospheres is no joke, and the seals weren’t made for it.”
“Well, it hasn’t started yet, and we’re here, so we’ll be getting you out of there as soon as we can.” She stood. “I’ve got work to do, so I’m cutting out for now. I love you.”
“Love you too, Maddie.”
She made sure the connection was off, then took the RF transmitter off her back and started it running. Slowly, the display in her VRD began to sparkle with the awakening of the Faerie Dust which was now scavenging power from the powerful transmission. “Okay, we’re in business. I’m checking the walls. Now, Jackie, you said that leaks will tend to be self-sealing?”
“With a vengeance, yes. Water vapor going out will condense and freeze almost instantly. That’s both an advantage and part of our problem.”
“I had a feeling you didn’t sound as confident lately as we did a while ago.”
“Oh, the plan sounds great on paper, but there’s a big practical problem. Brett’s models say we still might pull it off, but…”
Maddie knew that dancing around a problem was a way of trying to cushion the blow, and she appreciated the consideration…but sometimes it was like pulling teeth! “Mia, do you know what Jackie’s talking about, or will I have to drag it out of her?”
“Do you understand how a steam turbine works?”
She raised an eyebrow, thinking. Obviously this has something to do with the problem. “High-pressure steam pushes a set of blades around, condenses, gets re-heated until it boils, and around it goes again, heating to pressure, cooling, boiling…Oh, damnation.”
“Yes, I didn’t think I would need to do the full explanation. At somewhat over a megapascal, boiling point of water is about one hundred eighty C.”
She closed her eyes. What’s the point, then? But she remembered what Jackie had said. “So the water will be condensing out as fast as we make it into steam?”
“That’s the key,” Jackie said, in a tone that sounded like she was working on convincing herself. “Brett and I don’t think so. Athena is a nuclear reactor made to melt ice, and melt it FAST, and that means it can make one hell of a lot of steam. As more of the steam condenses, it will both be sealing the chamber and making it smaller, because it will mostly freeze on the inside. That will make the chamber very strong, and have lower volume, so we’re now sure it can hold the pressure. And we think that Athena will be able to vaporize water fast enough to outpace the freezing, especially since freezing releases heat—heat of crystallization—and the temperature will rise significantly, and of course because we’ll have the carbon dioxide and ammonia coming with the water.
“You can’t melt this mass of ice easily, or very fast, just from air temperature alone, so pretty soon we’ll hit an equilibrium volume and pressure will go up; water will still condense, but Athena will be throwing steam and gas up faster than it can condense out. We think.”
Madeline desperately wanted to believe this would work. “But Athena was only going through a half meter or so per minute.”
Jackie managed a grin, and in her nervousness seemed to be trying to emulate A.J. “Ahh, yes, but that was ice at almost minus two hundred, and we had to be careful because of the things we might hit on the way down. I’m not having to deal with either of those here. The ice here is almost at melting point already and we’re going to drive her around boring holes as fast as she possibly can go, pulling her up when she gets near the surface—until we get close to the right pressure, and then we’ll let her go down and vaporize the water as it tries to get past her. I figure if we brace her really well in a bore she could hold something close to four atmospheres back by herself, so if we can get up to point six or point seven megapascals we can use the ocean itself to push things the rest of the way.”
Madeline was already working the scenario over in her head—she wasn’t an engineer as such, but rule-of-thumb estimation and jury-rigging was something of a must-have skill in her old profession. Jackie’s trying not to emphasize just how hard this is going to be. I can’t blame her, really. We need to get the story straight for everyone else, because we can’t have doubts slowing us up.
“A small chance is better than no chance, Jackie,” she said finally. “I’m not going to describe the problem to Joe and Helen. Joe might—probably already has—guess at the challenges we’ll be facing, but I’ll let him decide if he wants to drop it on Helen; I won’t tell them myself.”
Jackie nodded, then glanced at her. “You didn’t sound all that relaxed before we gave you the bad news,” she said. “What’d Joe tell you.”
Maddie summarized the situation. “So we have even more reason to hurry.”
“Then it’s time to sound the starting bell,” Mia said. “General! We are ready to begin! It is the last stretch of this race, and we need everyone on the track!”
Madeline looked down, where her husband and friend lay suspended in pitch-black water. Somehow, this has to work. Somehow we will make it work.