Portal-eARC (31 page)

“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.

Chapter 40.

“They should have started trying to break us out by
now
,” Helen said. She knew it sounded like she was whining, but it had been more than two weeks since they had been stuck under Europa’s steel-hard ice. Quick sponge baths, especially ones taken in ten-degree C air, did not make up for lack of even the Spartan cleaning regimen available in
Nebula Storm
, let alone the comparative luxury of the hot showers in Europa Base.

And
Zarathustra
was starting to
stink
as well. The air was okay to breathe, but she suspected that being suspended vertically was impairing the plumbing.
If there’d been more of us, I bet the tank would be overfull by now…and we’d have a pool of something unmentionable on the bottom.

“It’s not all that easy, you know,” Joe said. “There’s a lot of space to fill.”

“I’m not entirely innumerate,” she snapped, then closed her eyes. “Sorry, Joe. I shouldn’t take it out on you. But I could look up a few things, and make a few guesses, and things don’t make sense. When you turn ice to steam you get about sixteen hundred times as much gas as you had water, a little less with ice because it expands a few percent. But even if the area they had above was a box sixty meters on a side and twenty high—and I know it’s not, it’s more a cut-off triangular pyramid, which has less volume—that’s only about 45 cubic meters of water they have to vaporize to fill it. Even at its old speed
Athena
should have gone through that in an hour and a half.”

Joe grinned, but there was a sad edge to the grin. “That’s not bad back-of-the-envelope guessing there. Actually, if all your principles held, they only needed about fifteen cubic meters. But…they don’t hold. First, a lot of it’s freezing out as they go, so they have to replace it. Second, that volume’s at standard temperature and pressure. We have to build the pressure from
nothing
, and then keep going. Remember, ten times the pressure, which means we need a
lot
of melted ice.”

A low humming rumble transmitted itself through the air as she absorbed that.
Athena
’s violent conversion of ice and water to steam caused vibrations throughout the ice that echoed into the ocean. The noise grew louder as the nuclear melt-probe drove downward, then stopped for a short time as the probe was pulled back up and repositioned, to start faintly again and grow louder. So far she hadn’t seen any new visitors, but the longer that utterly-unknown noise went on…“You’ve known this for a long time.”

“Figured most of it out as soon as I realized what the situation was, yeah. And I didn’t tell you because there wasn’t much point.” Joe shrugged. “Now that you’ve asked—the lowdown is that I’m giving us a one-in-five they can pull it off.”

She nodded. “Better odds than I guessed.” She looked at the control panel. “Have we got a leak yet?”

Joe studied readouts on the panel and in his VRD. “Not yet, but…I’m guessing soon. No liquid water, but the humidity keeps going up in the seal area.”

“How soon is soon?”

He shrugged. “If I plot a rough graph…maybe a day or two. Once the leak starts, I think we’ve got another day before it becomes critical for the inner door. If the inner door can hold the pressure, then we may be fine.”

She looked at him, and could see even through the helmet that Joe’s usual casual expression was absent. “But you don’t think it will.”

“No. If you want my honest opinion…?”

“Might as well.”

“I figure the door will blow right in as soon as the pressure hits six or seven atmospheres. Then we die very fast.”

She nodded again.

For a long time neither of them said anything. The buzzing hum of
Athena
ceased, then faintly restarted. She chuckled suddenly.

“I could use a laugh. What’s so funny?”

She looked upward, grinning faintly. “I just realized, it must look like Swiss cheese, or a beehive, by now. All those holes spaced all over the floor…”

Joe chortled. “I’ll bet it does. And you’d better watch out where you walk now.”

She glanced down. No sign of movement below. She watched a few minutes, but saw nothing yet.

More minutes passed.

“Joe,” she said finally.

“Yes?”

“We’ve done a hell of a lot, haven’t we?”

He snorted. “Let’s not start the pre-death farewell yet.”

“I can’t help it; I’d like to be ready.”

“Maybe I shouldn’t have told you the odds.”

She shook her head. “Joe, I wanted to know the truth.”

“Well, maybe I should have told you the
other
odds.”

She stared at him, puzzled. “
What
‘other odds’?”

He pointed up. “Up there? That’s Madeline Fathom. Madeline Fathom
Buckley
, a woman so far out of my league that I didn’t even realize just how far out she
was
for years. But for some reason she took a hell of a liking to me. She’s crazy enough to
marry
me.

“She’s also just crazy enough to figure out some way to rescue us, because that’s exactly what she
does
. So I figure that our
real
odds are pretty damn good, because I’m down here, and she’s up there, and that’s
not
the way she wants it.”

She laughed suddenly, and gripped his hand. “I guess you’re right.”

“Damn straight. She held up
Mars
when it was trying to collapse on us, what’s a meter or two of ice?”

Without warning, a thundering thrumming noise vibrated
Zarathustra
like the string of an enormous bass, a sound like a jet in an earthquake.
“What the—
”

At the same time Joe let out a whoop that almost deafened her, even over that frightening noise.
“That’s it!”

“What? What’s it?” She couldn’t imagine what could be making a sound like that, but Joe obviously knew.

“
Athena!
They’ve built up pressure! They’ve let her break through and take on the whole damn Europan ocean as a feedstock!” With a little difficulty, Joe spun his seat around in a victory circle. “The odds just went way, way up, like one in two now. They don’t have to move Athena, and the fact that we’re still
hearing
that beautiful, beautiful noise means that the pressure of the ocean hasn’t kicked
Athena
back up her bore. She’s taking everything Europa has and vaporizing it out the back.”

Lights flashed. “Joe?”

“I hear it, Maddie! Good news!”

“
Very
good news, Joe!” Helen could hear tentative, strained relief in the other woman’s voice. “So far she’s holding, and Jackie says if she stays put another few minutes she’ll be confident that nothing’s going to move
Athena
out of position. You can almost
see
the pressure rising.”

“Which leaves you one problem.”

“We’re working on it. The solution may involve explosives.”

“With you involved? I’d be disappointed if it didn’t.”

Helen glanced down as the two continued their conversation, and dropped carefully back down to the rear window. With this new sound, who knew what might happen?

And there it was. A shimmer in the depths, almost invisible.
Please, God, not that same thing. Let it have learned its lesson.