“Get out? Surely that stuff is not stable.”
“Probably not. Especially with the weight of this water behind it. If it collapses that would solve the problem.”
“What about you?”
“Yeah, well, life’s full of little trade-offs.” She edged the boat into a small backwater between a downed tree and a boulder. “Okay Jenn, get back here and take the control.”
Singh clambered back over the bench seat and sat down on the floor of the boat beside Sawyer. “Okay, I’ve got it.”
“All right, hold it steady while I climb out. I’m not going far. The water’s still rising so keep an eye on the shoreline.”
“Okay. Be careful.”
“Always.” Sawyer took hold of a limb poking up from the downed tree and tugged on it. It held. Using that for balance she got up into a half crouch and stepped over the side of the boat, her foot squelching in the mud of the slope. She took a few experimental steps, then slipped and fell to one knee. “Damn it.”
“Are you all right?” Singh called.
“Yeah, it’s just a bit slick. With this kind of soil I’m not surprised it slid. I’ll be fine.” She dropped the rest of the way to her hands and knees and crawled up the low slope, using her hands to grab onto rocks or tree limbs that looked well enough anchored to hold. As she reached the crest, a meter or so above the water line, she stopped and carefully stood up.
“What does it look like?”
“Dark, I should have brought a light.” She took a few steps in either direction. “Hard to say. It doesn’t look like it gets any higher down the valley, but it does extend a ways.”
“Here, have a light.” Singh had retrieved a flashlight from the boat’s kit. She turned it on and tossed it to Sawyer, who missed the catch. Sawyer’s visor was fogging up with the cold and humidity. The light plopped into the mud about a meter away.
“Nice catch,” Singh said.
“Thanks.” Sawyer picked it up and smeared the mud around trying to wipe it off. Dang it! She pushed back her hood to better see what she was doing, ignoring the water streaming down on her head. Finally she just held the flashlight out in the rain for a few moments; the downpour cleaned it off quickly. She shone it over the ground, up and down the slope. Mud and broken vegetation as far as she could see, but in this downpour that was only a few meters. She couldn’t see the far edge. She turned to look back at the river and Singh in the boat. “I’m going to see how far it extends.” She turned again and slogged forward. Why couldn’t they have landed in a nice dry desert?
She took a few steps up the muddy slope, then shivered and cursed as a hoodful of cold rainwater poured down the neck of her biosuit. She’d left the hood down so she could see, and now it kept filling with water and dumping down her back every time she bent over. If this keeps up I’m going to drown. A fine end for a geologist four light years from home. I’m not even surfing. She never had liked the damned suits.
She trudged further over the slick, soggy debris. In the worst case this could extend for a mile or more down the valley, in which case the landing field was on its way to becoming a lake. She hoped the crew back at the Chandra had a contingency plan figured out.
∞ ∞ ∞
“I hope Sawyer finds the blockage easy to clear,” Darwin said. “We’re running out of ideas.”
They already considered and discarded wrapping the bottom of the ship in plastic sheeting to keep it dry. They didn’t have anything big enough, although given more time than they had they might weld something together out of the supplies they had. Finley had suggested running the engines at idle to keep the water blown clear. Patel had blanched at the suggestion and categorically refused.
“What if we freeze it? Create an ice dam around the ship?”
“Freeze it how?”
“We’ve got a tank full of liquid oxygen, we ought to be able to rig something.”
“There is only a small spigot valve to tap the tanks, which is adequate if we only need a couple of liters, but the flow rate is too low to freeze this quantity of water.”
“What about just pumping it through the engines? That’d be a high flow rate.”
“That is almost as bad as just firing the engines,” Patel said. “Also we would have to override all the sensors and software modules designed to prevent that sort of thing.”
∞ ∞ ∞
Sawyer slipped again, scrambling for a handhold on a tree limb jutting out of the muck. She must be almost to the other side, surely. She paused to listen. Over the steady roar of the falling rain, was that a rumbling? The storm surge would have swept the ocean up the river, and the waves would be pounding hard, but the sound which Sawyer wasn’t even certain she heard could as easily be distant thunder. But the slope seemed to be leveling.
A few meters further on and she was convinced she was on the back side. The ground sloped away at a steepening angle, and in the beam of her flashlight, Sawyer could just make through the rain a tree trunk. It looked to her more like the mud and debris and piled against the trunk rather than carrying it here, that was a good sign. The ocean was further away, wave action wouldn’t be eroding this slope any time soon.
She’d better let the Chandra know.
∞ ∞ ∞
“Chandra this is Sawyer,” came her voice over the radio.
Darwin keyed the microphone. “Go ahead, how does it look?”
“Could be better, could be worse. Looks like the water has about another meter or so to rise before it tops the dam formed by the slide.”
Darwin, Finley and Patel looked at each other, grim. The water was already starting to lap at the lower footpad, another meter would put it over the heat shield, more than that and it would be splashing against the engine nozzles.
“And the good news?” Darwin asked.
“Who said there was good news? But the dam isn’t that thick, about fifteen to twenty meters, it’s not like it fills the valley.”
“We can’t take another meter of water here. Half that and it’ll be starting to splash the heat shield. Patel says that’s not good.”
“Oh, crap. We’ll have to cut a trench through the top of the dam then. This stuff is pretty loose and slick, once we get the water flowing through it the current should wear it down pretty quickly and the water will stop rising.”
“Great, you’ve got two hours to dig a trench a meter deep and ten long. Did you bring a shovel?”
“No, but I’ve got seismic charges back at the ship, that’ll help. We’re on our way back now.”
“How many will you need?”
“Probably more than I’ve got. They’re for sending shock waves, not mining. If there’s something else we can use for explosives, get that together too.”
“Okay. See you soon.” Darwin clicked off the mike and turned to the others. “Finley, do you know where the seismic charges are stowed?”
“Yeah, I’ll get them.” He got up to leave the cabin.
“Okay, and if you can think of anything else. . ..”
Finley paused at the hatch, turned, and shook his head. “I don’t think anyone else had much call for explosives. I’ll see what’s down there.”
“Maybe we can improvise,” Darwin said as Finley left. “Ganesh, any ideas?”
“The ship itself has pyrotechnic components but they’re all built in.”
“What about the propellants?”
“LOX, methane and hydrogen. Sure, you could make a pretty big bang with those but I can’t think of any way to transport them. Not the hydrogen, anyway, it would boil off. The LOX perhaps, we could use one of the nitrogen Dewars for that.” The biology lab kept liquid nitrogen on hand to flash-freeze specimens. “I suppose in theory we could mix methane and liquid oxygen, it will form a kind of slush as the methane freezes, but I am thinking it would be too sensitive.”
Darwin couldn’t imagine that being stable. “I think it would detonate if you thought mean thoughts at it.” He shook his head. “LOX is a strong o
xidizer, there must be something else we can react it with.”
Finley had just come back into the cabin. “What’s this about LOX?”
“Any ideas on improvised explosives?”
“LOX and charcoal will work. We can scrounge charcoal from the campfire . . . oh, it’ll be waterlogged.”
“Will that matter?” asked Darwin.
“I don’t know, but I don’t see how it will soak up the LOX if it’s wet, it’ll just freeze.”
Patel spoke up. “The life support system uses charcoal canisters to scrub organics from the air. How much would you need?”
“The stuff is about the same strength as dynamite, from what I remember. I don’t know, a few kilos?”
“Very well, the canisters are two kilograms each. Two are used, we can spare another. Six kilos?”
“Sounds perfect,” said Darwin. He did some quick mental math. They’d need twice as much oxygen as carbon, and liquid oxygen was slightly denser than water. A bit over half of one of their 25 liter tanks, then. “Ganesh, you get the charcoal canisters. I’ll get the nitrogen dewar from biology. Then I’ll need your help to tap the main LOX tank.”
∞ ∞ ∞
In the fifteen minutes it took Sawyer and Singh to return in the boat, Darwin had shown Finley how to work the valves on the dewar fill and drain mechanism to squirt out the remaining liquid nitrogen – the same steps Finley would use with the oxygen – and with Patel’s help, had filled the tank about two-thirds full with LOX. Probably violating all kinds of protocols, but since liquid nitrogen had a tendency to condense oxygen out of the air anyway, the dewar was made of oxygen-safe parts.
∞ ∞ ∞
Ten minutes after that, Sawyer was headed back in the boat toward the landslide area. Finley was with her this time, to help her set the charges.
“Have you ever done this before?” Sawyer asked him.
“What, the LOX-charcoal explosives? Actually no, but I’ve read about it.”
“Oh, great. Don’t blow us up.”
“That’s why we’re not mixing it until we get there. We’ll dig a hole, dump in some charcoal, pour in some LOX, and then it’s good to go.”
“How sensitive is it?”
“Depends on the charcoal and what other organics are in it. This stuff is pretty pure, even the used canisters, compared to burnt wood. We should be okay.”
“Will we be able to set it off?”
“Oh yeah, just hit it hard enough. If we spread the seismic charges out that should do it. We should wire them to all go off at once, though.”
“That’s what I was figuring on,” Sawyer agreed.
“I just thought of something.”
“What?”
“It’s pouring with rain; the ground is soaking.”
“Oh, you noticed that, did you?”
“No, I mean when I dump the charcoal in the hole, it’s going to get wet. It’s not going to soak up the LOX before that freezes.”
“Ah. Hang on.” Sawyer patted at the pockets of her BIG and unzipped one. She reached into the pocket and pulled out a handful of transparent plastic specimen bags. “Here, put the charcoal in these, then put them in the holes.”
“How do I mix the LOX in?”
“I dunno, leave the top of the bag open. You can figure it out while we dig the holes.”
“Okay. We’ll plant the seismic charges first, they’re stable.”
“Right. And it looks like we’re here.”
The water was now about half a meter from the top of the slide, which actually made things easier as they wrestled the heavy dewar, now full of liquid oxygen, out of the boat and onto the mud and debris pile. Finley began unloading the other gear, the seismic charges, charcoal canisters and detonator wires, while Sawyer set up her geologist’s coring drill.
“Okay, we’ve got twelve charges so we’ll put them about a meter apart, then a half-kilo of charcoal midway between each? Will that work?”
“I can’t be certain. But the ground is wet, that should conduct the shock pretty well.”
“Crap, it would be nice to know for sure. Too bad we don’t have any detonating cord. All right, the first pair of holes I’ll put closer together. Maybe it’ll help focus the blast.”
“But I wouldn’t worry too much; seismic explosives are designed to give a sharp hard pulse, makes the seismology easier.” Sawyer started the coring drill. In the mix of muck and gravel it dug in quickly. She only needed to go down a meter. She pulled the drill out. “Okay, first hole’s ready. You set the charge; I’ll get the next hole.”
Finley took one of the blue plastic-jacketed sticks and screwed a detonator onto the threaded end. He lowered it into the hole, which was already starting to fill with water and mud, leaving the wires trailing out. He pushed several handfuls of mud and gravel into the hole on top of the explosive. The loops of detonator wire he draped over a protruding tree branch to keep them from disappearing under the mud. By the time he’d finished, Sawyer was ready with the next bore hole.
They repeated the process across the width of the slide, until the last of the seismic charges was placed. As he went, Finley had been gathering grapefruit-sized boulders whenever he came across one.
“What are those for?” asked Sawyer.
“To cap the holes with the charcoal/LOX mixture. I don’t want to just dump mud down on top, that might set it off, and I don’t want the rain getting in either. After we pour in the LOX I’ll just set one on top of the hole.”
“Good thinking. Okay, I’ll work my way back drilling those holes now.”
While Sawyer was drilling the first of the holes for the charcoal Lox mix, Finley went back and wrestled the LOX canister to the other side of the landslide.
“Tell you what, I’ll just cap these holes now and wait until you’re done drilling before putting anything in them. No sense both of us being at risk.”
“Just how sensitive is that stuff?”
“I wish I knew. Anyway, like I said, no sense both of us being at risk. Keep drilling, I need to fill these bags with charcoal.”
“Okay.”
As Sawyer moved back across the slide, drilling boreholes between where the wires to the seismic charges snaked out of the ground, Finley pried open the charcoal canisters and began scooping black granules into the plastic specimen bags, keeping everything sheltered from the rain as best he could with his body.
That done, he called over to Sawyer. “How is it going?”
“I’m just on the last hole now. Did you figure out how you’re going to mix the LOX in?”
“Yeah, I swiped one of your drill tubes.”
“Ah, clever. That should do it.”
The coring drill that Sawyer had been using was designed to drill a considerable distance, too far to be practical with a one-piece drill bit. Just like its bigger cousins, sections of drill tube could be added at the top as the hole was dug deeper. There’d been spares of these with the drill, Sawyer wasn’t going deep enough to need them, but they were perfect for what Finley needed.
He dropped a charcoal bag into the first hole, gently pushing it into place with the tube. Then he pushed the tube hard, twisting as he did so, to tear the top of the plastic bag. He hadn’t sealed it, but this would make sure that the LOX could penetrate. Leaving the tube in place, he raised the dewar—it was awkward and he struggled a bit to get the mouth of the nozzle lined up with the tube, then pushed the valve lever to pour what he estimated was liter of pale blue LOX down the tube. A cold fog flowed around the drill tube and up out of the hole around it. Finley set the container down and gently began withdrawing the tube from the hole. It was stuck. He tugged harder, highly conscious that the bottom end was now sitting on over a kilogram of shock sensitive high explosive. It didn’t move. He bent down to peer into the hole, blowing the cloud of condensation away. The drill tube was covered in ice. Of course! The LOX had chilled the tube and the rain had frozen to it. Where it was touching the side of the hole, the mud would have f
rozen to it. Great.
“Sawyer, how many spare drill tubes do we have with us?”
“Two more. Why?”
“Damn. This one is frozen to the hole. I don’t want to get violent with it now.”
“Do you need to use the tube to pour the LOX?” If they pulled the drill tube out before pouring, they could make do with the remaining drill tube.
“I guess I don’t have a choice. Okay, bring one up.” Finley picked up the small boulder he was going to use to cap the hole and reached to put it on top of the drill tube. He was just about to set it down when he stopped himself. That shock would transmit to the bottom of the tube. It might not be enough to set off the explosive, but. . .. He gently set the rock back down on the ground, took one of the unused specimen bags and slipped it over the end of the tube.
Sawyer was already at the next hole with another drill tube. “Look, it’ll go faster if we both work. Give me the bags, I’ll put the charcoal in, rip the bag, then go on to the next hole while you pour the LOX.”
“But—”
“Never mind buts. The water’s rising faster, it must be almost up to the heat shield back at the ship.”
“Okay, but this stuff is sensitive. And depending on what other organic stuff is in the hole when I pour in the LOX, it could go off right then.”
“Duly noted. Let’s get moving.” Sawyer dropped a bag into the hole, tamped it down with the pipe, gave it a twist for good measure, and withdrew it. “All yours,” she said to Finley, and moved on to the next one. Finley knelt down beside the hole and reached for the valves on the oxygen dewar.
∞ ∞ ∞
In the control room of the Chandra, Darwin, Patel and Singh watched one of the monitors. The screen showed the underside of the ship, a shot from a camera on one of the landing legs. The water pooled under the heat shield.
“I am starting to wonder if it is worth the risk to fire up the engines,” Patel said.
Darwin looked at him. “Are you seri—” He was cut off by an ear-splitting CRACK followed by a rolling, booming echo. There had been no lightning flash.
Alpha Centauri: First Landing (T-Space: Alpha Centauri Book 1) Page 17