Déjà Doomed

by Edward M. Lerner

  “Or the ship’s intelligence, always assuming there is one, sabotaging us again.”

  “Or that,” she agreed. “Or maybe it was as simple as Yevgeny falling asleep.”

  “I don’t believe that last one.”

  “Truthfully? Me, either.” She grimaced. “What does it matter?”

  Somehow, it did. Never mind how impossible it seemed that they would ever know the cause of this latest disaster.

  Marcus changed the subject to something more urgent. “Without an airtight compartment, we can’t get Yun out of his counterpressure suit and set his arm.”

  She looked away.

  “What?”

  She mumbled, “Would medical attention now do him any favors? Maybe letting him go, even helping him along, would be kinder.”

  Yun coughed. “It probably would be kinder, but I still would rather you not.”

  * * *

  The ship carried two emergency shelters in its inventory. Inflated, each was a hemisphere five meters in diameter. Nowhere aboard would accommodate an igloo, and the outer airlock hatch had been warped beyond operability.

  They had not needed explosives to open the Titan facility—but they needed some now. With a boom felt but not heard, the jammed hatch went flying. Sunlight flooded in. Marcus stuck out his head, half expecting to find Rescue One (and how ironic that name had become!) adrift, rebounded from the asteroid, unbound by its pathetic gravity. Instead he saw a craggy surface scant meters below the hatch. The ship’s crushed nose had been driven into the shaft.

  “We’re still on the Hammer,” Marcus reported. Which gave him hope, however slim.

  He lobbed a magnetic grapple to the surface, tugged the line to confirm the grapple had a secure grip, and stepped out. While Katya shuttled supplies toward the airlock, Marcus circled the wreck, hunting for someplace flat—and offering protection if the ship exploded again—to deploy the igloo. He chose a shallow crater a good hundred meters from Rescue One, and almost one hundred eighty degrees around from the airlock.

  The crater floor, everywhere he tested, was too hard to pound in stakes; he glued stakes down instead. Clumsily, with gloved hands, he tied the shelter’s tethers to the stakes and opened the valve on the inflator gas bottle. As the shelter assumed its familiar igloo shape, the Sun glittering off its flexible layer of dark solar cells, an odd wave of nostalgia washed over him. The worst he’d had to face in a lunar igloo was sneezing.

  Marcus returned to the ship. “Katya, start handing down stuff.”

  And out stuff came. Oh-two tanks. Water tanks. Assorted tools. First-aid kit. A sack of clean clothes. Hard-shell suits. A stack of spare datasheets. A double armful at a time, he relayed supplies to the shelter. Until, clutching to his spacesuit chest a sack overstuffed with canned and freeze-dried rations—

  One careless misstep launched him into space!

  Marcus shoved away the sack. The recoil sent him back toward the surface. Also, into a spin. He ricocheted without planting a magnetic sole anywhere it would do any good. His heart pounding, he arrested his spin with gentle puffs from his gas pistol. Longer puffs brought his drift to a halt and returned him safely to the surface.

  For his remaining trips, Marcus carried less in each load and shuffled back and forth at a snail’s pace.

  After cycling the final load through the igloo’s airlock, he returned to the ship. “Now help Yun down.”

  Yun, after one ragged gasp, bore in silence what must have been excruciating pain. Katya eased herself down after. All three tethered together, and with Yun’s one good arm draped across Marcus’s shoulder, they made their way to the shelter.

  They had to cut Yun free of his counterpressure suit. With his helmet removed, at each nudge and jostle they heard the sharp breaths he forced between clenched, grinding teeth. Apart from the one first-aid kit, their medical supplies had disappeared, whether gone up in the short-lived flames or blown out through rents in the hull. At least the bleeding had stopped.

  “The others?” Yun whispered.

  With tears in her eyes, Ekatrina shook her head.

  With Velcro strips they secured Yun to a cot. They started him on antibiotic pills to counter whatever pathogens had entered the wound where jagged bone had pierced his flesh. As gently as they could, with no painkillers to offer but ibuprofen and aspirin, they began to splint the arm above and below where a jagged bone end protruded. Yun, mercifully, passed out.

  In the middle of the procedure it hit Marcus: a second broken arm. Twice now he had denied Donna’s help to a patient. He muttered, “Karma’s a bitch.”

  “Are you all right?” Katya demanded.

  “Yeah. I just imagined Donna saying, ‘I told you so.’ ” He shook his head. “Yun’s condition notwithstanding, I’m glad she isn’t here.”

  “There is little she could have done.” Ekatrina sighed. “Other than fail, and die, along with us.”

  “Are you sure? About failing, I mean?”

  For long seconds, under lowered brows, she stared at him. “Even if the fusion reactors are not a total loss like the main drive, Ilya never found a way to coax a big explosion out of one.”

  It was not pretty, but they got Yun’s injured arm splinted, bandaged, and in a sling.

  “Why not?” Marcus asked.

  “Why not, what?”

  “Why can’t we get a big explosion out of the reactors?”

  “The reactor fuses tiny liquid-helium droplets. Overriding the injector controls to send in droplets faster than intended will not make an explosion. At most, parts of the reactor will overheat and melt. More likely, extra droplets will sail through untouched, because the lasers won’t be ready to fire at them. Alter the fuel injector to make a helium droplet larger than intended, and the lasers will lack the energy to compress or heat it sufficiently. You get no fusion at all.” She caught herself gnawing on a fingernail. “I thought I had overcome that bad habit years ago. Well, I won’t have it very long.”

  “You’re clever. You’ll come up with something.”

  “Ilya could not! How will I? I am no physicist.”

  “Yun is.”

  She looked at Yun, and sighed. “I like him, which cannot be a surprise. He is charming and clever. But he is an astrophysicist. Ilya once told me that is pompous for astronomer.”

  “I am aware, Katya. I’m married to an astronomer.” Whom I have failed.

  Ekatrina looked away. “I mean no disrespect, to your wife or Yun.”

  Marcus turned to an unexpected soft chuckle.

  “None taken.” Yun had come to. Using just his good arm, he was struggling to undo the Velcro strap around his chest and sit up. “Well, perhaps a little about ‘pompous.’ But charming and clever? Those, I accept.”

  “When you two have finished flirting,” Marcus said, “just maybe I have an idea worth discussing.”

  Chapter 58

  Over cans of self-heating beef stew, in the cozy confines of the igloo, Marcus laid out his latest (harebrained) idea. “The ship still has lots of water. I saw one battery bank, and there may be more, that didn’t short out, and maybe we also have the fission reactor, for electric power. So we can make LH2 and LOX.”

  Liquid hydrogen and liquid oxygen.

  Ekatrina gave Marcus a puzzled look. “I cannot imagine mere thrusters moving the Hammer. Assuming any of them still even function.”

  It paid on occasion, Marcus thought, to be a generalist. “Of all chemical rocket fuels in common use, LH2 has the highest specific impulse.” Thrust produced per unit of mass. Efficiency. “Which is to say LH2 and LOX combine explosively.” While producing, apart from lots of energy, only water vapor and oh-two. As much as ecologists could like any rocket technology, they liked this one. “As early experiments with the combo demonstrated all too catastrophically.”

  Yun smiled. “A large chemical b
last, then. Fill the ship’s tanks, and blow it up.”

  Marcus nodded. “That’s the plan.” Such as it is. “Will it be enough? I don’t know. But we were very close to success. Maybe with one more hard shove ….”

  Yun scratched inside the sling using his good arm. “Blow up the ship? Perhaps we should, if it can no longer fly. First, let us be certain that such drastic measures are necessary.”

  Marcus blinked. “We had, what, a half hour or so of pushing left to go? That was your number, Yun.”

  “An estimated half hour. I could bore you with details of my calculation, or the error bars on almost every input parameter to the calculation. How much stress the hull would bear, and how cautious Yevgeny would be in pushing the Hammer, are only two.”

  “Yun? What are you saying?” Ekatrina asked.

  Yun reached out to give her right hand a squeeze. “That the thrust duration I specified was at the conservative end of my estimate. We may already have succeeded.”

  “May,” Marcus and Ekatrina said together. From her, it was hopeful. From him, skeptical.

  “May. And no, I won’t offer a probability. Not yet.” Yun looked wildly around the igloo, his voice rising in panic. “My datasheet! I must have it! It has the Earth ephemeris data I’ll need, plus orbital-mechanics algorithms that would take me days to reprogram from first principles. It was in a pocket of my utility belt.”

  Marcus extracted the belt from the cut-up remains of Yun’s counterpressure suit. He unzipped belt pockets until he found a much-folded datasheet. “Here. Now can you give us a probability?”

  “Thank you. But I still cannot give an answer. Not until one of you takes some sightings for me.”

  Marcus looked down at the tepid, congealed mass his dinner had become. An unenthusiastic stir did nothing to improve its appearance. It was just as well he had no appetite. “The telescope is gone.” Literally. Anything remaining of their telescope, or the ship’s radio and radar, for that matter, was in the ruin rammed down the access shaft into the Hammer.

  “That is unfortunate.” Yun frowned, concentrating. “We will have to manage with a datasheet webcam, which will need long exposures to register any stars. Even without the Hammer’s rotation to blur the images, those won’t be as accurate as proper sightings. Oh, and be sure those images are time-stamped.

  “I will need shots taken in several directions to get a fix on our current position. If one of you would recognize a few major constellations, I can explain where to shoot.”

  To Marcus’s way of thinking, constellations were arbitrary and ridiculous. That had not deterred Valerie from wanting him to learn them. So he had. Wives have prerogatives. “No problem, Yun. I’ll take care of that. And Katya …? While I’m outside taking pictures, I’d like you to return to the ship. See what, if anything, needs doing if we are going to produce LH2 and LOX in bulk.”

  * * *

  Abruptly, Yun’s frantic tapping and swiping stopped.

  Marcus read the apocalyptic conclusion in a crestfallen expression faster than Yun could look away from his datasheet. In that instant, the temperature inside the igloo seemed to drop ten degrees.

  “Sorry,” Yun said. “We did change the Hammer’s orbit, but not quite enough.”

  “Are you sure?” Ekatrina asked.

  Glumly, Yun nodded.

  It would be so easy to abandon hope, Marcus thought. But it wasn’t just him. It wasn’t just the three of them. “Right, then. On to blowing up the ship.”

  Ekatrina looked helplessly to Yun. “You are the math wizard. Will this explosion be enough?”

  Yun shrugged.

  “I didn’t hear no,” Marcus said.

  “Or yes,” Yun snapped.

  Marcus stuffed his hands into his jumpsuit pockets. “Walk us through it.”

  Dejectedly, Yun did. And as tenaciously, Marcus countered—as best he could—Yun’s objections.

  Yun: neither liquid oxygen nor liquid hydrogen by itself would burn, much less explode. First, the liquids had to be released.

  Marcus: the ship is in direct, unfiltered sunlight. What about switching off cryo-cooling, and letting the temperatures within the tanks rise? Maybe even rig heat lamps to speed the process? As warming liquid began turning to vapor and the internal pressure increased, wouldn’t the tanks rupture?

  Yun: to get a decent explosion, the remaining liquids also had to vaporize.

  Marcus: don’t most liquids boil readily in a vacuum?

  Yun: then the gas clouds need to thoroughly mix.

  Marcus: first thing, why don’t we weld patches over the engine-room leaks? Containing the gases will allow them to mix.

  Yun: a spark or other ignition source coming too early would mean a fizzle: a minor explosion dispersing liquids that had yet to boil and gases yet to mix.

  Ekatrina, beginning to look hopeful, joined in. “Put the ignition source—an electric blasting cap, say, and a length of detonating cord wrapped at several heights around the engine room—on a timer. That will give the gases ample time to mix.

  Yun shrugged. “That is a complicated scenario. Much could go wrong.”

  “And if all goes well?” Marcus countered.

  “A major explosion,” Yun admitted. “On the scale of chemical explosions, that is.”

  “And it might do the trick?”

  “The trick? Oh, give the Hammer enough of a final push.” Yun shrugged. “Maybe. There are too many variables. I would not give you long odds.”

  Ekatrina raised an eyebrow at Marcus.

  And what were Earth’s odds at the moment? “We’ll give it a try,” Marcus answered her.

  * * *

  While Ekatrina continued prepping the wrecked vessel for its explosive finale, Marcus offloaded supplies. He, too, meant to live long enough to know whether they had succeeded.

  His collection kept growing: more rations; a portion of water for drinking; an assortment of electronic spare parts, it not being impossible that Katya could yet assemble a radio; fuel cells, to boost its transmission if she did; a 3-D printer, whose only intact feedstock reservoir held polyethylene; their remaining igloo, not yet inflated; and some of the remaining explosives. As for that last item, Marcus had no purpose in mind—except that, apart from the charges to be used to trigger the LH2/LOX blast, high explosives left aboard struck him as imprudent. Between the damaged state of the ship, and the hostile AI that might still scheme in silence, who knew what might set off a premature detonation?

  As Yun had made so clear, everything had to go just right—and very damn soon.

  With a heartfelt curse, after almost burning off a hand with her oxyacetylene torch, an exhausted Ekatrina announced a breather from welding bulkhead tears in the engine room. Marcus dragooned her into helping offload the “portable” fission reactor. Leaving uranium to become radioactive shrapnel also seemed like a bad idea. In the Hammer’s negligible gravity, the reactor weighed next to nothing—but neither gravity nor its lack had any bearing on mass and inertia. Even working together, getting the reactor out through the airlock was a bear.

  Harder, in a far more intimate way, was carrying out Ilya’s tarp-wrapped body. Yevgeny’s remains must stay: they were inaccessible absent an industrial-strength hydraulic jack, and in any event unrecognizable. Then, in speechless sadness, Ekatrina returned to her task of prepping the big explosion, and Marcus to his stevedore duties.

  Alongside their inflated shelter, supply dumps slowly grew. A tarp, secured to the Hammer’s surface by magnets, held each pile in place.

  When Marcus popped into the shelter to check on their injured colleague, he found Yun looking downcast. No, miserable. Marcus removed his helmet and set it aside. “What is it?”

  “I am ashamed,” Yun mumbled. “Since the accident on Rescue One, what have I done? Found fault with your ideas, and Katya’s. Lolled here, useless, wh
ile you two could have used my help. Moped here, rather.”

  “You’re here because of a serious injury. That’s no one’s fault. But as for moping ….”

  “Yes?”

  “That was your choice.”

  Yun jerked back as if slapped. For long seconds, he was silent. “What can I do?”

  “Keep thinking,” Marcus said. “We’re in a shitload of trouble here. We need every bright idea we can get.” He grabbed his helmet, twist-locked it into place, and went to see what, if anything, he could do to help Ekatrina.

  * * *

  Marcus and Katya worked nonstop for two days prepping the ship to explode, and unloading anything both portable and useful. The sooner the blast, the more precious seconds the Hammer’s slightly altered path would have to diverge from Earth.

  Then it was on to another arduous job.

  “You’re sure about this?” Marcus knew the answer, but asked anyway. He wanted to distract Yun. Getting stripped down to skivvies and into a hard-shell suit in this insignificant gravity, even with help, was tough for anyone. Doing it with a broken arm splinted by amateurs? That had to be torture. “We can’t stay here?”

  Here was their igloo.

  One of the men moved wrong—again—and Yun winced. He somehow managed to morph a clenched-jaws “Ungh” into “No-o.”

  “Because?”

  “Because …” hissed between clenched teeth, “this is too close. Yes, the igloo is in a crater, but the top of the dome rises a little above the rim.”

  “And?”

  Yun managed a sickly grin. “Your distractions are transparent, and your bedside manner is terrible. Also, you are an oaf. Why could I not have Katya helping me?”