Analog SFF, June 2006

by Dell Magazine Authors

  Porter chewed her lip, and David thought he saw a moment of doubt cross her face. Then her mouth curled. “Goddamn space cowboy!” She pushed off awkwardly for the engineering compartment door and banged hard against it on her way out.

  * * * *

  David tried to pin the circuit board to the work surface with his wrist. It was no good. The board slipped, and David cursed as he soldered two channels together. The globule of burning plastic had left the back of his hand so blistered and throbbing he could hardly use it. He tossed the board aside into a growing cloud of botched components hovering next to a sheaf of scribbled notes, then looked up at the mission clock on the galley wall. With heartless precision, it announced beam pickup in thirteen hours, forty-one minutes, and eleven seconds.

  Porter had vanished into the cabin they were using as a makeshift infirmary, refusing to speak. She pulled herself through the galley occasionally to retrieve more medical supplies for Beaume—her color fading from furious red toward pallid white with each circuit—but each time she ignored him. Trying to wait me out. She knows my solution will take longer than hers. But for all the lives hanging on it, David would have laughed at their petulance. I may be going to die out here, but they'll not say I ran away.

  The galley door opened, and Porter floundered silently in, awkwardly upright as always. She said nothing, avoided his gaze, and dragged herself toward the medical kit. David, focusing more on her than his work, scraped his hand against the edge of the table.

  Porter turned and frowned at him while he clutched his wrist and cursed. She pulled herself closer and scrutinized his hand.

  “Bloody fool. Why didn't you say something?” She rummaged in the first-aid box for burn ointment and bandages. By the time she finished wrapping the hand, the ointment was starting to relieve some of the throbbing pain.

  “Thanks.” He flexed the hand, frowning at how the bandage limited its usefulness.

  She scowled and turned to leave.

  “That's the first time you've spoken in more than a hundred and fifty thousand kilometers,” David said. “A bit less than an hour ago, we came within two million kilometers of beam pickup. I'm trying to modify the emergency transponder to send out voice messages: the shipboard communication system's fried. If we can't send messages to the Mars station, we won't even be able to navigate a free return trajectory. At least let's do something."

  Her scowl softened a fraction. “What's wrong?"

  David held up his hand. “Damned burn. I feel like I'm trying to sign my name with my boxing gloves on. Is Beaume stable?"

  She nodded reluctantly. “The medical monitor will alert us if his condition changes. What can I do?"

  David gestured to the cloud of discarded circuit boards with its magic carpet of sketches and mathematical speculation. “Grab one of those and hold it steady for me. This should be a ten-minute job, but soldering's a cast-iron bitch in zero gee. Doesn't flow properly.” He worked as he spoke, hoping she'd ask the vital question.

  She did. “What's the drawing?"

  He shrugged. “Idea of mine. Not sure about some of the science, to be honest; I'm more of a nuts and bolts man."

  Porter raised her chin, but held out the circuit board and said nothing.

  “Just turn it over for a second. Thanks. Okay, you can let go now.” David gathered up half a dozen circuit boards and began slotting them into the transponder. Porter eyed the bundle of filmies. Come on. Let's see the ambitious, nosy bitch who made my life hell back in orbit.

  While David fitted pins and wires to the transponder, Porter brushed one of the spoiled circuit boards to one side, then reached out and pulled the bundle toward her. David concentrated on the intricate wiring. Plastic rustled as Porter turned to the second page, and she hummed faintly.

  A few minutes later—six minutes and thirty-one seconds according to the mission clock, or about fifteen thousand kilometers—David risked an open glance at Porter. She still floated next to him, clutching the tabletop with one hand. Her eyes riveted on the sheets, she nearly bumped her shoulders into his chest. David coughed.

  She looked up in surprise, the last of the pages in her hand. Startled by their proximity, she drew back. “This won't work, you know. The incoming ion velocity's too high."

  “I was thinking of using a collider to slow them down,” David said. “Something like a tapering metal funnel, to slow them by collision until they're ready to deionize."

  Porter shook her head. “It'd need to be huge. What you want is something like a giant multichannel plate."

  “A what?"

  “Electron multiplier. Basically an array of slanted tubes bundled together and coated inside with a scintillating compound. Electrons collide with the inside wall and set off a charge cascade. We could use the same thing—without the compound, of course—to slow the incoming ions before they separate."

  David nodded. “I see. The electrons and ions rattle around like peanuts in a jar, then come out the far end slow enough to be used. By using narrower tubes, you make the collisions take place in a smaller space, right?"

  She gave a sudden smile. “Exactly. They'd need to be the right length, though, or the beam would deionize before you got any current out of it."

  “How long?"

  “Depends on the angle of slant. I could work out a formula."

  David grinned. “Brilliant. I can get all the tubing we need out of the plumbing system. So, once we've got the magbeam slowed down to a manageable level, what then?"

  “Well, once you've slowed the beam, you can use an electric field to separate it into electrons and ions, like you suggest, and you should get a current between your two collectors. What were you going to make them out of?"

  “I thought something like the mesh screens out of the ventilation system. The separator I could make out of some metal blinds from a fan outlet—"

  “With the louvers alternately charged positive and negative,” Porter broke in. “I see. You'll need several layers of mesh for the collectors if you want to keep the efficiency up."

  David nodded. “I know. My main concern is heat dissipation. A full-power magbeam would fry anything we could build. If the incoming power's too high, it won't self-cool quickly enough. We need to get the Mars station to run at low power while we're recharging, then turn the power back up past a hundred percent when we're ready to decelerate."

  “Well, contacting Mars is no problem if your transponder works."

  David chewed his lip. “We'll only be able to send, not receive. Our long-distance receiver is slag, and the ones in the spacesuits aren't compatible. We won't know whether Mars received our message."

  “How long do you think the converter would need to recharge the batteries enough to decelerate?"

  “I was hoping you could help me with the numbers. I did a couple of estimates, but you're the math wiz."

  Porter shuffled through the sheets, flailed helplessly in midair for a moment until David dragged her to a seat, then set to scratching figures. Every now and then she would snap her fingers and demand some esoteric figure of merit for the ship or magbeam: mass, battery capacity, charge ratios, power consumptions, ion velocities. Without resorting to computer or calculator she jotted for ten minutes, then triumphantly double-underlined a number.

  “Forty-seven minutes, thirty-one seconds!” she announced. “That's a minimum, of course."

  David closed his eyes and silently blessed the bloody-mindedness of physicists in the face of an intriguing problem. “Okay. If we call it an hour for safety's sake, we'll still have three hours’ deceleration at a bit under a hundred and thirty three percent power. We've got thirteen hours to build this thing and get it into place. I'll need to go EVA to secure it. That's a two-hour job in itself, so let's get to work."

  * * * *

  David took a deep breath and started the recorder attached to his improvised transmitter.

  “Mars station, this is the McAuliffe. At present this is the only communications channe
l available to us. We do not—repeat, do not—possess the ability to receive communications on any frequency. We have suffered a massive power failure and lack sufficient battery reserves to undergo a standard deceleration. Two crew are down. Life support at minimal levels. State of navigation system unknown. We intend to use a space-mounted electrical converter to recharge our batteries from the magbeam prior to executing an emergency deceleration to Mars entry orbit—repeat, Mars entry orbit—for landing and direct rendezvous with the colony for immediate cargo delivery.

  “Execute standard beam pickup, but operate magbeam at one-zero percent power output for six-zero minutes after acquisition. Then increase magbeam power output to one hundred and twenty-nine—that's one-two-nine—percent standard and maintain target lock for one hundred and eighty minutes. We'll do the rest. Wish us luck, Mars station."

  He set the recording to repeat and dragged himself from the cockpit.

  The build had taken far longer than David anticipated, but finally the converter was complete. It didn't look like much for ten hours’ work. About the size of an armchair, the bulk of it was comprised of the big metal blinds from two ventilation ducts. Each of the pivoting metal leaves was attached to the terminals of a tiny power supply cannibalized from a spacesuit. To either side, two metal cylinders jutted. Inside them, behind David's hasty welding, lay the two ion collectors, built of dozens of layers of fine metal mesh. Great coils of insulated power cable protruded from each collector, to carry the electricity they hoped it would generate. He'd spent three hours making the ion collider, welding four hundred lengths of metal tubing to the front of the assembly in an array like a narrow slice cut from a bundle of drinking straws. Heat sinks and cooling fins bristled here and there, welded on wherever space permitted.

  David stood back, trembling from pain and fatigue. He couldn't count the number of times he'd jarred his burned hand in the past hours, turning the persistent burning into lances of fire. The ointment did little to stop the pain, and edema puckered the inflamed skin, swelling his hand to half again its normal size. Porter hung next to him, dirty and exhausted but with a curious glow about her, like a child with a new finger-painting to show her parents. Between them they pushed their creation towards the airlock.

  David pulled a stretchy, one-piece spacesuit undergarment from the rack, then stripped down. He glanced up to see Porter averting her eyes, red creeping up to her face. He pulled on the skintight pants and tried to insert his burned and bandaged hand into the sleeve. After barely an inch, he stopped, weeping in agony as the tight material tore at his burnt hand, setting it bleeding.

  “Longrie? Are you all right?"

  He gasped, trying to recover his breath. “Hold the sleeve straight for me. I'll try again."

  She did, but the tight suit still crushed the bandage against the burn. He stopped her, breathing hard. “It's no good. Even if I can get it on, I won't be able to use the thruster controls or tools properly. You'll have to do the EVA instead."

  All color drained from Porter's face.

  * * * *

  Porter clutched the edge of the galley table, her knuckles white. The mission clock ticked away behind her, unnoticed. After four weeks in space, he should have guessed. All the signs were there: she never admired the view from a porthole, always aligned herself with the gravitational axis of the furniture in the ship, always moved between handholds without drifting free.

  David sucked his teeth. “Why the hell did you insist on coming?"

  “What was I supposed to do? Tell my boss, ‘Sorry, I can't go on the inspection tour because I'm afraid of falling. Your Assistant Director of Space and Aeronautics is terrified of space?’ I'd have been the laughing stock of Washington. Besides, my psychologist told me I could be desensitized if I exposed myself to space. Damn crackpot. Let him take a walk off the edge of the Grand Canyon, see how he likes it."

  “You fell from the edge of the Grand Canyon?"

  She nodded, empty-eyed. “I was nine. My father took us on vacation there. My brothers wanted to use the binoculars and stargaze. We sneaked out of the tourist area after dark and walked along the edge for a while. We were looking up, pointing out the constellations. I stepped over the rim.

  “I hit a ledge about twenty-five feet down, broke my arm, and fractured two vertebrae. I lost the use of my legs and only managed to stay on by clutching some weed growing out of the rock face. The rescue squad took two hours to reach me. All I could see were the stars above me and the darkness below, waiting to swallow me whole.” She shivered. “Now you see why I can't go out in a spacesuit?"

  David spoke quietly. “Even if we turn off life support this minute, the solar panels won't be able to gather enough power for a free return trajectory. If we don't get the converter into place, we die. It's that simple."

  Porter turned haunted eyes on him. “I'm sorry."

  Three hours and twenty-one minutes until beam pickup, the mission clock warned. David cast about helplessly. Take the puncher's chance.

  “Your therapist thought you could get over this by being exposed to what you fear most, did he? Let's try it. We'll start slow, maybe just looking out a porthole. I'll be there to talk you through every moment of it, from start to finish."

  Porter gaped at him. “You're crazy!"

  He barked a short laugh. “Do you have a better idea?"

  * * * *

  David locked Porter's helmet into place. She stared out through the plastic shield, her dark eyes wide with frightened anticipation. He touched a control and was momentarily blinded when the four spotlights mounted around the helmet blazed to life. He gave her a thumbs-up and squeezed out through the airlock's inner door, then swung it home and spun the locking handle. Over the past half hour he'd coaxed her into the clumsy carbon-fiber suit, pushed her to gaze out a porthole while floating free, and now had her ready to open the outer airlock—he hoped. She'd cursed him a blue streak throughout.

  He pulled the communications cap from another spacesuit over his head. “Porter, give me a radio check."

  “I can hear you."

  “Great. I'm going to pump the air out. You don't need to do anything.” He pressed the Atmosphere Purge control and heard the whirr of the extraction pumps. She didn't know he was running internal life support at a dangerously low level just to hoard enough power to run them. He hoped a handheld atmospheric sensor would warn him if the air became too stale to breathe.

  “Okay, Porter, we're ready to go EVA now. Do you remember what I told you?” He wished he could see through her visor-mounted camera, but with the ship's systems down, crackly suit-to-suit radios provided their only link. All he could do was wait by the cargo bay airlock and talk her through the operation.

  Her voice wavered. “Yes. I'm pulling the external release handle now."

  The residual atmosphere in the airlock whistled away out of the hatch. Porter's breathing accelerated as she looked out into the vacuum of space.

  “You're doing great,” David assured her. “Clip the converter to your belt.” He looked through the airlock porthole and saw her latch the bulky instrument onto her spacesuit's retaining harness, next to the connection for her safety line. “Okay. Are you ready to go outside?"

  Porter drew what sounded like a steadying breath. “Why the hell did I let you talk me into this?"

  “Because I'm your Prince Charming. Use the grab handles along the walls to pull yourself towards the hatch. Take it slowly and don't forget you need to stop the converter as well as yourself when you get there."

  “All right, I'm at the hatch. I can see outside.” After a pause, she went on, quavering. “My God, it's full of stars."

  David grinned. “Sure it is, Commander Bowman. To the right of the hatch is your first handhold. Grab it with your right hand, then bring your left hand across your body and reach for the next handhold beyond."

  He glanced down at his watch. In just under two hours and forty-five minutes, the magbeam would reach out to them. If the converte
r wasn't there to meet it, he and Porter would die more alone than two humans had ever been. He looked up. Porter hadn't moved. The converter drifted to the end of its short tether, tugged at her frozen figure, and began its slow return trip to her side.

  “Porter, reach for the handhold."

  Her raspy breathing filled his earpiece.

  “Take the handhold in your right hand and swing across to the next one with your left. Victoria! Do you hear me?"

  An alarm buzzed, barely audible over her panicky breathing. If it were a warning from her suit, he would have heard it more clearly. Abruptly, it stopped. Frowning, he glanced around the cargo bay.

  A squeal came through the earpiece. “Ow! Damn contraption! Who the hell built this heap of junk?"

  David peered into the now empty airlock. “What happened?"

  “Your little fixit toy nearly sliced my suit open with its damn pointy corners. How the hell am I supposed to drag this thing all the way out to the magbeam ring?” A long string of profanity followed.

  “Try shortening the tether.” He could hear her ragged breathing and continuing mutters. “How far have you gotten?"

  “Not far enough. This is impossible. I think I'm going to be sick."

  Not with the meds I pumped into you, you're not. “Just take slow, deep breaths. Let yourself hang in space for a minute. Focus on relaxing. You'll make faster progress if you're relaxed."

  The faint buzz of the alarm reached him again. He pulled off the communications cap, using both ears to pinpoint the sound. To the left, he decided, somewhere up near the engineering section. He drifted to the hatch. As he reached it, the buzzing stopped. Placing the cap back on his head, he heard Porter setting off a new string of curses.

  “Calm down, Victoria, and tell me what's wrong."

  “The damn tether is caught on something! I'm still five meters from the magnet harness, and I can't go any farther."

  David returned to the airlock, and inspected the windlass through the porthole. Plenty of line remained on the spool, but the line trailing out the door stood taut. “Victoria, can you see the full length of your line?"