Below Mercury

by Anson, Mark

  It was cold in the airway; some natural ventilation current blew a slow, chill air up towards them. Clare shivered, and walked faster.

  Halfway down the length of the passage, they came across an electric locomotive and a train of empty passenger cars that had come off the rails. The locomotive appeared to have been hauling the train of open-topped cars back up the incline when it had suddenly derailed. There were some mining helmets scattered about the passage, and rust-coloured splashes of dried blood on some of the seats, but no bodies. It was becoming a familiar sight.

  They found two mining robots near the derailed train: one had fallen over against a roof support; the other stood motionless, looking down the airway, its eyes dark and unseeing. They poked about among the train, but found nothing of interest, and the robots appeared to be completely dead.

  They set off down the airway again.

  ‘Do you buy this mutiny theory?’ Wilson asked, as they walked.

  Clare thought a long time before replying. She had been busy with her own thoughts as she walked, particularly the consequences of the crash on her career.

  At last she said: ‘I don’t know. It makes sense – there’s clearly been a gun battle, and the mutineers could have removed the bodies. And there’s air here – someone must have closed the doors again and repressurised the mine.’

  She walked on a few paces before continuing. ‘But after that, I’m not so sure. The mutineers must have done it for a reason, some objective. More pay? Going home to Earth early? So where are they, and why didn’t we hear from them after the accident?’

  ‘Maybe they screwed up somehow, and killed themselves.’

  Clare looked dubious.

  ‘Maybe. But they must have known a lot about the mine to have rigged the depressurisation. It doesn’t sound right that they could make a simple mistake later.’

  ‘Do you think Matt’s hiding something?’ Wilson asked suddenly.

  Clare stopped.

  ‘Hiding something? What do you mean?’

  ‘Well, don’t you think it’s kind of strange he went straight to the robot, and got it to close the doors. Almost like he knew there was going to be air in the mine.’

  ‘But he …’ Clare was about to say that Matt couldn’t possibly have known, then she stopped.

  Matt had led them towards the mine entrance as the first place to go after the crash. What had made him power up the robot? It had been an odd thing to do.

  She looked at Wilson.

  ‘I don’t think anyone on this expedition expected to find air in the mine. It was as big a surprise to Matt as to any of us.’ She said the words firmly, but Wilson’s words had ignited a spark of doubt, where there had been none before.

  Wilson nodded, but he didn’t meet her eyes.

  They started walking again.

  ‘Have you spoken about this with anyone else?’ Clare asked.

  ‘I talked it over with Elliott. Why?’

  ‘And – what did he say?’

  ‘He said the same thought had occurred to him. I don’t think he trusts Matt.’

  ‘Look. If we start suspecting each other, it’ll eat away at all of us. Just – let this one drop, okay? I’ll talk to Elliott when we get back.’

  ‘Sure.’

  Clare got the feeling that Wilson wasn’t convinced. They walked on in silence for a while, and despite herself, Clare found her thoughts wandering back to the crash, and the discovery of air in the mine. Had Matt been expecting air there? Could Wilson be right to suspect Matt of knowing something? There was no evidence. And yet …

  The worm of doubt turned in her mind. For the moment, she had no answers, but her face remained thoughtful as she walked.

  The red emergency lights came and went, and the featureless walls of the passage went by. Up ahead in the distance, they started to make out some large object in the airway; it was irregular, and nearly filled the passage. As they drew closer, they saw that it was a roof fall; a large pile of broken rock had come away from the roof and one of the walls, partly blocking their way.

  Clare approached cautiously. Her instincts told her to keep clear of the gaping hollow of rock above their heads, and she skirted the pile of fallen rock, keeping close to the undamaged wall. Wilson followed.

  A thin line of dust trickled down onto the rock pile as they turned back to look at it.

  ‘I don’t like the look of that,’ Wilson muttered. ‘Looks like it might all fall in at any moment.’

  ‘Yeah,’ Clare said slowly, wondering what would happen if they became trapped on this side of the roof fall. She cast a last glance up at the roof, before turning back to their descent.

  A short way after the roof fall, they came to a fork in the passage. The airway continued straight ahead, on its downward slope to the air blenders beneath the refinery, and a new, narrower passage opened on the right, continuing on the level, and ending in a set of open pressure doors. There had been a sign at the junction, but it had been torn off, and only one edge remained.

  Clare consulted a hand-drawn map that Matt had sketched for them.

  ‘Well, we’re in the right place. The silos are down here.’ She led the way up the right hand fork and through the red-painted frame of the pressure doors.

  On the other side, the passage continued, but changed in character as they went along, becoming more like a corridor, with walls that were smoother than the roughly-machined mine passages. Doorways opened on either side as they drew nearer to the silos. It began to look more like the accommodation levels; there were rooms for crew briefings, changing rooms with spacesuit lockers, and power distribution rooms. An empty water cooler lay on its side, outside an open door to a room stacked full of equipment boxes.

  Clare glanced back at her map. ‘We’re looking for the control room for Silo Two.’

  They passed more doors, and then the corridor ended in a T-junction. Clare directed them down the right-hand path.

  ‘I think this may be it,’ Wilson announced. He was looking at a security door, standing half-open in the corridor ahead. It was splattered with dried blood.

  They moved forward with a deep sense of foreboding.

  The room inside yawned at them, revealing its ghastly secrets as their flashlight beams moved over the red-lit scene. Blood lay in great dried splashes and smear marks over the control consoles, and on the glass window that formed one side of the room. Through the ochre-stained glass, in the darkness of the silo, they could make out the shape of the shuttlecraft that sat inside on its four splayed legs.

  ‘Shit,’ Wilson muttered. Even after the sobering scenes in the accommodation levels, the scene was shocking. There was even blood on the ceiling, little tracks of droplets in criss-crossing patterns.

  ‘Does this look like gunfire to you?’ he said.

  Clare shook her head. It looked as if someone had used a meat cleaver on the occupants.

  ‘This wasn’t a battle, it was murder,’ Wilson said, his voice shaking. ‘Bastards must have tricked them into opening the door, and then come in and killed them.’

  ‘I’d feel a lot safer if we had some weapons,’ Clare said. ‘If they’re still here, we’re in serious danger.’ She glanced at her watch, and pulled the comlink from her jacket and keyed Bergman’s ID.

  ‘Shit,’ she said after a moment. ‘No coverage here. We’ll have to go back to the airway to see if we can get a signal.’ She glanced around, weighing up the priorities. ‘Okay, I’ll compose a text in a minute. Let’s assess the situation here first. Can we power up the silo?’

  They retrieved two seats that lay on their sides, dragged them to the consoles, and sat down. Wilson touched one of the screens in front of him, and the console sprang into life.

  ‘Promising,’ he commented. ‘Let’s see if it can tell us what state the shuttle’s in.’

  Wilson found the lighting controls, and after a few attempts, a blaze of white light lit up the silo and control room. Having spent so long in semi-darkness, both of them
screwed up their eyes against the sudden glare.

  Outside the curved glass window of the control room, the silo was a large cylinder, twelve metres in diameter, sunk into the crater floor. The roof of the silo was a pair of retractable metal pressure doors that could seal the silo against the vacuum outside, for spacecraft maintenance. The roof was partly closed, which had helped save the silo from being damaged by the refinery explosion.

  The squat shape of a shuttlecraft crouched on the lowered landing platform at the bottom of the silo. The vehicle was a compact arrangement of four fuel tanks, surmounted by a crew module in the shape of a flattened drum just over five metres in diameter. The whole arrangement stood eight metres high on four shock absorbing landing legs, set wide apart for maximum stability.

  Compared to the spaceplane, the shuttle was ugly and utilitarian; its lower structure was a simple trusswork frame through which the fuel tanks, engines, and associated pipework could be seen. To the two people who looked in at it now, however, it seemed a creature beyond beauty, a lifeboat that could get them home.

  As their eyes grew accustomed to the glare, Clare and Wilson saw that the silo was not perfectly white, as it had first appeared; its walls were grey with soot marks and dust blown in from the crater floor from countless landings and takeoffs. The circular landing platform, which was lowered for crew embarkation, was blackened with the exhaust from the engines.

  An extendable docking corridor, like the jetbridge at an airport, reached out from the side of the silo, and was locked on to the shuttle’s main cabin door. What was even more promising, however, was a refuelling boom, carrying several large-diameter pipes from a recess in the silo’s wall to the fuelling connectors below the crew module.

  ‘Looks like they were in the middle of refuelling when the bastards broke in here,’ Wilson said. ‘I wonder how far they got?’ He tapped at the screen for a few seconds.

  ‘Anything?’

  ‘Hold on.’ Wilson scanned the display. ‘Oh, yes—’ He looked up in triumph. ‘It was partly fuelled. The silo’s kept the propane from freezing, but it’s still very cold; we won’t get an accurate reading until the heaters have warmed the tanks up.’

  ‘How much?’ Clare felt as if she could hardly breathe. Please let there be enough in the tanks to make it to orbit, please let there be enough.

  ‘Just a moment.’ Wilson’s mouth worked in silence as he calculated the weight of the fuel and oxygen. ‘Okay. We’ll need to recheck it when it’s up to temperature, but I think there’s – fourteen tonnes.’

  He looked up at Clare, and he saw the hope die in her eyes.

  ‘It’s not enough, is it?’ he said in a whisper. ‘How much do we need?’

  ‘Minimum fuel load for Mercury orbit is eighteen tonnes – I remember it from when I trained on one of these things.’ She bowed her head in despair, looking down at the control console.

  Wilson stared out at the shuttle. ‘I can’t believe we’re so close,’ he whispered.

  Suddenly, Clare’s head snapped up.

  ‘It’s eighteen tonnes for a full load.’ Her voice was urgent. ‘Pull up the performance tables, quickly.’

  Wilson’s fingers moved over the screen, searching out files.

  ‘Got it. No, there it is.’ He tapped at a file icon, and it expanded to fill the screen. He scrolled down the table of launch weights and minimum fuel loads. ‘What load will we have with just six of us and no cargo?’

  ‘Five hundred kilos, no more.’

  ‘Five hundred, five hundred,’ Wilson searched down the list. ‘Okay, the table says we need fourteen point eight tonnes of fuel, but we can save some more weight by throwing out the spare seats and anything else we don’t need. And the fuel load includes a safety margin for manoeuvres in orbit. If we nail the tug first time, we’ll have enough fuel to make it.’

  ‘Or leave us stranded if we don’t,’ Clare muttered. It was terrifyingly close. The Astronautics Corps rules were quite clear: never, ever, take off without sufficient reserve for contingencies. But this wasn’t a normal situation.

  ‘When can you have a more accurate figure for the fuel?’ she asked.

  ‘Soon as it’s warmed up. An hour or so, I guess; it’s pretty cold out there.’

  ‘Okay. Can you get ground power on, and switch on all the heaters. And check out the helium purge as well; we’ll need to clear all the lines.’ She swung her seat round to face the door, and stood up. ‘I’m going to power it up.’

  The docking corridor was dark and cold after the glare of the silo. Clare walked along the narrow, rectangular tube, uncomfortably aware that outside its thin metal walls, there was nothing but vacuum in the silo.

  Light streamed in from the cockpit windows on her left, and glistened on the thin film of frost that clung to some of the metal surfaces.

  The main cabin door of the shuttle was open. She stepped inside, and shivered in the freezing air. Although the silo was protected from the outside by heavy doors, it was close to the surface, and the cold of space had leaked into the silo over the years. Light streamed in through the frost-covered cockpit windows on her left, and glistened on the thin film of frost that covered every surface.

  She squeezed her way between the rows of passenger seats, making her way forward and left to the two flight crew seats that faced the curved cockpit windows. The interior was like an airliner; there were pockets in the seatbacks filled with leaflets, held in place by elastic netting, and a part-circle of overhead stowage lockers ran round the ceiling of the cabin.

  There were no signs of any struggle here. It looked as if the cabin had been cleaned for the next flight and the shuttle was being refuelled, when disaster struck. She sat down in the commander’s seat, on the left-hand side, and put on a headset that she found lying on the centre console. She selected the intercom for the control room.

  ‘Hey.’

  ‘How is it in there?’ Wilson’s voice came over the headset.

  ‘Fucking cold. Can we get the cabin air packs going?’

  ‘Yeah. You should have ground power now.’

  She flipped the master switch on and watched as the cockpit systems started to come to life. She found the controls for the environmental systems, and switched the air packs on. Moments later, a blast of icy air roared out of the vents near her seat. She gritted her teeth until the heaters kicked in, and the air began to warm up.

  There was a dog-eared flight manual in one of the document pockets on her left, and she pulled it out and looked through the pre-flight checklists. She hadn’t flown a vehicle like this for a long time, except in a simulator, but they were pretty straightforward, and she felt her confidence grow as she worked her way through the checklists.

  She set the batteries on to charge.

  ‘How are we doing with that helium?’ she asked Wilson over the intercom. The frost was beginning to clear from the window, and she could just see Wilson in the control room. She raised her hand, and he waved back.

  ‘Got pressure. You want me to start the purge?’

  ‘Yeah. Keep it going while the fuel lines warm up.’

  A muffled roar broke out in the pipework of the vehicle beneath Clare as dry helium gas surged under pressure through the hoses and pipes of the fuel system and engines. The ‘purge’ was essential, to clear the entire system of any foreign particles and moisture that could cause problems for the engines. Even the tiniest drop of moisture would freeze instantly in the cryogenic propellants, and could damage the turbopumps, or worse still, find its way to the engine injectors and cause an explosion.

  Clare switched to the fuel display. The two tanks of liquid propane were still very cold, as Wilson had said, but she could see the temperatures starting to move upwards. The liquid oxygen tanks were fine – it wouldn’t freeze even at these temperatures – but Wilson had turned on the stirrers, to help get it to a uniform density.

  She realised she wasn’t shivering any more; the air coming from the vents was warming up. Melting fros
t formed beads of moisture over the cockpit console. She wiped them off the displays with her sleeve.

  The roar of helium lessened, and faded to a hiss as Wilson reduced the purge, but kept it going to flush all the moisture from the system.

  ‘Okay,’ Clare muttered to herself, ‘let’s see what’s in the flight computer.’ She brought up the mission management system on her main display, and peered at it intently. The previous settings were still in the computer; the shuttle had been programmed for a suborbital flight, passing over various navigation beacons in and around the crater. Clare stepped through the mission sequence, and realised that it must have been a training flight, not a shuttle up to a waiting tug in orbit.

  Of course, she thought. There were no space tugs in orbit at the time of the accident; the Cleveland had already left. That’s why the fuel load was so small.

  She cleared the flight plan, and entered a new one to take them into orbit. She entered in the average masses of the six of them, and Wilson’s guess at the fuel load. She could remember the basic orbital parameters of the Baltimore, enough to get them close enough to lock onto the tug’s docking beacon, but she had an ace up her sleeve – almost literally.

  Hanging round her neck by a thin cord was the small memory module that she had pulled from the spaceplane’s MMS console before jumping down the escape slide, seconds before the ship exploded. The module held a copy of the spaceplane’s entire mission plan, including precise details of the space tug’s orbit.

  Clare passed the cord over her head, and inserted the memory module into a socket in the shuttle’s mission management system. She browsed through its contents until she found the tug’s orbital data, and uploaded it to the MMS. Now the flight computer could work out the precise trajectory to intercept the tug in the vastness of the Mercurian sky.

  In front of her, the pilot’s navigation display changed, showing a plot of their long climb to rendezvous with the orbiting tug. The thin magenta line of the shuttle’s trajectory climbed straight up to clear the encircling mountains, then arced over into a long curve that eventually intersected the tug’s orbit, 200 kilometres above them.