‘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 frost 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
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
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.
The display also showed an ominous message next to the plotted course:
INSUFFICIENT FUEL FOR FLIGHT PLAN
The last segment of the curve was red, showing when they would run out of fuel. Clare tried not to look at it; they would not know just how far they were away from meeting up with the tug, until they had a more accurate reading on the fuel tank contents.
Instead, she focused on entering in more details of the planned climb, and calculating the launch windows, which happened once every ninety-six minutes.
She forced herself not to get her hopes up, but no matter how hard she tried to detach herself from the situation, her mind kept returning to the hope that this might be their escape from the mine, and from Mercury.
It seemed too much to hope, and she pushed the thought down again, because she had something else, something more precious to her personally, if they ever did escape and make it back to Earth.
The memory module didn’t just contain a copy of the detailed mission plan, it also held a data recording of the last thirty minutes of the spaceplane’s flight – which would be very interesting to a crash investigation team, if they ever got back to Earth.
If there had been any sabotage of the spaceplane’s systems, it would show up, and exonerate her and Wilson. The recorder would have captured everything they had done, every control that they had touched, every word that the flight crew or the passengers had said.
As she thought of the passengers, her earlier unease over Matt came back to trouble her. She stared at the cockpit console as her doubts resurfaced from the dark waters where they had been brooding.
He went straight for the mine entrance, and the hangar.
Did Matt know that the mine would be full of air?
He went straight to the robot.
Did he know that Bob Five would be there, waiting to help them?
She thought back to the many conversations they’d had on board the tug, about what they’d find in the crater. Then there was Matt’s antipathy towards Elliott, and his reluctance to accept any suggestion that the mine personnel hadn’t followed safety procedures. If he was concealing what he knew, he was very good at it.
And what of her own feelings towards Matt? Was her judgement clouded by her attraction towards him, and had she missed the clues that had been staring her in the face all along?
The silent cabin had no answers to her questions, but her natural instincts urged caution. She resolved to say nothing, but to be very careful about accepting Matt’s advice without questioning his motives.
With a sudden shock, she realised where her thoughts were leading her.
In the silo control room, Wilson sat back in his seat, watching the rising temperatures inside the shuttle’s fuel tanks. The situation was looking healthier already, and he just had to wait. Clare was busy doing something inside the shuttle, programming the MMS most likely.
Wilson got up and walked round the bloodstained control room, and shivered. He found himself imagining what had happened in here – the knock at the door, and then the sudden shock as they burst in.
Then the killing had begun.
Wilson’s eyes flickered across the sprays of blood droplets that zigzagged across the walls, and the screams started inside his head.
He stood up suddenly. He had to get out of here, if only for a few minutes. He called Clare on the intercom, and told her he was going to look for a bathroom.
He stepped out of the crawling horrors of the control room, and took a few deep breaths as he leaned against the wall of the corridor outside. His mind cleared a little.
He pushed himself off the wall, and walked back down the corridor, past the T-junction and along the other arm of the corridor, peering into the other rooms, taking his time.
He came to the unlocked door of another control room, and pushed it open cautiously. The silo beyond the glass window was empty, and its roof lay open to the sky. Dust and broken rock had been blown in from the refinery explosion, and lay piled at the bottom of the silo.
Wilson pressed some of the controls on the console, but the silo appeared to be dead. He left the room and
