Read Below Mercury for Free Online

turned against the stars above them. Its vast landscape rolled by, craters and old blowholes coming into sharp relief as they caught oblique rays from the distant Sun, then fading into inky blackness as they rolled into shadow.
    They had spent the last half hour matching speed with the asteroid; now it was time for the final approach and landing.
    ‘Okay, you’re doing well. Now, on the next rotation, as your landmark comes up, get ready to fire the engines at the computed thrust. I’ve set the burn duration and thrust level in the MMS, so all you have to do is get the timing right. Okay?’
    ‘Yep.’ The pilot’s entire concentration was on the controls and the display in front of him, which showed a wire-frame model of the asteroid turning in space above them.
    ‘Here it comes.’ Clare pointed out the distant mountain peak that they had selected as a reference point on the first pass. ‘Now remember, there’s about half a second between hitting the button and getting ignition, so aim a little ahead. I’d suggest that outcrop just ahead of the peak, just coming into the Sun now. Got it?’
    ‘Yes, I see it.’
    Clare glanced down at the checklist display on the cockpit console and selected some switches on the central console. ‘Fuel valves are – set to auto. Pre-ignition checklist is complete down to arming.’
    The pilot’s breathing quickened as his fingers crept to the engine controls. He flicked the master arming button.
    ‘ Ignition sequence armed,’ the ship’s flight computer confirmed. The pilot’s eyes flicked from the asteroid rolling past above, to the navigation display, to the primary flight display, to the engine controls. The distant outcrop he was watching drew slowly closer. As it passed level with the ship, he pressed the firing button.
    A distant whine, and a muffled thump, then a faint vibration came through the ship as the engines ignited and burned, slowing the ship’s forward speed until it matched the asteroid’s rotation. Clare gripped the arms of her seat as the thrust rose to full power.
    The noise of the engines faded, as the short burn came to an end.
    ‘ Burn complete. Engine safed,’ the flight computer announced.
    ‘Quickly now, remember that we’re not in orbit. We have to descend while we’re moving at zero relative speed, but leave it too long and the surface will start to move under us.’
    The pilot armed the thrusters, and turned the landing craft round, then pitched it forward until it was oriented for landing. The asteroid’s surface was below them now, filling their field of view.
    ‘Good. Now take us down.’
    He fired the thrusters again, in one long burst that pushed them towards the landscape below.
    ‘Aim for a landing point now.’
    ‘I’ll go for that flat-bottomed crater just in front of that vee-shaped outcrop there,’ the pilot said. Clare nodded, without comment. There were some slightly better sites, but none so close or so easy to see, and it was important to choose the site early.
    ‘ Five hundred metres,’ the computer reminded them.
    Another burst of thrust, slightly forward this time, and the crater-marked hills and ridges started to drift beneath them.
    ‘They’re moving,’ his voice contained a trace of panic.
    ‘Correct your relative speed. Thrust back a bit.’
    The thrusters fired again.
    ‘ Four hundred metres. Sink rate.’
‘Don’t worry about that, you’re doing fine. Just keep the target steady below you.’
    The crater they were aiming for slowed in its motion, then started to slide backwards, away from them. Quickly, the pilot applied forward thrust in one long burst.
    ‘No, that’s too much,’ Clare cautioned, ‘you’ll need to correct.’
    The pilot hesitated. The landing point had moved again, and was now aligned perfectly.
    ‘Correct now,’ Clare’s voice was firm.
    ‘I don’t—’ he began, but then the crater started to move again, sliding underneath them and disappearing. A succession of rising