Mark Anson - Below Mercury

‘Set descent to take us through the peaks at three thousand, and watch your clearance,’ Clare ordered, her voice tense. Wilson reached out to the autopilot, and the landing jets fell to a hushed whisper.

The ship seemed to hang above the crater, as if reluctant to fall into the terrible gulf, but Mercury’s gravity would not release it, and pulled it relentlessly inward. Like a winged demon returning to the underworld, the spaceplane slid into the abyss below them, deeper and deeper, until it felt like they were falling into the pits of Hell itself. There was no way of telling how deep it went; it was like falling into a bottomless void.

The voices on the deep space control channel in Wilson’s headset became garbled and broken, came back again briefly, then disappeared into a meaningless hiss of random noise as the ship fell out of radio contact.

The distant peaks of the crater rim retreated towards the edges of the world. The Sun followed the mountains down the sky and set behind them, shrinking to a bright arc on the edge of the world. There was a sudden flicker as the last rays stole between the mountain peaks, then it was gone, and darkness closed around them.

The cockpit windows adjusted to the loss of light, losing their polarisation and protective tint, and stars came out in the great bowl of the sky above the crater. Above the vanished Sun, the solar corona flared, the hidden nimbus of light that was invisible from Earth except during an eclipse. Out here, close to the Sun and with no atmosphere to refract the Sun’s light, the corona was enormous; a huge arch of luminous gas reaching high above the crater rim.

Their descent continued, and they watched as the corona sank behind the mountains. It faded to wisps and filaments of glowing gas, flickering and blowing above the crater rim, a reminder of the deadly radiation that sleeted over the landscape. As they fell deeper still, the last faint remnants sank from sight, leaving the sky to the stars.

Below them, and all around, the utter blackness of the crater seemed to suck them in, a deeper night than the starry sky above. The crater rim marched on the horizon, black against the stars.

Ahead of them now, the central mountains rose into the sky, growing with each minute as the spaceplane slid towards the heart of the crater. The peaks climbed out of the darkness of the crater and into the high sunlight, great spires of rock formed from the rebounding of the ancient impact flow, their tumbled lower slopes hidden in the darkness.

Their course took them through a valley between two of the tallest peaks. As they drew closer, the sunlit heights soared up into the sky on either side until they were lost to view, high above the spaceplane. On the night vision displays, they could see the invisible ramparts and mountain buttresses that slid silently past alongside in the darkness. Great screes and boulder slopes fell down toward the hidden valley floor, the sheer rock faces softened from countless minor impacts.

The sides of the valley rose and drew together, until it seemed that they would never make it through, but at the last moment, a gap opened between two great mountain buttresses, sharp-edged in the sunlight, standing like sentinels at the gates of night.

The ship slipped through the gap, and sailed out again over the darkness of the crater plain, turning towards an outthrust spur of the far crater wall, just visible on the far horizon.

‘Passing waypoint, coming round to one eight zero. Sixty kilometres to landing site, descending through three thousand metres, slightly high on the approach path,’ Wilson said, his eyes flicking over the instruments.

‘Reduce speed to one four zero. Maintain descent to two thousand metres for final approach, call out range and altitude.’ Clare’s hand moved out to touch the sidestick, her eyes watching the landing approach display.

Six slow minutes went by, while the invisible crater floor rolled past beneath them, and the far crater wall loomed closer, its dark ramparts rising to block out the stars.

‘Test landing thrust.’ Clare said.

Wilson pushed the thrust levers forward, and the crew felt the ship push upwards, as the landing thrusters were tested to their roaring maximum, sufficient to make a lift-off for their return journey.

‘Full thrust, engine readings normal,’ Wilson reported. ‘Reducing to descent thrust.’

The roar of the jets faded back to a hiss as the spaceplane continued its slow fall, sliding down into the depths of the crater. Outside the windows, the towering mountains had risen to block out the stars, and the ship floated in utter darkness.

‘Ten kilometres to landing site, altitude two thousand metres, approach checklist complete,’ Wilson announced, pressing a switch on the overhead panel. ‘Turning onto one three zero for final approach.’

The spaceplane dipped a wing and banked to the left, until it was heading straight for the unseen base of the mountain spur.

‘Any nav signals?’ Clare asked.

Wilson shook his head.

‘Negative. Not even a beacon. That’s one dead base down there.’

‘Reduce speed to five zero, increase rate of descent to ten metres per second,’ Clare said quietly. The spaceplane’s nose lifted as Wilson adjusted the autopilot, angling the landing jets to brake their forward speed and take them down on a steep descent towards the crater floor.

‘Eight kilometres range, altitude sixteen hundred metres,’ Wilson called.

Clare thumbed the intercom to the passengers. ‘Everyone ready? Let’s have those faceplates down and locked now.’

Behind her in the cockpit, there were thunking and clicking sounds as the crew closed their helmet faceplates, and the sharp hiss of suit air supplies taking over.

‘Five kilometres range, altitude one thousand metres.’

Only the radar display showed them what was happening outside, its flickering green eye showing them the fuzzy outline of the mine complex, far below and ahead of them in the darkness.

‘Four kilometres range, altitude eight hundred fifty metres.’

Clare reached for the landing gear control handle.

There was a series of thumps below them as the landing gear doors opened and the wheels swung downwards and locked in position.

Wilson kept focused on the descent, watching their forward speed and sink rate towards the landing pad. Clare turned her attention back to the approach display, trying to pick out individual features from the radar returns.

‘One kilometre range, altitude two hundred fifty metres.’

Clare could see the landing pad in the distance, a sharp-edged rectangle on the floor of the crater, and some of the taxiways, but the rest of the image was confused and broken.

‘Reduce speed to ten, level off at one fifty metres.’

The hiss of the landing jets increased briefly to a roar as Wilson arrested their descent and slowed their forward motion. Clare watched the displays intently as the ship moved slowly forward towards the landing pad.

‘Three hundred metres to pad, holding at one hundred fifty metres.’

‘Keep it coming, real slow now.’

The spaceplane slid closer to the image of the landing pad on the approach displays.

‘One hundred metres.’

‘Okay, that’s close enough, bring us to a hover.’

Wilson slowed the ship until it halted, hanging motionless, suspended in the darkness on its landing jets.

‘Hovering.’

‘Let’s have the landing lights.’

Below the spaceplane, six powerful lights pierced the blackness, and on the night vision displays in the cockpit, the crater floor could be made out at last.

It took a moment or two for the scene to sink in.

‘Oh my God,’ Matt let out, hardly able to believe what he saw.