Mark Anson - Below Mercury

‘There it is.’ He pointed up to where the silver bowl of a parabolic dish antenna stood out on the skyline against the black sky.

Elliott looked up at the dish. It seemed to be on the left-hand side of the pass, high above them. The path became steeper still, and started to wind, first to one side then the other, as it climbed the final slopes of the pass. The bundle of cables, that had followed them all the way here, left the path now and took its own route up the sides of the pass, heading straight for the antenna.

After several reversals of direction, the path turned left and came out into sunlight again. Abrams and Elliott looked up and realised that their climb was over.

At the top of a gentle slope, the main antenna and the solar power array stood on a high ridge that fell away on all sides. To their right, southeast, the ridge plunged down into darkness. On that side, the spur of the mountains fell away down to the surface of the ice field, 3,750 metres below. Beyond the gulf, the Sun blazed above the southern horizon, across the continuation of the crater walls.

On the ridge itself, in a clearing cut into the rock, the large dish of the main antenna pointed towards the horizon on its steerable mounting, with a cluster of smaller antennas and other radio equipment nearby. A short way further on, a huge solar power array stood on a concrete pillar, its glittering array of solar cells jammed at a useless angle to the Sun.

‘Jesus, at last,’ Abrams muttered, ‘that’s not a climb I’d like to do in a hurry.’

They walked up the final slope until they stood in the shadow of the main antenna mount. Fifteen metres in diameter, the lightweight structure of the parabolic dish loomed above them. Another parabolic dish, half the size of the one above them, stood about fifty metres away in its parked position, pointing directly upwards. An array of smaller antennas on fixed mounts littered the area, with a mass of feeder cables running between them.

‘Looks like we won’t have to move the main antenna round very far,’ Elliott said. ‘If I’m not mistaken, Earth is over there.’ He pointed to their left, to the west.

Abrams scanned the horizon. ‘Is that it?’ He indicated a brilliant star low down to their left, which stood out even against the glare of the hills.

‘Ah – no, that’s Venus,’ Elliott said. ‘Keep going to the left, about the same altitude above the horizon. It’ll be a bit less bright than Venus.’

‘Got it.’ Abrams pointed at the bright star of their home world, with the small speck of the Moon close by, rising above a shoulder of the hills. It seemed impossibly far away, and he felt a sudden rush of emotion, a desire to be home, so strong that tears welled in his eyes. He blinked, and looked away, back toward the antenna structure.

Elliott seemed to be affected as well, because he remained standing, staring at the horizon, while Abrams directed the robot to unload the rucksacks and air cylinders.

Elliott came over at last, and helped Abrams unpack the radio equipment and move it over to the large equipment cabinet that housed the high-frequency transmitter. Neither of them said anything; they were busy with their own thoughts.

Using a T-shaped key from his tool pocket, Elliott opened up the cabinet, and traced the feed cable from where it entered the enclosure. Eventually, he spoke.

‘Okay, I think I know what to do here. Can you give me the baseband feed patch cable, the one with the right-angled connector on?’

Abrams bent down and unravelled one of the cables that they had made that morning, and handed it to Elliott, who was busy disconnecting cables inside the cabinet.

‘Thanks.’ Elliott hooked up the cable from the radio, and rerouted more connections inside the cabinet.

Abrams passed him more cables and connectors as he worked. It was hot in the sunlight, and Elliott moved himself round a little to spread the heat load on his suit. He took his time, double-checking the connections, until he was satisfied he had completed the patch correctly.

‘Okay – I’m ready to give it a try now. Can you get that note we made of the coordinates, and turn the antenna mount to face Earth? The control box is over there, where the power cables enter.’

‘Sure.’ Abrams retrieved a small plastic slate from one of his suit pockets and went over to the mount controls. The antenna was normally pointed remotely, by a computer in the control centre, but had evidently been stuck in one position since the accident. He opened the cover to the control panel. A small keypad and control panel lay inside, and a tiny monitor screen that showed a telescopic view from the antenna mount.

Abrams switched the antenna mount to manual control, and punched in the altitude and azimuth figures written on the slate. He pressed the ALIGN button.

For several moments nothing happened; the antenna mount remained stuck in place. Then, with a jerk, the mount freed, and began moving round slowly to its new setting. The shadows around the antenna changed shape as the huge bowl panned across the landscape, turning to point at the bright star of the Earth. Elliott looked up as the shadow of the dish fell over him.

‘That’s great. Right, we’re all hooked up here. I’m going to scan across the Deep Space Control channels, and see if we can hear any transmissions.’

‘Hey, it’s not pointing directly at the Earth,’ Abrams said, looking at the telescopic view. The tiny disc of the Earth was off to one side of the crosshairs.

‘Oh, okay, my numbers are probably a bit out. Can you manually move the antenna to point at the target, and move it around very slightly, until we get a signal?’

‘Yeah, I think so,’ Abrams responded. ‘Okay, I’m moving it now.’

Elliott switched the radio on, and set it up to scan across the frequency range.

‘Right. Let’s hope this works. I’ve set the gain as high as it goes, and patched it into our suit radio channel. Okay, keep as quiet as you can, and move the antenna round, very slowly. If you hear a signal, stop. Okay?’

‘Okay. I’m centred on the target. Moving it around now.’

Elliott closed his eyes and listened to the swish and hiss of the radio. The sound changed in quality as the antenna moved imperceptibly against the sky, becoming thin and faint, and then close and loud again. A high-pitched trilling sound broke out, and Abrams halted the antenna. Elliott listened to the sound, and tried switching the radio coding scheme. The sound changed, but nothing useful could be heard.

‘Keep moving it around, very slowly,’ Elliott said.

The sound broke up and faded as the antenna moved again. Elliott felt that they were close now, and he concentrated, trying to catch any change in the background noise coming from the radio. He thought he heard something, and he strained to hear.

‘—OFF AND ON AGAIN TWICE, OR MAKE CONTACT—’

Both men recoiled in unison from the voice that blasted out in their headsets. Elliott turned the gain down hurriedly. Too far – the voice faded. He got it back, and the recorded voice carried on: ‘—Deep Space Control calling. We have lost contact with you. We have seen an x-band beacon signal on the Erebus Mine frequency. Please respond by switching the beacon signal off and on again twice, or make contact on any deep space channel. Repeat. Mercury Two Zero Seven, this is Deep Space Control calling—’

‘They know we’re here!’ Abrams yelled, his voice jubilant. ‘They’re trying to reach us!’ He came across to Elliott, and thumped him on the shoulder. ‘Fantastic work, Martin!’

Behind his darkened visor, Elliott was grinning.

‘I’m going to try to get the message out. Let me set the frequency, and we’ll see if they can hear us. Have you got the text?’