Voyage

by Stephen Baxter

  Stone climbed on top of a rock, the heavy pack banging against his back, and peered around. ‘More uplands, carved out of the sedimentary stuff. They look –’

  ‘What?’

  ‘Smooth. Streamlined.’ Like islands, their flanks smoothed out, left stranded by the drying out of a parent river. ‘And I can see what look like bars of gravel, some maybe twenty, thirty feet high. Kind of like sand banks. They seem to have formed behind outcroppings, maybe of loess, or bedrock. Like tails. The rock has grooves scoured in it. Longitudinal. The grooves flow past the islands, and the gravel bars.’

  He came to a bed of loose clay and sand. ‘This is more loess, I think. I see –’

  ‘What?’

  ‘Ripples. Kind of frozen here, in the loess. Like small dunes, I guess. The dunes are stratified. It looks as if a river has dried out here.’ He stalked on over the rock. ‘I got pits in the rock surface. Circular, a few inches deep, width from a foot wide upwards. Scallop pits, I think.’ Gouged out by pebbles, carried by turbulence … ‘The whole place is kind of like a river bottom,’ he said. ‘Yeah. You basically have the topography of a dried-out river bottom – but magnified. Channels and bars and islands. All shaped by flowing water on a massive scale …’

  He looked around with a new excitement, seeing the geology with new eyes, with Natalie York’s eyes: the deep-carved, breached channels, the huge deposits of loess, the carved-out islands. ‘Christ. Is that it, Natalie? Is that what you’ve brought us out here to see? Was all of this region formed by a flood?’

  ‘You’re speculating again, Stone.’

  ‘Oh, come on, York.’

  ‘Okay. You’re right, Phil. At least, that’s the favored hypothesis.’

  Bleeker gave up on the half-assembled CELSS, and came to stand close to Stone. ‘What is?’

  York said, ‘In the Late Pleistocene – maybe twenty thousand years ago – much of Idaho and West Montana was covered by an immense lake. Called Missoula. Thousands of square miles of it. The lake was contained by an ice dam. The dam eventually burst, and released a catastrophic flood that swept over this area. Tens of millions of cubic yards per second, maybe a thousand times as much as the Amazon’s discharge rate –’

  ‘Jesus,’ Stone said.

  ‘Yeah. The existing streamways couldn’t cope with the sudden volume, so they burst; the valleys were widened and deepened, and interconnecting channels were cut – all the way into the bedrock – in hundreds of places. Thousands of square miles were swept clean of the superficial structures, right down to the basalt bedrock, and another thousand square miles were buried in river-bottom debris.

  ‘We’re left with hundreds of cataract ledges, basins and canyons eroded into the bedrock, isolated buttes and uplands, gravel bars thirty or forty yards high.

  ‘This is the scabland, Phil. There are only a handful of areas on Earth which show the effects of large-scale, catastrophic flooding so well.’

  Bleeker pushed back his Snoopy hat and scratched his blond head, ‘It’s fascinating, Natalie. But I don’t see what it has to do with us.’

  ‘Okay. Phil, I’ve given you another pack of photographs. In the left side-pocket of Adam’s pack.’

  Stone dug into Bleeker’s pocket and pulled out a plastic packet of black and white photographs. He leafed through them quickly, showing them to Bleeker.

  Cratered plains: the images were of Mars, clearly enough. But here was a channel cut deeply into what looked like the tough, ancient landscape of the southern hemisphere. Here was a crater complex, overlaid by anastomosed channels. Here was a crater with a teardrop-shaped, streamlined island, like a gravel bar, collected in its wake; and ‘downstream’ of the crater, there were scour marks, running parallel to the island …

  Stone was having trouble making sense of this. ‘Are you saying that Mars has suffered catastrophic flooding – like the scabland here, in Washington State?’

  York hesitated. ‘I believe so. A lot of us have argued that, since the Mariner pictures came in. I’ve been studying the area you’re looking at, in those photos, since 1973. I guess I’m. the leading expert on it, now. And it seems to me the analogy between the terrestrial scabland features and the Martian morphology is too striking to be a coincidence.’

  ‘But not everybody agrees,’ Stone hazarded.

  ‘No,’ she conceded. ‘Some say the Martian “scabland” features are too big to have been formed by water. Schumm, for instance.’

  ‘Who?’ Bleeker asked.

  ‘Schumm says the Martian channels must have been formed by tensional factors in the planet’s surface. Cracks, modified later, maybe, by vulcanism and the action of the wind.’

  ‘Sounds like an asshole to me,’ Stone said, peering at the pictures. ‘I’m with you, Natalie.’

  ‘But if these Martian channels were formed by flooding,’ Bleeker said, ‘where the hell did the water come from? And where did it go?’

  ‘I’ll bet she has a theory about that, too,’ Stone muttered.

  ‘I didn’t copy, EV1.’

  ‘Go ahead, Natalie.’

  ‘Underground aquifers. Contained by tough bedrock below – maybe ten miles deep – and a cap of thick ice in the regolith above. Whatever lifted up Tharsis – a convection process in the mantle, maybe – must have caused the faulting that led to the flooding. The pressure of the water got to exceed the pressure of the rocks. All you’d need would be a breach on the subsurface ice cap for the water to gush to the surface, under high pressure.’

  ‘My God,’ Stone said. ‘Oceans, buried in the Martian rocks. How can we find out if you’re right, Natalie?’

  ‘What we need is for three guys to land there in a MEM, and dig a few deep cores.’

  Stone started to see where all this was leading. He leafed through the photos again. ‘What area are these photos of?’

  ‘That’s one of the most striking outflow channels. It’s Mangala Vallis, Phil. Martian scabland: your landing area.’

  Stone grinned. She’s doing it again. Mangala Vallis. On Which Natalie York, leading light of the site selection committee and would-be Mars voyager, just happens to be the world’s top expert.

  And Adam Bleeker still doesn’t know what anastomosis is. I hope the guy’s watching his back.

  Mission Elapsed Time [Day/Hr:Min:Sec] Plus 349/11:14:03

  Twenty days from orbit insertion, Mars had opened out into a disk. Where the line between light and dark crossed the planet, she could see, with her naked eye, wrinkles and bumps in the surface: craters and canyons catching the light of the sun.

  It was remarkable how much she could recognize. Almost as if she had been here before. There was the huge gouge of the Valles Marineris – a wound visible even from a million miles out – and the polar cap in the north, swelling with water ice in advance of the coming winter, and the great black calderas of the Tharsis volcanoes.

  Mars was clearly a small world, she thought. Some of the features – Tharsis, the Marineris canyons, Syrtis, the great iced pit of Hellas in the south – sprawled around the globe, outsized, dominating the curvature.

  In some ways Mars was as she had expected. It looked a lot like the big photomosaic globes at JPL. But there were surprising differences too. Mars wasn’t red so much as predominantly brown, a surface wrought out of subde shadings of tan and ochre and rust. There was a sharp visible difference between northern and southern hemispheres, with the younger lands to the north of the equatorial line being brighter in color, almost yellow.

  Ares was approaching the planet at an angle to the sunlight, so Mars was gibbous, with a fat slice of the night hemisphere turned toward the spacecraft. And the ochre shading seemed to deepen at the planet’s limb, and at low sun angles. These features gave the little globe a marked roundness. Mars was a little round orange, the only object apart from the sun in all the three-hundred-and-sixty-degree sky visible as other than a point of light.

  In the depths of the mission – suspended between planets, with nothing vi
sible but sun and stars beyond the walls of the craft, and ground down by the stultifying routine of long-duration flight – York had suffered some deep depressions. She’d shrunk into herself, going through her assignments on autopilot, shunning the company of her crewmates. She suspected they’d suffered similarly, but they seemed to have found ways to cope: Gershon with his love of the machinery around them, Stone with his little pet pea plants.

  Already she was dreading the return journey; it loomed in her imagination, a huge black barrier.

  But that was for the future. Right now she was climbing out of the pit, up toward the warm ochre light of Mars.

  She spent as much time as she could just staring at the approaching globe, identifying sites no naked human eye had seen before, as if claiming more and more of Mars for herself.

  Monday, August 6, 1984 MEM Spacecraft 009, Low Earth Orbit

  As they prepared for the ignition, Bleeker had Born in the USA playing on the cabin’s little tape deck. It drowned out the clicks and whirs of the MEM’s equipment.

  Bleeker said, ‘Ascent propulsion system propellant tanks pressurized.’

  ‘Rager,’ Gershon replied.

  ‘Ascent feeds are open, shut-offs are closed.’

  On the ground, Ted Curval was capcom today. ‘Iowa, this is Houston. Less than ten minutes here. Everything looks good. Just a reminder. We want the rendezvous radar mode switch in LGC just as it is on surface fifty-nine … We assume the steerable is in track mode auto.’

  Gershon said, ‘Stop, push-button reset, abort to abort stage reset.’

  Bleeker pushed his buttons. ‘Reset.’

  Curval said, ‘Our guidance recommendation is PGNS, and you’re cleared for ignition.

  ‘Rog. We’re number one on the runway …’

  A hundred miles above the Earth, as Gershon and Bleeker worked through the litany of the pre-burn checklist, MEM and Apollo drifted in formation. The Apollo, containing Command Module Pilot Bob Crippen, was an exquisitely jeweled silver toy, drifting against the luminous carpet of Earth. And the MEM was a great shining cone, at thirty feet tall dwarfing Apollo, surrounded by discarded Mars heatshield panels and rippling with foil.

  Its six squat landing legs were folded out and extended. But MEM 009 was destined to land nowhere.

  Gershon stood harnessed in place beside Bleeker in the cramped little cabin of the MEM’s ascent stage. He felt bulky, awkward in his orange pressure suit. In front of Gershon was a square instrument panel, packed with dials and switches and instruments. There were two sets of hand controllers, one for each man. More circuit breakers coated the walls, and there were uncovered bundles of wiring and plumbing along the floor. The cabin had two small triangular windows, one to either side of the main panel, calibrated with the spidery markings that would help guide a landing on Mars. Blue Earthlight shone through the windows, dappling the cabin’s panels.

  Behind Gershon there were three acceleration couches, two of them folded up. On a landing flight there would be a third crewman in here, the mission specialist, a passenger during the MEM’s single brief flight.

  The cabin’s surfaces were utilitarian, functional, mostly unpainted, with everything riveted together, the bundles of wires lashed together by hand as if in a home workshop.

  The MEM was an experimental ship: the product of hand-crafting, of thousands of man-hours of patient labor, and based on conservative designs, stuff that had worked before. The apparent coarseness of the construction was the feature of space hardware that most surprised people used to sleek mass-produced technology. It was nothing like Star Trek.

  But to Gershon the MEM was real, almost earthy.

  To descend to Mars, in a ship assembled by the hands and muscles of humans: to Gershon, still elated to be in space at all, there was something wonderful about the thought.

  As long as the mother worked, of course.

  ‘Coming up on two minutes,’ Curval called up. ‘Mark, T minus two minutes.’

  ‘Roger,’ Bleeker said. He turned off the tape.

  Glancing at his panel, Gershon could see that the ascent stage was powered up now, no longer drawing any juice from the lower stage’s batteries. It was preparing to become an independent spacecraft for the first time.

  In this test, simulating a launch from the Martian surface, the whole unlikely MEM assemblage was supposed to come apart, releasing the stick-like ascent stage with its ungainly, strap-on propellant tanks.

  Gershon knew this was the moment on the mission that was most feared by the engineers at Columbia and Marshall. There were too many ways for the fucking thing to go wrong. Like, the ascent stage ignition would take place with the engine bell still buried within the guts of the MEM’s descent stage. What if there was a blow-back, an over-pressure of some kind, before the ascent stage got clear? …

  Well, they were soon going to find out.

  Bleeker said, ‘Guidance steering in the PGNS. Deadband minimum, ATT control, mode control auto.’

  ‘Auto,’ Gershon responded.

  ‘One minute,’ the capcom said.

  ‘Got the steering in the abort guidance.’

  Gershon armed the ignition. ‘Okay, master arm on.’

  ‘Rog.’

  ‘You’re go, Iowa,’ said Curval.

  ‘Rager. Clear the runway.’

  Bleeker turned to him. ‘You ready?’

  ‘Sure.’

  ‘That mother may give us a kick.’ Bleeker reminded him of the drill. ‘Okay, Ralph. At five seconds I’m going to hit ABORT STAGE and ENGINE ARM. And you’ll hit PROCEED.’

  ‘Rager.’

  ‘Here we go. Nine. Eight. Seven. Six. Five.’

  Beyond the small window in front of Gershon’s face, the shining blue horizon of Earth drifted by, a complex, clearly three-dimensional sculpture of cloud over sea.

  The computer display in front of Gershon flashed a ‘99,’ a request to proceed. He glanced across at Bleeker.

  Bleeker closed the master firing arm. ‘Engine arm ascent.’

  Gershon pressed the PROCEED button.

  There was a loud bang, a rattle around the floor of the cabin. Pyrotechnic guillotines were blowing away the nuts, bolts, wires and water hoses connecting the upper and lower stages of the MEM.

  A weight descended smoothly on Gershon’s shoulders.

  ‘First stage engine on ascent,’ Bleeker said. ‘Here we go.’ He smiled. ‘Beautiful.’

  After his unexpected, incredible assignment to the prime Mars crew, Gershon had been happy to be bumped onto this D-prime test mission. His first flight into space might not have been the most glamorous in the MEM test program – that would probably be the one remaining E mission, the attempt to bring a reinforced MEM in through the Earth’s atmosphere and land it on the salt flats around Edwards Air Force Base. That had been given to an experienced crew led by John Young. But the D-prime, an eleven-day Earth-orbit shakedown flight, was arguably the more important test. In an untried spacecraft, the crew would rehearse every phase of the Mars landing mission save only the atmospheric entry and final powered descent; and, as well, they would rehearse many contingency procedures which might save future missions.

  Already, in the MEM, Gershon and Bleeker had ventured as much as a hundred miles from Apollo. In a craft which nobody had tried to rendezvous with before. Which didn’t have a heatshield strong enough to get them back to the ground. And on top of that, the whole flight was in low Earth orbit, where communications and navigation challenges were even tougher than on, say, a flight to the Moon.

  If they got through this flight the MEM would be man-rated, with only the Mars heatshield remaining to be test-flown. It was a connoisseur’s spaceflight, a flight for true test pilots.

  And besides, Gershon had been happy to bury himself in the mission, to get away from the attention his assignment to the Mars crew had brought him. The first black man in space: the first brother on Mars. He was learning to deal with it, but it was relentless, distracting. And nothing to
do with him.

  As far as he was concerned he was Ralph Gershon, complete and entire, and not a symbol of anyone else’s agenda.

  However, the mission had been snake-bit: nothing but problems from the beginning.

  It started even before the launch, in fact. Gershon had seen JK Lee’s people at Columbia tearing their hair out as they tried to coax Spacecraft 009 through its final prelaunch checkout in the Vehicle Assembly Building at the Cape. There had been times when Gershon had become convinced that it wouldn’t come together at all.

  Then, once they had reached orbit and opened up the docking tunnel between Apollo and MEM, Gershon found himself floating in a snowstorm of white fiberglass. It had blown out of an insulation blanket in the tunnel wall. Gershon and Bleeker had spent their first couple of hours in the MEM just vacuuming all that crap out of the air, and they had finished up with white stuff clinging to their hair, their eyelashes, their mouths, until they’d looked like nothing so much as a pair of plucked chickens.

  After that Bleeker and Gershon had crawled all over the MEM, putting the subsystems through comprehensive tests. And every damn one of those tests had given them problems, which had needed diagnosis and repeated testing.

  There had been that odd, sour smell coming from the environment control system in the surface shelter, for instance, which they had finally traced to a piece of scuffed insulation slowly scorching behind a panel. The electrical power system had shown some severe faults, with whole panels of instruments just cutting out. Meanwhile the inertial guidance system was a pig, wallowing inside its big metal sphere, constantly losing its lock. And the MEM’s big antennae complex had gotten stuck, and for a while it couldn’t talk to the Apollo or the ground …

  Relationships between the crew and the ground had gotten strained in all of this. As they wrestled with the craft, Bleeker, as commander, had become concerned that Houston was reluctant to make any compromises in the scientific and PR elements of the flight plan – which, as far as Bleeker and Gershon were concerned, came a long way down the list in comparison to the engineering objectives of the mission. So Bleeker, showing an unexpected assertiveness, got into battles with the flight controllers. He canceled TV broadcasts, and he blue-penciled whole sections out of the flight plan.