Dior Aubert knew she wasn't the only one of the Smaug's crew to have noticed the slight and growing deviation in their course as they prepared for atmospheric braking, but it was Arnon Sable who spoke up first, in his sunny Kiwi drawl: "Projected landing point showing thirteen k west, twenty-one point five south." This was his Mission voice, like an iced drink on a summer's day, almost as relaxed as if reading the cricket scores out of a newspaper. "Lieutenant, please give us a suitable manual RCS correction." She could hear the humour in his voice.
"Yessir," came Dior's crisp response. She hardly had to think. She was in precise control. This was her element.
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| Image credit: NASA |
"Isn't it wonderful, this fully-automated system?" Sable said, as if to himself.
She couldn't answer. She couldn't do funny when she was in her zone.
She had once asked him, after a particularly fraught survival exercise in the Arctic wilderness that had involved two separate polar bears, both of them desperately hungry, how he kept so calm. He had grinned at her, with his crooked front teeth through his grey-brown sprouting goatee and said, "Somewhere on the inside, I'm panicking as good as the next man, but I just got into the habit of refusing to listen to that. Maybe I just don't care, in the very end, whether stuff goes wrong. I dunno." Then after a pause, he'd added, self-consciously, "And I must say, knowing that my life's part of greater designs does change everything. Faith in the Great Mission Controller in the sky." Then that grin again. She remembered feeling unsettled by his answer, but now it didn't matter. She trusted him to keep not-listening, or not-caring, or whatever it took. And she had since identified a similar ability in herself to push back the panic, sometimes. She found Sable's low-anxiety outlook on life to be infectious.
Her gloved finger tapped the touchscreen to access RCS control and she carefully applied several tiny amounts of thrust. She could barely feel the effect of the throttled-back Draco thrusters, but the course change was enough to nudge the projected landing point back towards the centre spot. Then another equal and opposite burst to cancel the rotational movement. Not perfect, she realised, but close enough. From this far out, the projections weren't so accurate anyway. She verified that the Dragon's nose was still within a fraction of a degree of their heading and desired pitch, as they aimed at the edge of the Red Planet's disc. She knew how the control algorithms had been finessed to give a cautious balance between conserving Draco rocket fuel and not letting their trajectory stray beyond bounds. She dimly remembered the long debates about that, long before launch, and how she and Arnon had agreed to concede to the louder voices. Now the two of them could have the last word. She found that she was smirking to herself.
On the Red Dragon spacecraft's screens, Mars appeared as a broad horizon of mist-rimmed ochre, incredibly textured and speckled with features. Dior scanned the primary ahead-screen, drinking in the first-hand view. She felt her breathing accelerating, despite her efforts to keep calm. Alongside her detachment she needed - as the one crew member who was meant to be able to land the Dragon manually in the event of some freak computer failure - a childlike glee and awe was chattering away in her head: Look, is that Elysium Mons
She lay on her couch between Julia on her left and Leo on her right. Julia, highly strung but determined not to slip, returned a nervous glance. Leo was preoccupied with navigational readings. He scowled at his twin screens. Arnon sat behind and above her left shoulder, flanked by July and Hugo. In place of the seventh couch sat the custom cargo crate, whose contents had been contested so hotly, but now so long ago, it seemed, that its bulk only gave her a dull and fading ache. They'd been stuck in the Red Dragon III for more than twelve hours now, and compared to the Bigelow B450, in which they had travelled from low Earth orbit, it was like the confinement of one of those long road trips across the USA, without the varied views. Her legs had cramped up with the inactivity. No matter that the enlarged, crewed version of the Red Dragon Mars lander had three cubic metres of extra cabin volume; it was hard to tell the difference between the inside of this and the original version used for crewed flights to and from the ISS. But from the outside there was no confusing one with the other.
"We're four minutes to Entry Interface," said Sable. "Let's hear our altitude and range to target, please, at intervals of… let's say twenty seconds. Velocity's still steady at six-point-five klicks."
Leo Fortuyn knew that was his role and read off the current figure: "Three hundred and eighteen k, and one-eight-two-four." To Dior he sounded gruff, almost smoldering or resentful, but she knew how the stress of action could play with people's autonomic nervous system and voice tone. She had heard him square off with Sable too many times, that was all, she told herself. They had simulated every conceivable situation so often, to the point of boredom, but the real thing felt utterly different. They were stretching the frontier in more ways than one.
Now her own muscles were noticeably tensing, all her limbs, her jaw, her bowels. She felt nauseous from it. The only sweet thought was that it would soon be over. One way or another. This was just the curtain of terror through which they must pass in order to get where they were going.
"All crew don helmets," said Sable. There was a rustle and a series of clunks as they did so. Dior's world shrunk down to the centimetre or two in front of her nose, inside the faceplate. Leo's voice grumbled over the helmet speakers.
And so it went on, a textbook approach. Leo's was the only voice, apart from Sable's sparse status updates, and the occasional squawk from Hawthorne
But there was nothing out of nominal limits. Just the faintest feeling that the Dragon was jiggling, wavering, as it kissed the edge of the tenuous atmosphere.
"One forty-nine and eight-three-eight."
The deserts and plains craters and canyons of Mars filled the lower three-quarters of the screen, a rich and living painting that drew them into itself. Everything she had seen before: all the VR simulations and false-colour scans, all the telescopic viewings, all paled into frailness against this. The planet had its own presence, its own personality: it had been waiting here for so many millions of years, she thought, and finally here we are. The first.
Sable was humming tunelessly, a habit that came to the fore during demanding tasks which he nevertheless carried out competently. The low sound filled Dior's aural world. "OK folks," he said abruptly in an almost serious tone, "aerobraking should begin in earnest anytime. You all know the drill. No toilet breaks now, I'm afraid. Let's make Bane proud. Leo, splice in our velocity, please."
"Yessir. Just passing one hundred altitude, range nine-twenty, velocity six-point-one and decreasing."
Then, to distant Hawthorne
At about that moment they felt the first bumps, the first faint rumbling of contact with the planet's atmosphere. Despite what Dior knew in her head about the Red Dragon's PICA-X heatshield and the meticulous preparation for the atmospheric braking phase, her body had different ideas and she found that she could not hold her gloved hands still. They trembled. She clenched her fists, clamped them down on the armrests to make them stop. I am not afraid! I am an astronaut! She had done this before in her ESA days, after all, returning from the ISS into Earth's much, much thicker atmosphere. We are simply shedding velocity by transforming our kinetic energy into heat! All the debate about what kind of crew to send to settle Mars: none of them had any military background, none of them were test pilots. This wasn't Project Apollo. It now seemed like a gamble to risk such a mission on people like her, despite her astronaut experience. Somehow just the fact of being many millions of kilometres from the rest of the human race tripled the tension she felt in her limbs. This was not at all like re-entering Earth's atmosphere.
It was impossible not to sense their tremendous speed thrusting them forwards unmercifully as the Dragon delved deeper into the atmosphere, shaking harder and harder until her teeth rattled in her jaw. Mars was squeezing her into the couch. After so long in weightlessness her muscles and joints protested. And the sound – the first sound to come through the walls of their little world since the explosive launch five months before. It was a storm, fleeing past them, grabbing them in its teeth and hurling them away many hundreds of times per second, almost deafening.
It was impossible not to sense their tremendous speed thrusting them forwards unmercifully as the Dragon delved deeper into the atmosphere, shaking harder and harder until her teeth rattled in her jaw. Mars was squeezing her into the couch. After so long in weightlessness her muscles and joints protested. And the sound – the first sound to come through the walls of their little world since the explosive launch five months before. It was a storm, fleeing past them, grabbing them in its teeth and hurling them away many hundreds of times per second, almost deafening.
Dior felt the ballast sled shifting and the cabin tilted a few degrees. The Dragon turned sluggishly and began digging deeper into the atmosphere, using the greater density to shed speed more rapidly. Suddenly it seemed like an incredibly stupid tactic to her as the couch rattled and the weight on her chest and arms grew worse. They were shooting towards the ground, the unyielding rocky terrain. They all knew the system design of the Smaug and how it was intended - on paper - to fulfill the mission requirements. The extra mass they were carrying in the integral trunk, below them, made Dior nervous.
"Sixty k up – four-two-five – and three point four." Leo's voice was strained but clear. He swore in a savage mutter. "We're too low and too short of target. C'mon, Smaug, cut the rate of descent!"
Dior scanned her screen. "Angle of attack is still within limits," she forced herself to say. Even speech became a matter of great effort with this g-force sitting on her.
This moment was familiar, like an enigmatic stranger she had studied intensely many times and was now meeting face-to-face. The descent profile was engraved in her mind, with its unknowns and failure modes marked with large red flags. "We should transition towards horizontal just… about…"
The ballast moved back, far back, and the Dragon curved a scorching path through the wisp of atmosphere. The iron weight squeezing her into the couch shifted, swinging them around, until the Dragon was flying at a shallow angle, still descending, still decelerating. "…Now!"
Sable murmured, "Coming up to engine light-up. Hold on tight."
Before he'd finished speaking, a new force thumped them down, but this one didn't shake to and fro. The Super Draco engines didn't waver or let up. The combined g-force left Dior helpless, unable to breathe except in shallow gasps. She knew this had to go on for about a minute, and she knew the deceleration could only reach about eight gs total, according to the mission design, so she just gritted her teeth. Hah! A crewed descent using supersonic retropropulsion - another first. The thought chuckled around her mind until she remembered the supersonic bow wave that would be squeezing the Super Draco nozzles at that moment. There were still a few top rocket engineers who said that the Dragon would probably explode at this point.
Then it was over, and they could move again. Hugo whooped. "What a ride!"
Dior took stock of their trajectory. Too fast, too low, she thought. No need to transmit that observation back to Hawthorne. Did they need another burn?
Sable took a moment to take in the data. "Lieutenant Dior, what do you think?" he asked. From his steady tone she could sense the rapid analysis that would be storming through his mind. But it was odd that he hadn't already issued a snappy command.
She knew the software should be compensating more. "Possibly on the way down there were some winds we didn't know about, or our absolute positioning is off. There is certainly some large dispersion we weren't expecting. It looks like we're falling short of the target area and velocity is still above the terminal velocity for this altitude. Leo was right – we are a little low. We need a divert maneuver very soon."
"OK, stand by to take manual on my command," he told her. "Terrain relative nav should be cutting in. And the beacons are coming within line of sight."
Leo burst out, "But rate of descent is five hundred metres per second! We need to course-correct now!"
Dior could see that the Dragon's guidance system was correcting for their descent, but seemingly not fast enough. It was a close call, whittling down their altitude right to the red-line safety margin. The descent algorithms had been proven thoroughly before launch, and there were dual redundant systems – two separate computer systems working on the same data simultaneously, so that all three results could be compared. It was hard to doubt the ability of the system to get them down safely, but here they were, straying dangerously from the optimal trajectory.
Then she saw through the guidance system's taciturn efforts: the Dragon had found itself falling short of the landing area, so the software was using their high velocity to get them there, economising on fuel – which carried a high weighting in its algorithms – and risking a lower altitude because the slightly higher-density atmosphere would help to brake them more. Whether or not it would succeed she could not discern. There were too many variables for her.
The angry voice of Leo cut through her thoughts like a welder's torch. "We need manual! Now, Dior!"
"That's enough, Lieutenant," Sable snapped, and she heard a soft click. Had he cut off Leo's voice channel? It wasn't unthinkable. Leo spoke no more. They had run through some short training scenarios like this but they'd always laughed it off as overly dramatic. Even adopting the military ranks had been unpopular at first, but now she knew Sable had been preparing for moments such as this one.
The rate of descent was shrinking reluctantly as the ballast shifted to its limits and the Super Dracos fired one or two bursts, but their altitude was down to about nine kilometres. At this rate they would impact the surface at a shallow angle in thirty to fifty seconds, at a speed of about eight hundred metres per second. Surely the guidance system knew what it was doing.
Sable: I don't think it's pulling up in time. Dior… take manual, please. His voice was mostly-sunny-with-a-chance-of-concern.
Dior's existence, the cramped world of face-and-helmet, seemed to freeze. Had Sable really said that? Was he talking to me? Now she realised his apparent hesitation before: a manual landing was always the last resort. How had they come to this so quickly? Couldn't Control rewind and replay for them?
She looked at her gloved right hand and willed it towards the small joystick set into the armrest of her couch. Light pressure. Like a feather.
It was like stage fright. At this moment, as she breathed in and breathed out, it was utterly unlike the training. Now five other people's lives depended on her. How well had she absorbed all the simulations? Could she keep her head?
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