When the Cronus finally reached the elevator hub, the first step was to anchor together the two massive bodies, hub and ship, with rigid struts. Then transparent tunnels were attached to airlocks, through which passengers and freight could pass in either direction – tunnels through the vacuum.
When that was done, they all had to be brought off the ship, John Smith learned, in order to give the maintenance crews and their bots the room to work – and for the refit of Cronus with its new fusion propulsion system. Already small ferry craft had come sailing out to empty the ship’s hold, and crew and specialised machines had begun dismantling its now-outmoded fission-powered engine.
It didn’t take long for John Smith to pack up the gear he would need during his brief stay on the hub. Most of his already modest bundle of possessions would stay on the ship, to which, of course, he would return after its fitting-out for its even more extraordinary journey onwards.
The passengers were taken off in small groups – small so as not to overcrowd the facilities of the elevator hub itself. Which wasn’t nearly so roomy inside as it had seemed from outside, Smith learned when he got there; the habitable spaces were swathed in layers of ice-fragment impact shields that were thicker than he had realised.
Still, there was a zero-gravity melee as the Cronus passengers were shepherded through a final security and quarantine barrier and into the reception areas.
And it was during the crowding of the debarkation process that Smith ran into Elizabeth Vasta.
Smith hadn’t seen Earth’s top science adviser since she had put herself into cryosleep only weeks after the launch. Now her black pearl pendant, a relic of life from Earth, gleamed in the pale light of Saturn, as she casually gripped a rail to keep from floating around.
She grinned at him. ‘So, John, good to see you. Good long sleep?’
‘Not so deep or so long as yours.’
‘I do have a twinge of guilt at not keeping you company. Although I do know you Conserver types are a little anti-social.’
He frowned at that. ‘I’d prefer, reserved—’
‘Reserved or not, here you are, Mr Smith.’
A tall, gangling man in a crisply creased coverall approached them. Shoulder flashes, John observed. An officer.
‘And, as the most distinguished guests among this shipload, Professor Vasta, Mr Smith, I’m here in person to tell you you’re very welcome. I’m Emmanuel Caspar. Commander of this installation. Please, come this way.’
After perfunctory handshakes, Caspar led them with easy pulls along hand rails on a slow zero-gravity traverse through corridors still crowded with passengers and station crew.
Pale, with thinning red-brown hair, maybe mid-thirties, Caspar looked friendly in a professional sort of way, Smith thought.
Caspar said now, ‘Formally, I’m a commander in the United Earth Air Force – as you probably know …’
They had known. Caspar’s coverall was a lighter blue than the standard issue to the crew at the quarantine barrier, Smith noticed now, maybe a sign of rank. He thought Caspar had an accent Smith had learned, in his time on Earth, to call European English – the light tang of a language familiar but not one’s own.
All the while Caspar led them on, he was evidently sizing them up, and their fellow passengers. Smith had the feeling that one false step would have this Commander Caspar throwing them in a cell with little compunction. But then this station was far from home and an obviously fragile habitat, so lifeboat rules must apply, and commanders and captains had to be harsh when needed.
‘I’ve had the luggage you’ll need while on the station sent to your rooms.’ Caspar grinned. ‘Including your chess set, Mr Smith. A luxury?’
‘John, please – how would you know that? Oh, the cargo manifests.’
‘I always do a search, to find players among newcomers. My son Fabio plays the game. I don’t, sadly, or not well enough – not since he passed the age of five. Ten years old now. And not enough chess played here. Maybe you could catch up with him some time?’
Vasta seemed surprised at that. ‘Your son is here?’
‘Plenty of families up here, Professor Vasta. The station is fifteen years old already, though the methane extraction operation hasn’t been operating that long. And I’m sorry to be hurrying you, but there are some pretty unique things you need to be shown while we have the chance …’
A spatter of red lights lit up on the ceiling and walls, and a softly spoken voice issued an evidently automated warning. And then came a loud, multiple clang that made Smith start.
Caspar didn’t lose his rhythm. ‘That’s just the decoupling,’ he said, shepherding them along. ‘Nothing to worry about. The Cronus detaching from the hub – already, and on time, I’m glad to say: we are keeping to an aggressive schedule to get this project done. Cronus is straight off to the jig factory for her refitting. For now she’s not accessible, but don’t worry, your ride onwards is in good hands. But first—’
They came to a lounge, hardly a tenth as spacious as some of the big spaces aboard the Cronus, Smith thought, but comfortable enough – certainly for a man used to Conserver chic.
But the view out made up for the lack of room. Or rather the view down, through a crystal-clear floor.
In this lounge there were chairs fitted with loose belts, and bars for legs to wrap around, and glass tables with covered bowls of some kind of snack, and bottles and flasks all held in place by clips and straps. A zero-gravity lounge, like those on the Cronus. But as they sat, Smith saw immediately that you were meant to sit at these glass tables and look down through the transparent floor.
Where the clouds of Saturn roiled. The ring system, seen edge on, was that now-familiar straight-line scratch across the sky.
And, looking down, hanging here above the air, Smith immediately picked out the elements of engineering that justified the routine existence of this place. He saw a fine line arrowing down into those clouds, evidently the space elevator cable itself – or rather cables, several of them, presumably some for lifting and lowering, some for power transmission, others as some kind of emergency backup perhaps. Cables made by humans and their machines, anchored by a knot of industrial technology, and plunging down through the rings and into the air of the planet.
Smith had seen Earth’s space elevator. This huge structure, mining the clouds of a gas giant, dwarfed anything terrestrial. It was an audacious concept from this angle, a remarkable sight – thrilling, even for an instinctive Conserver.
Caspar let them just look for a few moments. Then he opened a small cupboard under the nearest table. ‘Champagne? Coffee? Both? Captain’s privilege …’
Neither Smith nor Vasta felt like talking, evidently, as Caspar served the drinks in bulb flasks. Sitting here, Smith did feel oddly exhausted, in fact – some combination of his extraction from an environment he had been stuck in for six years, the shock of new faces … Conservers were supposed to live quietly, he reassured himself.
The champagne felt flat, and the coffee lukewarm.
Vasta too was a little subdued, though she was better at hiding it than Smith, he thought.
Caspar was sensitive enough to see their reactions, and rather than force them to converse he took the lead. ‘I know how it feels to be suddenly suspended in all this – spectacle. Overwhelming. And the scale of it is profoundly un-Earthly. But it soon becomes business as usual. I was mostly ground-based – I mean, Earth-based – before I applied for this job. It requires more diplomacy than many postings, what with representatives of so many agencies, nationalities, corporations, all working, living and playing up here. And specialists from cable engineers to biologists looking for life in the clouds. As for the military side, I can leave that to the lower ranks save in emergencies.
‘Life here isn’t as comfortable as it might be. This is an outpost, far from home. But people do live here. This is my twelfth year on the station, fifth as commander. We get by. My own son is here – Fabio—’
Smith smiled. ‘The chess fiend.’
Vasta looked at Caspar more closely. ‘His mother too?’
‘Afraid not. She left a few years ago – on one of the regular transports. There have been more of those recently; a lot more propulsion engineers and related workers have been brought here for the rebuild of Cronus, as you can imagine. And a lot of planetologists and other specialists have been sent back to Earth to make room, mostly volunteers. Lynette … was never happy here. The confinement, I think. Whereas I—’ He waved a hand. ‘I think I’ve found a role here.’
Vasta said, ‘But – Fabio, was it? What of him?’
‘We gave him the choice. To stay or go—’
‘He had to choose his father or his mother? At, how old, seven, eight?’
Caspar looked increasingly uncomfortable, but he was standing his ground. ‘We are a deep-space society now, Professor Vasta. Such dilemmas are hardly unique. Why, separated families may become the norm in the future – but the sooner we get faster links between the planets, the more human the Solar System will become, those family ties less disrupted. But as to the present project …’ He turned to look out of the windows. ‘How could I give up all this? And the chance to work on a ship like Cronus, on such a mission?’
Vasta and Smith exchanged a glance. That was the end of that topic, Smith thought.
They followed Caspar’s lead in turning back to the windows.
Caspar went on, ‘I wanted to bring you straight up here to view the scene of the crime, as it were. Orientation. Because the station at the other end of this tether is collecting what you’ve come for.’
Smith peered down. Now he saw clusters of tanks, in hexagonal arrays, attached to the cable along its length, each slowly ascending from or descending into the clouds of Saturn. ‘Ah. That’s the helium-3 for the Cronus, is it? The fuel for its fast mission to Planet Nine.’
Caspar nodded. ‘Well, along with other useful gases. In normal operations, of course, the Cronus crew would already be taking on board the methane propellant they would need for the long, six-year journey back home to the inner System – and we would have already hauled that up the elevator cable from the clouds below. Now we are extracting the helium-3 that will enable Cronus to go much further and faster, to reach Nine in a reasonable time. But even after this mission, the helium extraction process is going to be a bootstrapping arrangement that could lead to very large industrial complexes here indeed – and ultimately transform the prospects for Earth itself.’
Vasta nodded. ‘The Kardashev project … I’ve heard of that. Still a long way off.’
‘True. For now. Of course everything we do needs power, and even out here it all starts, in fact, with the Sun.’ He pointed upwards.
Smith and Vasta looked up now, through a transparent section of the roof. And Smith saw what looked like a flower, a stalk with petals, shining dimly in the low sunlight – or rather he saw one edge of such a structure. Huge in scale, evidently.
‘Solar energy capture?’ Vasta said.
‘Correct. We are ten times as far from the Sun as Earth, so – inverse square law – you need a hundred times the area of solar cells to capture the equivalent power. But we have the room for that. This isn’t the crowded low orbit of Earth … That solar sail, around two kilometres across, was built for the operation of extracting methane from Saturn’s atmosphere – for now. Soon we will be switching over to the helium-3 extraction, of course.’
Vasta frowned. ‘I can’t do the math in my head. I’ve probably slept too much the last six years … A power plant that size ought to yield about twenty megawatts, with decent efficiency?’
‘About that.’
‘And the methane extraction rate?’
‘Not so easy for you to guess, I’d think,’ Caspar said. ‘But maybe faster than you might suppose. We believe we’ve a smart design in terms of exploiting the environment down there.
‘The cloud composition changes with depth, you see. In the uppermost layers you have mostly ices, ammonia, along with traces of water, methane. But hydrogen and helium are both gases. To get at the methane easily, we send our miners a few kilometres deeper into the air, where the temperature rises a little, and we come to a sweet spot where the temperature is about a hundred and sixty below the freezing point of water, pressure about seventy per cent Earth’s atmospheric pressure. There you have an environment where hydrogen and helium are both gaseous, and ammonia and water are both ices – but methane forms liquid droplets. So all you have to do to separate out the methane is to collect the only liquid component at that level. In fact the energy we need to lift the methane out of the deep atmosphere is the main cost – even though to sieve out one kilogram of methane you have to process over two hundred kilograms of air.’
‘Very elegant,’ Smith said. ‘But now you’re switching over to extracting helium-3. Which I imagine is more of a challenge.’
‘True. But we’ve already had six years, since your launch from Earth, to figure out a way. And, given how crucial helium-3 is going to be to the Earth’s economy some day, even aside from the Cronus mission – so I’m told—’
He glanced at Vasta, who nodded.
‘The principle is the same. We just need to go deeper into the atmosphere. Helium-3 is as abundant here as it is anywhere in the Solar System. Far more abundant than on the Moon, of course. But still to extract a kilogram of that stuff from the clouds you have to process, not two hundred kilograms of air as with methane, but six hundred tonnes of it. In this scenario the energy cost of extraction from the air is much larger than the lift to orbit costs – three times as much. But, hey, the solar energy is free. As I understand it, for a return trip the Cronus will need around five hundred kilograms of fuel, which will have taken us a hundred days to extract, allowing for inefficiencies, given our twenty-megawatt power plant. Some of it we already have in store.’
Vasta nodded again. ‘I do know they’re going to take a lot longer than that to fit out the Cronus for this halfway-to-the-stars trip, in your improvised shipyard.’
Caspar said, ‘But it has to be done. To get to deep space. I fully accept the logic of the mission. We have to get boots on the ground out there. We know the situation out at Planet Nine is – compelling, if not urgent.’
Vasta snorted. ‘Compelling? More than that. If it has anything to do with the quasar and the effects on Earth – yes, getting us out there is damn urgent.’
‘I do understand,’ Caspar said calmly. ‘Which is why we’ve got started already. Come, follow me. There’s a better view from another lounge. We are quite the nest of engineers here, always busy …’
He pushed out of his chair, and Vasta and Smith followed.
It was a tough little trek. Caspar set a fast pace through a maze of corridors, and Smith felt that both he and Vasta tired quickly. Should have slept less and exercised more en route.
But aside from that it was bewildering to be in a new place after so long confined to the ship, large as that great vessel had been. Not only that, as they approached the apparent destination, there were crowds to push through, both of Hub staff and Cronus crew, busy, Smith supposed, with the handover of crew to fusion-propulsion engineers.
But Caspar was the base commander, and people magically cleared out of his way, especially with two high-status guests in tow. That magic still worked when they got to the observation lounge he wanted.
And when the guests were delivered before another big picture window, Smith immediately saw what he meant by a better view.
‘That,’ Caspar said, ‘is what my teams call a jig factory …’
Saturn below, starry sky above, the brilliant, perfectly flat line that was the ring plane edge-on. And there, hanging in space, a few kilometres away – magnified by the window – Smith saw the Cronus, that now-familiar dumbbell configuration.
He reminded himself just how big the thing was: the two large spheres each more than a hundred metres in diameter, the total ship length a third of a kilometre. But there were other components drifting in space now, besides the main hulk, some of them huge themselves.
And the ship as a whole was moving, but evidently not under its own propulsion system. Smith saw little sparks of light coming from small ferry craft, now docked with that enormous hull – a fix-up to enable precise short-term manoeuvring. People were moving around the hull too, some in suits with long, fragile-looking umbilicals, some flying independently with flaring backpack rockets. From this distance they looked like ants. Flying ants. Or glow worms perhaps, he thought.
And this industrial swarm was guiding the huge ship into an even larger form, a rough rectangular frame of struts and girders, longer than it was tall. A box big enough to hold an interplanetary spacecraft.
Caspar watched his guests, grinning. ‘That, my new friends, is a jig factory. Essential bit of kit for assembly in space – or disassembly. Keeps everything lined up, you see, in the absence of gravity, as you put it all together. I’ve seen this kind of manoeuvre before. Never palls. Beautiful, isn’t it? In its way. An elephantine ballet.
‘Well. I think that’s enough for today. Shall I show you to your rooms?’
It took only a month for the Cronus to be refitted with its new fusion-fuel interplanetary engine. John Smith saw it all.
And, aboard the Consortium ship Aquila, Jeorg North, glaring into high-definition scopes, was there in time to see it finished. Or should have been.