Space. Stephen Baxter

But the visitors’ centre was still open. The Shuttle exhibit – artefacts, photographs and virtuals – was contained within a small geodesic dome, yellowing with age.

      And there, next to the dome, was Columbia, a genuine orbiter, the first to be flown in space. A handful of people were sheltering from the Florida sun in the shade of her wing; others were desultorily queuing on a ramp to get on board. Columbia’s main engines had been replaced by plastic mock-ups, and her landing gear was fixed in concrete. Columbia was forever trapped on Earth, he thought.

      He found Brind standing before the astronaut memorial. This was a big slab of polished granite, with names of dead astronauts etched into it. It rotated to follow the sun, so that the names glowed bright against a backdrop of sky.

      ‘At least it’s sunny,’ he said. ‘Damn thing doesn’t work when it’s cloudy.’

      ‘No.’ The granite surface, towering over them, was mostly empty. The space program had shut down leaving plenty of room for more names.

      Sally Brind was short, thin, intense, with spiky, prematurely grey hair; she was no older than forty. She affected small round black glasses, which looked like turn-of-the-century antiques. She seemed bright, alert, engaged. Interested, he thought, encouraged.

      He smiled at her. ‘You got any answers for me?’

      She handed him a folder; he leafed through it.

      ‘Actually it was a lot of fun, Malenfant.’

      ‘I’ll bet. Gave you something real to do.’

      ‘For the first time in too long. First we looked at a continuous nuclear fusion drive. Specific impulse in the millions of seconds. But we can’t sustain a fusion reaction for long enough. Not even the Japanese have managed that yet.’

      ‘All right. What else?’

      ‘Maybe photon propulsion. The speed of light – the ultimate exhaust velocity, right? But the power plant weight and energy you’d need to get a practical thrust are staggering. Next we thought about a Bussard ramjet. But it’s beyond us. You’re looking at an electromagnetic scoop that would have to be a hundred kilometres across –’

      ‘Cut to the chase, Sally,’ he said gently.

      She paused for effect, like a kid doing a magic trick. Then she said: ‘Nuclear pulse propulsion. We think that’s the answer, Malenfant. A series of micro-explosions – fusion of deuterium and helium-3 probably – set off behind a pusher plate.’

      He nodded. ‘I’ve heard of this. Project Orion, back in the 1960s. Like putting a firecracker under a tin can.’

      She shaded her eyes from the sun’s glare. ‘Well, they proved the concept, back then. The Air Force actually ran a couple of test flights, in 1959 and 1960, with conventional explosives. And it’s got the great advantage that we could put it together quickly.’

      ‘Let’s do it.’

      ‘Of course we’d need access to helium-3.’

      ‘NASDA will supply that. I have some contacts … Maybe we should look at assembly in lunar orbit. How are you going to keep me alive?’

      She smiled. ‘The ISS is still up there. I figure we can cannibalize a module for you. Have you decided what you want to call your ship?’

      ‘The Commodore Perry,’ he said without hesitation.

      ‘Uh huh. Who –?’

      ‘Perry was the guy who, in 1853, took the US Navy to Japan and demanded they open up to international trade. Appropriate given the nature of my mission, don’t you think?’

      ‘It’s your ship.’ She glanced about. ‘Anyhow, what are you doing out here?’

      He nodded at the Shuttle exhibit. ‘They’ve got my old EMU in there, on display. I’m negotiating to get it back.’

      ‘EMU?’

      ‘My EVA Mobility Unit. My old pressure suit.’ He patted his gut, which was trim. ‘I figure I can still get inside it. I can’t live with those modern Jap designs full of pond scum. And I want a manoeuvring unit …’

      She was looking at him oddly, as if still unable to believe he was serious.

      

      ‘Not ours,’ whispered Xenia. ‘Nothing to do with Bruno.’

      Suddenly Maura found it difficult to breathe. This is it, she thought. This unprepossessing blanket: the first indubitably alien artefact, here in our solar system. Who put the blanket there? What was its purpose? Why was it so crudely buried?

      A robot arm reached forward from the probe, laden with sensors and a sample-grabbing claw. She wished that was her hand, that she could reach out too, and stroke that shining, unfamiliar material.

      But the claw was driven by science, not curiosity; it passed over the blanket itself and dug a shallow groove into the regolith that lay over it, sampling the material.

      Within a few minutes the results of the probe’s analysis were coming in, and she could hear the speculation begin in Bootstrap’s back rooms.

      ‘These are fines, and they are ilmenite-rich. About forty per cent, compared to twenty per cent in the raw regolith.’ ‘And the agglutinate has been crushed.’ ‘It’s as if it has been beneficiated. It’s just what we’d do.’ ‘Not like this. So energy-intensive …’

      She understood some of this. Ilmenite was a mineral – a compound of iron, titanium, and oxygen – that was common in long-exposed regolith on airless bodies like the Moon and the asteroids. Its importance was that it was a key source of volatiles: light and exotic compounds implanted there over billions of years by the solar wind, the thin, endless stream of particles that fled from the sun. But ilmenite was difficult to concentrate, extract and process; the best mining techniques the lunar Japanese had thought up were energy-intensive and relied on a lot of heavy-duty, unreliable equipment.

      ‘I knew it!’ somebody cried. ‘There’s no helium-3 in the processed stuff! None at all!’ ‘None to the limits of the sensors, you mean.’ ‘Sure, but –’ ‘You mean they’re processing the asteroids for helium-3? Is that all?’

      Maura felt oddly disappointed. If the Gaijin were after helium-3, did that mean they used fusion processes similar to – perhaps no more advanced than – those already known to humans? And if so, they can’t be so smart – can they?

      In her ears, the speculation raged on.

      ‘… I mean, how dumb can these guys be? Helium-3 is scarce in asteroid regolith because you’re so far from the sun, which implants it. The Moon is a lot richer. If they came in a couple of astronomical units –’ ‘They could just buy all they want from the Japanese.’

      Laughter.

      ‘But maybe they can’t come in any closer. Maybe they need, I don’t know, the cold and the dark.’ ‘Maybe they are scared of us. You thought about that?’

      ‘They aren’t so dumb. You see any rock-crushers and solar furnaces here? That’s what we’d have to use to get as efficient an extraction process. Think about that blanket, man. It has to be nanotech.’

      She understood what that meant too: there was no brute force here, no great ugly machines for grinding and crushing and baking as humans might have deployed, nothing but a simple and subtle reworking of the regolith at a molecular, or even atomic, level.

      ‘That blanket must be digging its way into the asteroid grain by grain, picking out the ilmenite and bleeding the helium-3. Incredible.’ ‘Hey, you’re right. Maybe it’s extending itself as it goes. The ragged edge –’ ‘It might eat its way right through that damn asteroid.’ ‘Or else wrap the whole thing up like a Thanksgiving turkey …’ ‘We got to get a sample.’ ‘Bruno knows that …’

      Nanotechnology: