Voyage. Stephen Baxter

day. If York had learned one skill in too many hours in college bars and common rooms – she was finishing up her own BS in geology at UCLA – it was how to tune out someone else’s specialty. So she let Mike and Ben talk themselves out, and walked a little way away from them.

      Ben Priest’s son Petey, at ten, was a lanky framework of muscle and energy; he ran ahead of the others, his blond hair a shining flag in the last of the daylight.

      The test site was laid out as a rectangle confined by roads, to the south, and rail tracks, to the north. They were walking out west – away from the control buildings where the car was parked – toward the static test site, Engine Test Facility One.

      This test station was cupped in an immense dip in the land delimited by two great fault blocks: the Colorado Plateau and Wasatch Range to the east, the Sierra Nevada range to the west. The station – with its isolated test stands and bits of rail track and handful of shabby tar-paper shacks – looked overwhelmed by the echoing geology of the desert, reduced to something shabby, trivial.

      They reached the test facility. The assembly was maybe thirty feet high, its geometry crude, complex and mysterious. York made out a sleek, upright cylindrical form enclosed by a gantry, a boxy thing of girders. The stack was scuffed, patchy, unpainted. The whole thing was mounted on a flatwagon on the rail track, hooked up to a rudimentary locomotive. Big pipes ran out of the rig and off to other parts of the test station; in the distance she saw the gleam of spherical cryogenic tanks: liquid hydrogen, she guessed.

      Petey Priest had his face pressed to the fence around the test facility, so that the wire mesh made patterned indentations on his face; he stared at the rig, evidently captivated.

      York watched Conlig and Priest together.

      Mike Conlig was a native Texan. At twenty-seven he was a little shorter than York; his build was stocky, his engineer’s hands callused and scarred, and his jet-black hair, which he wore tied back in a pony-tail, showed his Irish extraction. Just now, a slight paunch was pushing out his T-shirt.

      York had met Mike half a year ago, at a party at Ricketts House at Caltech, which was a half-hour drive from UCLA. York had gone out there on a kind of dare; women weren’t admitted to Caltech. Natalie enjoyed his fast, lively mind, his genuine readiness to respect her for her intellect … and the compact muscles of his body.

      She’d finished up in bed with Mike within a couple of hours.

      Mike was quite a contrast to Ben Priest, she thought, looking at them together.

      At thirty-one, Ben Priest was tall, wiry, and with an ear-to-ear, kindly grin. He was a Navy aviator with a dozen years’ experience, including two at the Navy’s prime flight test center at Patuxent River, Maryland – and, since 1965, he’d been a NASA astronaut, although he hadn’t yet flown in space.

      York knew Mike and Ben had struck up a close relationship since Ben’s assignment here as astronaut representative on the project. She’d no doubt Mike was throwing himself into the camaraderie of the station here – guys together in their prefabricated shacks, at the frontier of technology, playing with NERVA all day, and knocking back a few each evening.

      It was having a visible physical effect on Mike, she thought, if not on Ben …

      Security lights were coming on all over the nuclear test rig now; they made it into a sculpture of shadows and glimmering reflections, an angular, deformed representation of a true spacecraft As if the ambitions driving the men and women who worked here had actually shaped the geometry of the place, making it into something not quite of the Earth.

      While he was talking to Priest about the day’s events, Mike Conlig tried to keep a hawkeye on Natalie. She was gazing around the plant. Natalie was a little too tall, slim, intense, her hair jet-black and tied back; right now, those big Romanian-peasant eyebrows she hated so much were creased in concentration.

      This visit was important to Conlig.

      Strictly speaking, he and Priest were breaking NASA and AEC regs by bringing her here, to see their work close up; and certainly a kid like Petey shouldn’t be allowed here. But regulations got replaced by realism in a place as remote as this. We’re all good old boys together out here, he thought.

      Anyhow, he was keen to show Natalie this place: where he worked, what he did with his life. It was worth breaking a few rules to achieve that. He wanted Natalie to see Jackass Flats through his eyes.

      Natalie’s head was habitually full of suspicion and disapproval of Big Government Science like this. But the world looked different to Conlig. To him, this shabby test site was the gateway to the future: to other worlds, colonies on the Moon.

      Even Mars itself.

      Ben Priest was trying to explain the test rig to Natalie. He made her look more closely at the object inside the gantry, trying to get her to make sense of it. A nozzle, gracefully shaped, flared from the top toward the sky …

      ‘Oh,’ she said. ‘I’ve got it. It’s a rocket. There’s the nozzle, at the top of the stack. It’s a rocket, on its launch gantry. Gee. Just like Cape Kennedy.’

      Ben Priest laughed. ‘Except it’s upside down.’

      ‘One day we’ll see this at Kennedy,’ Conlig said, aware he sounded a little defensive. ‘One day soon. Its descendants, anyhow; this poor bird is never going to fly.’

      ‘This is actually a late generation engine,’ Ben said. ‘Our newest pride and joy. The XE-Prime: quite close to a flight configuration. The first rigs here, ten years ago, were called Kiwis.’

      ‘Oh,’ York said. ‘Flightless birds.’

      ‘Now,’ said Ben, ‘there are a string of projects working under the generic title NERVA. For “Nuclear Engine –”’

      ‘“– for Rocket Vehicle Application.” I know.’

      ‘But we’re still restricted to building flightless birds,’ Priest mused. ‘We’re proud of this baby, Natalie. We’ve managed to get close to fifty thousand pounds of thrust with her. And we managed twenty-eight restarts. Reliability is going to be a key factor in long-haul space travel …’

      Conlig watched Natalie, trying to gauge her reaction.

      All of six years older than Natalie, Conlig had finished his PhD – on exotic, heat-tolerant refractory materials for lightweight fission reactors – in a near-record time.

      Conlig was certain – so was Natalie, come to that – that he was heading for the top of his chosen profession. And since, if Spiro Agnew could be believed, nuclear rockets were going to be the Next Big Thing in space, that top could be a very high summit indeed. Meanwhile, York’s geology was likely to take her away for months at a time. Their relationship was going to be odd, to say the least.

      It was odd to know that his whole life might be shaped by the success, or failure, of a nuclear rocket. I really am living in the future, he thought.

      To Conlig, nuclear rockets were the simplest, most beautiful machines in the world. You didn’t burn anything, like in a Saturn. You just heated up high-pressure liquid hydrogen in a reactor core, and let hot gas squirt out of the rear of your ship.

      A nuclear upper stage would uprate a Saturn V by a factor of two: Moon payloads could be increased by more than half.

      But there were major technical challenges.

      The working fluid was liquid hydrogen at twenty-five degrees above absolute zero. Once it was pumped to the reactor the hydrogen had to be flashed to above two thousand degrees.

      Cooling systems were Mike Conlig’s specialty.

      There were other difficulties. Like, if you were looking at space applications, there was the need to shield the crew from radiation. And the fact that you couldn’t cluster too many of these babies in a given stack, because their neutron emissions interfere with each other, and, and …