Voyage. Stephen Baxter

aeronautical research center in the US, and it was father to all the rest. It had been founded during the First World War, conceived out of a fear that the land of the Wright brothers might start to fall behind the European belligerents in aviation. It had been a different world, a world in which the individualistic traditions of old America were still strong, and there was a great suspicion of falling into the emerging technocratic ways of the totalitarian powers of Europe.

      Langley stayed poor, humble and obscure, but it succeeded in keeping abreast of the latest technology. And back then – Gregory had told Jim – Hampton was a place where people still referred to the Civil War as ‘the late war.’

      Gregory had often taken Jim around Langley. The Research Center was a cluster of dignified old buildings, with precise brickwork and extensive porches, that looked almost like a college campus. But, set amongst the neatly trimmed lawns and tree-shaded streets, there were exotic shapes: huge spheres, buildings from which protruded pipes twenty or thirty feet wide. These were Langley’s famous wind tunnels.

      Jim Dana had come to identify the layout of Langley – the odd mixture of the neatly mundane with the exotic – with the geography of his father’s complex, secretive mind.

      Hampton was so isolated that a lot of bright young aeronautical engineers didn’t want to come within a hundred miles of the place. Those that did come to Langley tended to be highly motivated, and not a little odd – like Gregory himself, Jim had come to realize ruefully. And the local Virginians hadn’t thought much of the ‘Nacka Nuts’ arriving in their midst – as they still called them even now. So the Langley engineers had kept themselves to themselves most of the time, on and off the job, and Langley had evolved into its own peculiar little world.

      As Dana had grown and moved away, he’d become aware of the bigger world beyond Virginia.

      ‘I don’t know why you stay here,’ he’d once told his father. ‘All the real action in NASA is at other sites. Why don’t you ever think about moving away?’ He couldn’t figure his father’s lack of ambition.

      ‘Because things don’t get any better for people like me than they are here,’ Gregory had replied. ‘The press don’t care much about Langley. Even the rest of NASA doesn’t care much. To the outsider, the place is just a set of gray buildings with gray people working slide rules and writing out long equations on blackboards. But if you’re in love with aeronautical research, it’s a kind of heaven – a unique and wonderful place.’

      Jim knew that Langley had made immense contributions to the US’s prowess in aeronautics and astronautics. It had got involved with the development of military aircraft during the Second World War and then in the programs which led to the first supersonic airplane, the Bell X-1. Langley staff had formed the task force which had been responsible for the Mercury program, and later it got involved with studies for the optimal shapes for the Gemini and Apollo ships …

      Gregory never talked about his past. Dana knew he’d suffered during the war. Maybe, he thought, Langley was kind of a refuge, after all that. It buffered him from the pressures of the competitive aircraft industry, and on the other hand from NASA politics. It was as if the men of Langley – and they were men, almost exclusively – had made a kind of unconscious decision that their site and budgets and scope should remain small, even as the space program Langley had spawned had grown like Topsy.

      Gregory was still only forty-one. But Dana could see, now he’d grown a liitle more, that Gregory had found a place that suited him; and here he was going to stay, getting older and slower, charming everyone with his lingering traces of French accent, working at his own pace inside this peaceful, isolated cocoon.

      Staying at Langley meant, though, that Gregory and Sylvia were more or less stuck, here in downtown Hampton, on Gregory’s plateaued-out salary; and here they’d probably have to stay, despite the inexorable decay of the neighborhood …

      Gregory had drawn a half-ellipse which touched Earth’s orbit at one extreme, and reached out to kiss Mars’s orbit at the other. ‘Here we have a minimum-energy transfer orbit. It is called a Hohmann ellipse. Any other trajectory requires a greater expenditure of energy than this … To return to Earth, we must follow a similar half-ellipse.’ He moved Mars around perhaps two-thirds of its orbital path, and drew another kissing ellipse, this one out of Mars and inwards toward the Earth. ‘The flight home takes just as long as the flight out, around two hundred and sixty days. And in addition, we must wait all this time at Mars, until Earth and Mars have moved into the right configuration for us to return: for no less than four hundred and eighty days. And so our mission time is a remarkable nine hundred and ninety-seven days: more than two and a half years. Our longest spaceflight to date has been around two weeks; we surely can’t contemplate a mission of such magnitude.’

      ‘And yet, Rockwell are studying just such a mission profile, for NASA,’ Dana said. ‘Chemical technology only. And at Marshall they are looking at nuclear options.’ Nuclear rockets, more powerful, could put ships into shallower, more direct ellipses. ‘The Marshall study is showing journey times of no more than four hundred and fifty days, total …’

      ‘More big rockets! Huh!’

      Dana grinned. ‘Still not elegant enough for you, Dad? But where’s the room for elegance in all this? It seems we’re kind of constrained by the laws of celestial mechanics. It’s either Hohmann, or brute force.’

      ‘Exactly. So the elegant thing to do is wait: wait until we’ve developed a smart engine, like an ion drive, which can really cut down the transit times. But that won’t come in my lifetime, and maybe not yours.’

      ‘Humm.’ Dana took the chalk from his father, and drew more concentric circles. ‘Of course, you didn’t show the full picture here. There are other planets in the system: Venus inside Earth, Jupiter beyond Mars. And the others.’

      Gregory scowled. ‘What difference does that make?’

      ‘I don’t know.’ Dana dropped the fragment of chalk back into his father’s pocket. ‘You’re the specialist.’

      ‘No, no, this is not my field.’

      ‘Maybe there is some way to use the other planets, to get to Mars. There are NASA studies going on of a Grand Tour: using the gravity field of Jupiter and the other giant planets to accelerate a probe out to Neptune …’

      ‘So what are you suggesting? That we fly to Mars via Jupiter? That’s ridiculous. Jupiter is three times as far from the sun as Mars is.’

      This tone – hectoring, impatient – was all too familiar to Dana. He held his hands up, irritated. ‘I’m not suggesting anything, Dad. I’m just chewing the fat. The hell with it.’

      But Gregory continued to stare at the board, his eyes invisible behind the layer of chalk dust on his glasses. Some remark of Dana’s had sent him off, like a Jules Verne impulse, on some new speculative trajectory of his own; Jim Dana might as well not have been there.

      The hell with it, he thought. I have my own life now, my own concerns. I don’t have time for this any more.

      Maybe I never did.

      Dana withdrew from the workshop, brushing the dust off his jacket, leaving his father to his thoughts.

      He spent the rest of the afternoon with his mother. They sat on the swing seat back of the house, drinking home-made lemonade and talking in the warmth of the sun. In the distance, seagulls cried.

      Gregory Dana carefully sketched interplanetary trajectories.

      … At age fifteen, in the year 1944, Gregory Dana was no rocket engineer. In fact he was no more than garbage, just one of the thirty thousand French, Russians, Czechs and Poles who toiled inside a carved-out mountain in Thuringia.

      Everything was slow – even dressing was slow – and Dana was already hungry by the start of his work at five a.m. And yet he would receive nothing until his soup, at two in the afternoon.

      And