And so, here she was. She had slapped a softscreen on the wall, and as she worked she listened to a message from her parents, relayed from their home in Cambridge, England. She didn’t trouble to watch too carefully; the quality was low because of reduced capacity anyhow, and her father was prone to providing her with badly-shot home movies overlaid by her mother’s slow, monotonic speech. Right now, for instance, there was a shaky pan of the new rice paddy fields around Ely in Cambridgeshire.

…You remember your cousin Sarah,her mother said. Came down with CJD, didn’t she. She was only twenty-two. Such a pretty girl. She chose the euth clinic, you know, even though Mary — your aunt Mary, you know, her mother — said it was un-Christian, What a mess the whole thing is. Of course we don’t have blood donors now, all our transfusion blood is flown in from abroad, and the Tories say the government’s blood tax is too high. Quarantine, they call it. The French were the first — typical bloody French, your father says — when they poured all that concrete down the Channel Tunnel. Oh, John Major died. There was a program on the telly. I didn’t realize he was the last Tory Prime Minister, who’d have thought it…

Her mother’s face, on screen now, was a ruin, the left side imploded, cratered. She had come down with a prion disease related to Creutzfeld-Jakob, non-fatal but disfiguring, the prions steadily sculpting the soft cells of her flesh.

It had taken Mott herself a hell of a lot of tests to be proven fit to come to the States, to get into NASA.

She had come a long way from Cambridgeshire.

…Everything was different here.

Discovery was now five hundred million miles from the sun — five times the distance of Earth from the parent star. As the mission had unfolded the inverse square law had worked inexorably at the sun’s radiation and size; from here the sun was still brilliant — at magnitude minus seventeen, much brighter than any star or planet seen from Earth — but its disc was tiny, like a flaw in the retina, like a distant supernova, like nothing she had seen from the surface of Earth. The light it cast had a strange quality, too: almost the light of a point source, the shadows stretching over the orbiter long and sharp.

Even the sun was different here, transmuted into something alien by distance.

As Discovery’s separation from Earth had grown, and the lag of radio signals from Houston had risen to an hour and a half round trip, it was as if their tenuous link to home had stretched, broken.

Now Earth was just a spark of blue light close to the shrinking sun, the place the high-gain antenna pointed. And those remote voices, from Mission Control and in the back rooms of Building 30 at JSC, with their detailed reams of advice and instruction — trying to control the crew, as once they had choreographed Moonwalkers, step by step — seemed to have little to do with their situation, here, suspended in extraordinary isolation in this outer darkness.

It was taking a while to sink in, after four decades of the culture of the ground control of spaceflight, but out here, as they sailed past the moons of Jupiter, the crew of Discovery was truly alone. There was nothing to fall back on but what they had brought along with them, for better or worse, and whatever ingenuity they could apply.

Your father’s talking about a holiday. He wants to go to Mega-Power — you know, the turbine tower, that Dutch monstrosity in the North Sea. Apparently they have restaurants and a hotel and shop, four miles high. All covered over, of course. Fancy that. But I wouldn’t trust it, not after the leak of that huge cloud of ammonia last year…

Directly above her head Mott could see the half-disc of Jupiter. It glowed salmon-pink in the flat sunlight. Discovery was coming no closer than two million miles to the planet — twenty-five Jupiter diameters — but even so the giant world showed a sizable disc, like a big pink coin held at arm’s length, four times the size of the Moon in Earth’s sky. On the sunlit hemisphere she could make out the stripes of the ammonia ice cloud bands, brown and white and orange stripes, streaked and curdled with turbulence along the lines where they met. She couldn’t see the Great Red Spot, and that was a disappointment. But Jupiter’s day was only ten hours or so; perhaps the planet’s disc would stay visible long enough for the Spot to be brought into view.

And Mott could see some of Jupiter’s moons, strung out in a line parallel to the equator of their parent.

Io — a little larger than Earth’s Moon — lay between its parent and the sun, about two Jupiter diameters from the cloud tops, its illuminated hemisphere a sulphur-yellow spot of light. Ganymede, twice as far from Jupiter as Io, sat behind its parent, its ice surface glittering white. Europa and Callisto, the other large moons, were harder to spot; eventually she found Callisto as a bright white spark against the darkness of Jupiter’s shadowed hemisphere.

It only took Io, the innermost of the large satellites, a day or so to travel around its orbit around Jupiter. If she stayed up here long enough, Mott would get to see the moons turn around their parent in their endless, complex dance…

The compact Jovian system was oddly charming. Like an old-fashioned orrery, a clockwork model of the Solar System. But Jupiter was eleven times the diameter of Earth. And its moons, if freed from Jupiter’s grip, were large enough to have qualified as planets in their own right. Ganymede — out here, a spark dwarfed by Jupiter — was the largest moon in the Solar System: larger than Titan, larger, in fact, than the planet Mercury.

In a window frame of this beat-up Shuttle orbiter, she could see five worlds, clustered together in one gigantic gravity well.

But, she thought, there was no life here, not even — as far as anyone could tell — on that slush ball Europa. There was no life for a half-billion miles in any direction, save within the battered walls of this spacecraft, the bubble of air which sheltered her.

Damn it all. She wished Siobhan could see this. That remote death, back in the heart of the Solar System, was losing its power to hurt her now. But still, what a waste, what a meaningless, cruel waste.

No, I want to go to the hedgerow museum in Hampshire, Apparently they still have some ptarmigans there, the last ones. Oh, I have to tell you, you wouldn’t believe the price of potatoes in the shops. All the sweetcorn you could ask for, but it’s not the same… We know you are still missing Siobhan, love. We know you two were pals. You take care of yourself, and try not to fret about it all too much…

Pals. Her parents had never known — or had preferred not to know — about Libet’s true relationship with their daughter. Her parents had been young in the 1970s, hardly the Victorian era. Mott wondered if there was something in the human genome which dictated that no generation could accept the sexuality of its offspring.

But, out here, it hardly seemed to matter, like so much else.

Discovery’s path — whirling around the inner planets, and then out past Jupiter to Saturn — was actually similar to that of Cassini, which had come this way more than a decade before. But since then Jupiter and Saturn had wheeled through their grand orbits, of twelve and twenty-nine years, and they weren’t in such a favorable position for Discovery’s slingshot as they had been for Cassini. Discovery needed to come in a lot closer than Cassini, to extract still more energy from Jupiter, the most massive planet in the Solar System.

But that meant the orbiter had to penetrate deep into Jupiter’s magnetosphere.

Mott knew she, and the rest of the crew, were paying a price. Jupiter’s magnetic field was ten times as powerful as Earth’s, and its magnetosphere — the doughnut-shaped belt of magnetically trapped solar wind particles — stretched fifty Jupiter diameters, far beyond Discovery’s current position. Right now heavy solar wind particles, electrons and hydrogen and helium nuclei, which circled, trapped, in Jupiter’s magnetosphere — ten thousand times as energetic as those in the Van Alien belts of Earth — coursed through the fabric of the ship, and her body.