She anchored herself over her table, and prepared what she would say.

…In the ninety days since it had been pushed out of orbit by its solid-propellant injection engine, Tianming had coasted slowly away from Earth, heading outwards from the sun. It had dogged the heels of the home planet, she thought, as a dog will track its owner. Thus she had drifted more than three and a half million miles from Earth, and when the Tianming’s slow thermal roll brought the small viewing window into the right direction, she could see Earth and Moon together: twin crescents before the huge glare of the sun, the smaller brown alongside the fatter blue-white, so close to each other she could cover up both Earth and its satellite with the palm of her right hand, upheld before her.

And there was her theme.

She said: “It is precisely three thousand, nine hundred and sixty-seven years since Chinese astronomers witnessed an extraordinary heavenly event.

“The motions of all five naked-eye-visible planets brought them together in the sky. Above the crescent Moon at the horizon, Venus, Mercury, Mars, Saturn and Jupiter were strung out like lights on some celestial road, near the great square of Pegasus. That unique conjunction must have been a transfixing event. It was the beginning of the planetary cycles of our ancient astronomers.

“There has been no other time in the last four thousand years, and there will not be in the next four thousand, when such a spectacle will be visible again. But I am reminded of it now, as I study the Earth, Moon and sun framed together in the window of my capsule. How appropriate it is that a Chinese person should be here, to witness this unique conjunction!”

The joy in her voice was unfeigned. Jiang Ling was happy and proud to be here. She said that in her broadcasts, and she meant it.

The habitable compartments of Tianming were small, confining. The craft was improvised, of course, and much of its mass besides was given over to the weapon and its support systems, rather than to her comforts. But she was comfortable here, in this little spinning metal shell in space, and she was not given to claustrophobia.

Her mother told her she was happy in space, and nowhere else. It was true.

Sometimes it struck her as remarkable, however, how everything in the Universe had become separated into two distinct categories, characterized around herself: within a few feet of her body, contained in this compact craft, or else they were millions of miles away.

She continued with her broadcast, and other duties.

Her shelter in space consisted of cylindrical compartments, strung together along a common axis, like a collapsible telescope. Its curved hull was swathed with a powder-white insulating blanket, which shone brightly in the sun. Three huge solar panels were fixed around the module’s widest section; they could be swivelled, like the faces of flowers, to trap the sunlight, and they were covered with cells, big black squares neatly aligned.

The smaller cylinders were used for docking with ferry craft and experimental work, and they were crammed with storage lockers, science equipment and control panels. The main body of the craft was called the working compartment, some fourteen feet wide.

There was a small table at which she could sit, by wrapping her legs around a rudimentary T-shaped chair. There were control and instrument panels, and command and signal equipment of the type used in Lei Feng spaceships. There were a number of work positions, where she could take measurements of such items of scientific interest as the interplanetary plasma environment surrounding the ship. There was a single, rather small porthole. During the cruise, the Tianming was rolled, continually, to ensure a uniform heating by the sun’s rays; this had the effect of limiting her useful observations.

To the left and right of the workstations there were controls for the craft’s basic systems: air regulation filters and pumps, temperature and humidity controllers, as well as more equipment and bio-medical research apparatus.

There was a small galley area, with enough supplies, she was told, for a mission of one hundred days, with a small margin. There was an exercise cycle into which she could strap herself. Her orders were to use this for no less than three hours a day, in order to reduce the risk of muscle wastage and bone erosion.

Beyond the working chamber, inaccessible to Jiang, was a small hemispherical module containing rocket motors and propellant tanks.

Her home in space was brightly lit, compact and cheerful. She felt liberated, after the confines of the Lei Feng capsule, within which it had been barely possible to move. Everything was new and clean, even the lavatory section, the drawers full of neatly folded coveralls and underwear. The fans and pumps hummed comfortingly, and there was a smell of freshness — not a natural smell, but like a new carpet, she thought.

She slept in a cupboard, a box little larger than she was. Inside, however, tucked into her sleeping bag with the folding door drawn to, she was secure.

She had brought with her the small brass bell that had accompanied her on her first flight, in Lei Feng Number One — how long ago that seemed! As she prepared for sleep, she watched it drift in stray currents in the circulating air, on its curling length of vermilion ribbon, occasionally ringing. The inscribed face of Mao was intermittently visible, like the Moon hidden by clouds.

During her hundred-day flight, she performed science experiments with her space aquarium.

It looked like a suitcase containing two carousels from a compact disc player; but the walls of the carousels were clear, and murky water was visible within. The aquarium contained one thousand mussel larvae, thirty thousand sea urchin eggs and six thousand starfish embryos. One carousel spun up, imitating the Earth’s gravity, and the other provided a gravity-free environment. The experiment had begun three hours after departing Earth orbit, when Jiang had injected a sperm concentrate into a container full of sea urchin eggs.

She had used a microscope to observe the effects of spaceflight on urchin embryo development. The study was designed to provide insight into the causes and cures of osteoporosis and muscular dystrophy. And she followed the calcium formation of a mussel’s shell, to shed light on the bone depletion suffered by humans in space. The creatures’ unusual swimming and feeding patterns, carefully recorded on video, were studied to provide pointers on how the oceans’ fish populations might better be managed. Jiang also spent much time studying the embryos of starfish. The purpose was to learn how to predict and control early birth defects in humans. The embryo of a starfish, in early stages of development, was remarkably similar to that of a human…

The bioscience program was genuine work. But it was essentially a blind: a misdirection, intended to confuse anyone following her mission suspiciously.

In some senses she was lying, and she felt obscure shame about that: to come all the way out here, fifteen times as far as the Moon was from Earth — an astounding technical feat, especially for a country which a century ago had been an agricultural backwater — and lie!

And yet, she felt, on another level she was telling a greater truth, a truth that transcended the exigencies of her mission.

Earth was not alone. Earth and Moon swam together through a sea of objects, of varying sizes, called NEOs: near-Earth objects, also called Earth-crossing asteroids.

The object of Jiang’s mission was known as NEO 2002OA, discovered in 2002. It was a mountain-sized rock, covered with impact craters and a regolith — a pulverized surface layer — like the Moon’s. It was on a course which would bring it within a million miles of Earth: just four times the distance from Earth to Moon, only some one hundredth of the distance from Earth to sun.