For the first time, she understood what the old guys like Jays had been telling her, all these years. Being an astronaut wasn’t supposed to be a career step. It was about going someplace. I really have come a long way from home, she thought.

It was in this mood that she cornered Arkady, in the descent module, when Henry was asleep.

They didn’t need words. They pulled off each other’s coveralls and underwear, until they were surrounded by a drifting cloud of clothing, like Jane Fonda in Barbarella. Then they found places to anchor themselves, with hands and feet, thrusting their mouths and bellies together.

It wasn’t their first time in zero G. In the Space Station they had usually been driven to hide themselves away in some module or other — sometimes a Soyuz, in fact — to find privacy. Sex in space, they had found, was a matter of engineering ingenuity, of anchoring and leverage points, and of some athletic ability. Both partners had to work at it; it was no use relying on Earth’s sticky gravity to pull you down.

Of course there was the usual problem of fluid imbalance. Arkady’s body fluids had pooled above his waist; he didn’t have the hydraulic surplus down below he was used to. But as usual, she discovered to her pleasure, testosterone overcame microgravity.

And this time it was more delicious than ever for Geena: to float here inside the metal walls of this little egg in space, a hundred thousand miles of vacuum all around her, but with Arkady’s strong warmth inside her, his mouth pressed against hers, like two blobs of the primeval ocean come together here, defying the void—

“Holy cow.”

They broke, swearing. Geena grabbed coveralls out of the air — they turned out to be Arkady’s — and held them before her.

It was Henry, of course; his head protruded out of the descent module’s hatch, upside down, his hair tousled with sleep.

“Oh, God,” Geena said.

Henry shook his head. “The fucking ship was shaking. I thought we had a leak.” He looked from one to the other, as they scrambled into their clothes. “So. The two of you. East meets west; astronaut athletics. Of course. How come I didn’t see it before?”

“Henry, I’m sorry—”

“Do what you want. I’ve no hold over you.” And he ducked back into the orbital module, slamming the hatch behind him.

After that, the silences grew very long. Three people tucked into that confined place couldn’t have got further apart or communicated less, Geena thought; it was like the solution to some geometrical theorem.

Two days and seven hours out, all of two hundred thousand miles from Earth, they went over the hill.

They had climbed past the point of gravitational equilibrium, and entered the Moon’s sphere of influence. Up to now they had been slowing down, like a stone thrown up from the surface of the Earth; but from now on they would accelerate, all the way down to the Moon.

Henry marked the moment, watched as the timer ticked past the nominated mark. Of course he felt nothing, no sense of speed or acceleration; he was inside the same old enclosed submarine, and there was no marker post here, or anywhere else.

But they’d clambered all the way out of Earth’s gravity well. Somehow it didn’t seem right, that such a gigantic milestone should pass unmarked. But it did.

The Soyuz carried a small telescope, of sorts. It was a monocular, designed to be used as part of a sextant, for interplanetary navigation by the stars. Now, Henry used it to study the Moon.

He swept his gaze along the terminator, the line between night and day, and the long shadows there; he could see terraces in the collapsed walls of the bigger craters, as if they were cities designed by some intelligence, walls which curved over the close horizon. And littered over the walls and some of the crater floors, he could see boulders, pinpoints of brightness sending long, needle-fine shadows across the dusty ground.

If the dinosaur killer comet had hit the Moon, it would have left a crater like Copernicus or Tycho, with ejecta rays stretching around a hemisphere.

After a time, he abandoned the telescope, and just looked.

In the window, the Moon was still small, no more than the size of a golf ball held at arm’s length. But he could see craters, with his naked eye: a sight denied to every human who ever lived, before Galileo raised his telescope.

He stared into the Moon’s grey light until his eyes blurred with tears.

They passed through one major crisis.

Henry knew almost nothing of the systems that would take him down to the Moon’s surface, and keep him alive there. There hadn’t been time to explain it all, and Geena suspected he didn’t want to know anyhow, until he had to.

But then he started asking how they were going to carry their nuclear weapon down to the surface.

Geena drifted in front of him. “Henry, we can’t do it. We didn’t design the mission that way. We don’t have any spare carrying capacity. The mass estimates—”

“Then we have to leave some mass behind.”

“Like what? The air? The water? We can’t do it, Henry.”

Arguing was difficult in microgravity. They tended to drift around the cabin, colliding with the walls and each other; it screwed up their body language.

“Then,” he said, “how are we supposed to use the nuke anyhow?”

Arkady said gravely, “The nuke has a small rocket pack which can drop it out of orbit, directly to its target. We can bomb Aristarchus, or any middle-latitude site, but—”

“It’s my fault,” Henry said. “I should have been more open.”

“Yes, you should,” Geena said. “The story of your life, Henry. What the hell do you want, anyhow?”

He hesitated. “Suppose I told you I needed to drop the nuke on the South Pole. How could you do it?”

“It’s impossible,” Geena said. “We don’t have the delta-vee for the orbit change. And if you’re talking about delivering it to the surface, rather than dropping it at orbital speeds—”

“Yes. We might have to use the bunker-buster effect.”

“Again, we don’t have the delta-vee,” Arkady said. And he drifted away, and began a conference, in Russian, with the ground controllers.

“There is no way,” Geena said, irritated. “Henry, this is your fault. This is your damn plan, isn’t it? If you told us up front what was on your mind we could have prepared for it.”

He laughed. “That’s impossible. They wouldn’t have let me out of Edinburgh if I had. I guess I thought there would be more — flexibility. More options.”

“Well,” she said heavily, “you guessed wrong.”

He backed off, troubled.

When Geena tried to sleep, she wasn’t disturbed by the noises of the ship’s equipment, the sensations of zero G. She was used to all that. What got to her now were the flashes inside her closed eyelids: loops and meteorite streaks and starbursts, some of them so bright she felt dazzled. The flashes were caused by cosmic rays, heavy particles which had emanated from some ancient supernova, and had crossed light years to pass through her head.

Even in low Earth orbit you were protected from this shit by the Earth’s arching magnetic field. Not out here. And every time one of those ancient little wasps passed through her, it caused a little more damage to her body’s structure.

Slowly but surely, space was killing her…

“I see the Moon, / The Moon sees me, / God bless the priest / That christened me…”

Henry was whispering, but even so it woke her up. She turned in her sleeping bag, and cold air pushed in at the neck.

Henry was hovering by the wall, holding loosely to a stanchion. He was staring out the window, looking at the Moon.

Arkady was curled into a ball, snoring softly.