To assemble this much mass in Earth orbit had taken all of nine Saturn VB flights over the last five years — half of them manned. The booster stages and their tanks had been flown up and assembled more or less empty, and then pumped full of gas from tanker modules. The cluster was an exercise in enhanced Apollo-Saturn technology, of course, and the essence of its design went all the way back to the 1960s. But NASA had had to develop a raft of new techniques to achieve it: the assembly in orbit of heavy components, the long-term storage of supercold fuels, in-orbit fueling.

Sailing over the Earth, brilliantly lit by the unimpeded sunlight, the booster stack was complex, massive, new-looking, perfect, like a huge, jeweled model. Once they’d docked, she wouldn’t see the cluster from outside again like this for a year. Not until, she realized with a jolt, she receded from it in the MEM, in orbit around Mars.

Stone stretched, raising his arms above his head and reverse-arching his back, so that he floated up out of his frame couch. His long limbs unfolded with evident relief; he really did look too tall to be an astronaut, York thought.

He said, “It’s been a long day already. What say we have ourselves some lunch before we proceed with the docking? If you can take it, Natalie.”

Food? Now? “Sure,” she said. “I’m fine.”

“Rager,” said Gershon. He climbed out of his couch. He moved in microgravity as if he’d been born to it; he just floated up out of his couch, pushed at the instrument panel in front of him, and went swimming around like an eel.

He rooted in the equipment bay beneath the couches. He got to the food locker and lifted the lid; it was full to bursting with little cellophane packets of food, all Velcroed in place.

Once they got into the Mission Module, the standard of cuisine would improve, York knew. But while they were stuck inside the Apollo they had to make do with squirting water into color-coded plastic bags of dehydrated food. Still, she wasn’t about to complain. The Command Module was like a cute little mobile home, with its warm water for food and coffee, and toothpaste, even a system for the guys to shave.

Gershon came floating up with a handful of gold-painted bags. “Hey. I found these at the front. None of us is coded gold, are we?”

Stone smiled. “Nope. I had those put there for you to find.”

York studied the bags. “Beef and potatoes. Butterscotch pudding. Brownies. Grape punch.” She looked at Stone. “What’s this? None of this was in my personal preference. In fact, I hate butterscotch pudding.”

“I thought it was kind of appropriate. This was the first meal the Apollo 11 crew ate in space. Straight after translunar injection, after they left Earth orbit for the Moon.”

“All right,” Ralph Gershon said, and he pulled a hose out of the potable water tank and squirted the spigot into his bags with enthusiasm.

York looked at the bags again. Butterscotch pudding, in memoriam. Bizarre.

But maybe, after all, it was appropriate.

Chuck Jones snapped his visor closed and tugged at the umbilicals on his pressure suit, testing their fittings.

He stepped to the edge of the tank. It was a big blue rectangle, like a swimming pool. T-shirted divers were already moving through the water, playing around the sim like dolphins; cables trailed through the water, around the blocky white shape of the sim itself.

It’s like a fucking kid’s game, Jones thought. Sims. How I hate sims.

He turned to see his partner, Adam Bleeker. Because his suit was so stiff, Tones had to hop around like a rabbit. “You okay, kid?”

Bleeker seemed to start. “Sure. Yeah, sure, Chuck.”

Jones snickered to himself. He knew he could put a bug up the ass of a raw kid like Bleeker, just by smiling at him. “Good boy. Welcome to the Weightless Environment Training Facility, here in sunny Texas. Beautiful sight, isn’t it?”

Bleeker turned to the water. “I think I’ve got a kind of Monday-morning feeling about this, Chuck.”

“So do I, Adam; so do I. I hate this fucking fish tank. But we gotta go through with crap like this, or they won’t let us fly their beautiful birds. You all set?”

“Let’s do it.”

His breath loud in his ears, Jones stepped onto the white platform before him. He was suspended over the pool. With a whine of hydraulics, the platform lowered his clumsy, umbilicaled bulk into the water.

The divers loaded him up with weights that would neutralize his buoyancy, and so simulate weightlessness. Then they got hold of Jones’s suited arms, and began to drag him through the water toward the sim. The water was hot, for the benefit of the divers.

The WET-F, pronounced “wet-eff,” was one of the largest simulator facilities there at MSC. The pool was set at the center of Building 29, a big circular building that had once served as a centrifuge. A sleek ambulance stood beside the pool, and there was a decompression chamber nearby. Big clunky white pieces of kit, simulators for other exercises, stood beside the water; cranes running along the roof would lower them in when required.

Jones hated the WET-F. He could never forget the presence of the water around him: the resistance to every movement, the clammy light, the glopping of bubbles, the shadowy forms of the divers.

Conditions more different from the ice-cold stillness of space it was hard to dream up.

Looming ahead in the water he could see the sixty-foot-long hulk of a mocked-up S-IVB, a Saturn third stage, with the mouth of its single engine bell gaping at him. The Multiple Docking Adapter was a squat cylinder fixed to the front of the S-IVB, and a crude, open-ended mock-up of a docked Apollo Command Module was fixed to the front of that.

The idea was that the empty S-IVB would be used as a space station shell, a Skylab, once it had reached orbit. The S-IVB and the Apollo carrying its crew would be launched separately, by Saturn IB boosters, the smaller, cheaper cousins of Saturn Vs. The astronauts would dock with the booster by nuzzling the nose of their Apollo against the docking adapter, and then enter through specially fitted airlocks. The crew would clean out the shell and settle down to live inside the big liquid hydrogen tank.

The sim wasn’t painted, or finished in any way. It all looked ungainly, ugly, evidently lashed up in haste.

The simulation supervisor’s voice sounded in his headset. “Good morning, Chuck, Adam.”

Good morning to you, asshole.

Bleeker turned and waved at one of the ubiquitous TV cameras.

The SimSup said, “I just want to review the basic parameters of the sim with you, before you start. Now, you know this isn’t an integrated sim.” Meaning they weren’t hooked up to Mission Control. “This is just a preliminary trial of the checklist we’re going to have to use when we fit out the workshop in orbit. Okay, let’s proceed.”

The divers nodded to Jones, and they guided him closer to the Apollo mockup. It was just an open cone, fitted to the docking adapter. The simulation was supposed to start at the moment at which the crew was moving into the workshop to configure it for habitation.

Their first job was to dismantle the docking assembly in Apollo’s nose and open up the tunnel to the workshop. That part, at least, should go smoothly, because that sort of docking was standard operating procedure on the Moon missions.

Jones heard Bleeker’s breath scratching as he hauled at the heavy docking-probe assembly. “Take it easy, kid. We’re being paid by the hour.”

Bleeker laughed, and his posture relaxed a little.

When they had the probe assembly loose, Bleeker passed it to a diver.

Bleeker moved ahead of Jones into the Multiple Docking Adapter. The adapter was a tight tunnel, lined with lockers. All the equipment for living quarters, clothes, food, experiments, and the rest was stored in the lockers during the launch; after they’d fitted out the hydrogen tank for habitation, Jones and Bleeker would have to return here, unpack the lockers, and move the equipment into the tank.