Reliability was essential on long-duration missions. Many of Apollo’s systems had redundant backups — straightforward copies, to be substituted in case of a failure — but the old triple-redundancy design paradigm they’d used to get to the Moon wouldn’t work, it had been found, on long-duration missions. Enough redundancy to achieve an acceptably low level of risk over such a span of time would have resulted in a spacecraft of immense weight and complexity.

So the designers had gotten smarter. In addition to simple redundancy, some functions could be performed by dissimilar components, or by components from different subsystems, to reduce the chance of a single failure mode knocking out many functions altogether — as had happened in Apollo 13. And the maintenance capabilities of the crew weren’t ignored, either. The whole ship was more modular and accessible than in its first design, so that components could be reached, and repaired or replaced comparatively easily. There were also isolation valves, switches, test equipment, and fault diagnosis tools. Some of the components contained their own BITEs, microelectronic built-in self-test units.

Hauling an Apollo all the way to Mars also provided some abort options. On return to Earth the Apollo, with the Mission Module, was due to be inserted into a highly elliptical orbit around the planet: two hundred by a hundred thousand miles, a swooping curve that would take the stack halfway out to the Moon and back, an orbit accessible to Ares at a relatively low expenditure of fuel. The Command Module would be able to take them down to the surface of Earth from such a trajectory; the reentry heating would be less than a return from the Moon. And if Apollo were to fail, the crew could survive in its high orbit until rescue came, in the form of another five-man stretched Apollo.

If they couldn’t make Earth orbit at all — for instance if the J-2S, the single engine of the final MS-IVB booster stage, were to fail — they could attempt a direct entry from the interplanetary coast. The heat shield on the Command Module’s underside had been thickened and toughened up, so that it would at least give them a fighting chance of surviving a direct reentry into Earth’s atmosphere. The velocity would only be around 15 percent faster than a lunar return.

And, if the Mission Module’s life support were to fail in-flight, it would even be possible for the crew to retreat to the Command Module and use it as a shelter. A lifeboat. Just then, with Gershon alone in it, the Command Module seemed pretty roomy; it wasn’t like that with three of them aboard, and things would be pretty tough if they had to spend weeks, or even months, cooped up in there.

But it was better than dying.

Every aspect of the mission had been designed with failures in mind, to give options at every point, to leave no “dead zones” where there was no abort capability. The designers had almost succeeded.

Gershon hummed along with Mozart as he worked.

This fifty-day checkup was a chore, of course, but everything on the fucking flight was a chore for Gershon. And it was the same on every long-duration spaceflight.

Gershon’s moment was going to come when he took that MEM down through the thin air of Mars itself. But he’d basically be working at peak effectiveness for, what? — forty, fifty minutes? — out of a flight that was going to last a year and a half. Not much of a payload ratio, Ralph. But that was okay. It was a bargain that Gershon was prepared to accept. Because there he was, on an odyssey to Mars.

The first time he’d come across the name “Ares” had been in a battered old book he’d picked up from a dime store in Mason. It was a collection of science-fiction stories, by someone called Stanley Weinbaum. The title story was “A Martian Odyssey,” and it featured a ship called Ares and four men exploring the surface of an exotic, mysterious Mars. Weinbaum’s magical words were alive in his memory, still, after all those years; it was as if he could feel the stiff, yellowing pages of that battered old paperback in his hands.

When he’d heard they were going to use Weinbaum’s name for the mission, Gershon had whooped.

He’d worked his way through the science-fiction canon as he grew older, and he’d ridden many other ships to Mars. Bradbury had been elusive, with his hinting descriptions of silver locusts — pulsing with fire, swarming with men — falling to the surface of a beautiful, inhabited planet. Clarke’s Ares, on the other hand, had been described in great detail. It was a dumbbell shape of two huge spheres, separated by a hundred yards of tubeway. The rear contained atomic motors — serviced by AEC robots — and the leading sphere was living quarters, with cabins and a huge dining room and an observation gallery…

Sitting in the canvas frame couch, Gershon sucked some more juice out of his tube and ran his hand over the surface of the grimy instrument panel before him. He grinned. Dining rooms, huh.

Gershon thought of Apollo technology the way, he supposed, other guys might think of classic cars. Like a Corvette, maybe. Apollo was a beautiful machine, and it worked, and it had achieved great things. And even after all those years it was still better than anything the Russians could put up…

And it seemed entirely appropriate to him that the first mission to Mars — for real — should be conducted not in some lost von Braun-type dream of the 1950s, but in a handful of strung-together Apollo-application cans.

Still, he knew that this voyage was a fulfillment of more dreams than just his own. As Ares followed its long, spiraling trajectory to Mars, he felt that it wasn’t alone: it was accompanied by a fleet of ghostly ships, huge silver forms, from the pages of Clarke and Heinlein and Asimov and Bradbury and Burroughs…

The Mozart floated around the cabin, and Gershon worked patiently through his checklist.

Rolf Donnelly swung his car into his space outside Building 30, the Mission Control Center. He got out, whistling.

There was a new sign up, in a parking space close to the building: MCC M O EMPLOYEE OF THE MONTH. Donnelly laughed. Welcome to government work! You’re in Mission Control, and your prize for a good job well-done is the loan of a parking space!

He took a breath of the muggy autumn air. It would be his last fresh air for a while; one of the few things he didn’t like about working in Building 30 was that it was completely enclosed. He walked slowly by the big air-conditioning grilles on the outside of the building; in the spring, birds nested in there, but he couldn’t see any activity.

Donnelly was still whistling as he turned into the building. He was a flight director, and he was going to be lead flight for the Apollo-N mission. And he loved his job.

The big display screens at the front of the room bore spectacular images from Kennedy, of climbing metal, billowing smoke, flames as bright as the sun.

The Saturn VN lifted smoothly off the pad.

A few seconds into the Apollo-N flight, the Mission Operations Control Room was an amphitheater of calm, of control, of patient work. From his position in the command and control row of the MOCR, third from the front, Donnelly could see everything: the rows of blocky benches, the workstations with their clumsy old CRTs and keyboards bolted into place, manned by the controllers that made up his flight team. Indigo Team. The workstations were littered with ring binders of mission rules, polystyrene coffee cups, yellow notepads.

On the brown-painted walls there were mission patches, dating all the way back to Gemini 4; and there were plaques, framed in the team colors of retired flight directors. There was a big Stars and Stripes at the front of the room. The light was low, the colors gloomy; but the CRTs glowed brightly.