York had put that stuff aside. Even at the age of sixteen, York was hot on science, on the strictness and logic of it; she found herself getting unreasonably impatient at illogic, and wishful thinking, and the emotional coloration of rational processes of all sorts.

(Actually she was much too severe for most of the boys her mother tried to match her with. You’d think that someone who’d suffered as messy a divorce as Maisie York would learn not to meddle in other people’s relationships…)

The fact was that to her the real Mars was a hell of a lot more interesting than Lowell’s anthropocentric dreams.

Because of Mariner, Mars had turned into a place you could do some geology.

How would the geology of Mars differ from Earth’s? What would that tell you about Earth that you couldn’t have learned from staying at home? A hell of a lot, probably.

Mariner’s thirteenth frame had electrified her.

The thirteenth picture showed craters with frost inside them.

My God. Not the Moon, not Arizona. Mars is something else. Something unique.

Ben eyed York, interested, speculative. “So you’re a closet Mars nut. I ought to take you out to JPL sometime. That’s where they run the planetary probes from… Hey, Natalie. Maybe you ought to apply.”

“What for?”

“The astronaut corps.”

“Me? Are you joking?”

“Why not? You’re qualified. And we need people like you. Even Spiro says so; he thinks people were turned off by Apollo because it was too engineering-oriented.”

“Well, so it was.”

Priest eyed her. “I’m serious, actually, Natalie. It’s a genuine opportunity for you. You could go work for Jorge Romero’s geology boys in Flagstaff, and train the moonwalkers. That’s how Jack Schmitt got into the program, and they say he’ll make it to the Moon.”

“You worry me, Ben. How can a crazy man like you be allowed to drive a car at night?”

“Here.” Driving with one hand, he reached up, turned back his lapel, and unclipped a silver pin, in the shape of a shooting star trailing a comet’s tail.

“What is it?”

“My rookie’s pin. Someday soon I’m going to get a flight. So you need this more than I do. Take it. And when you’re the first human on Mars, when the Spiro Agnew lands in 1982, drop it into the deepest damn crater you see, and think of me.”

“You’re crazy,” she said again. “You should give it to Petey.”

They fell silent.

Her thoughts turned back to Jackass Flats.

They don’t even contain the vented hydrogen. And Mike never thought to tell me about any of this. Why? Because he thought I couldn’t stand to hear it? Or because he can’t even see what’s wrong here?

What does that say about us? And — do we really have to do this shit to get to Mars?

She closed her fingers around the little pin Ben had given her.

Ahead of them, the interstate was a band shining in the starlight and stretching toward the glow of Vegas.

Major Philip Stone joined the USAF in 1953, at the age of twenty. He arrived in Korea in time to make a series of hazardous sorties. Well, Korea had been a turkey shoot. But Stone hadn’t enjoyed combat. His buddies called him too serious — a straight arrow. But for Stone, the important thing was what he could learn in each flight, either about his machines or about himself.

After the war, his disciplined curiosity found a new focus.

In the early 1960s the most promising route to space, if you were inside the USAF, had looked like the experimental high-altitude rocket aircraft program. The X-15s could even give their pilots astronaut wings, by flying through the officially recognized lower limit of “space,” at fifty miles high. The X-15s were to lead to the advanced X-20 — the Dyna-Soar — in which a guy would have been boosted into orbit, and then he would have flown back down, landing like an airplane.

But with men routinely being hurled into space in ballistic capsules like Mercury and Gemini, the X-20 looked too advanced for its time, and it soon ran up a bill as large as that for the entire Mercury program without delivering a single flight article. And it was canned.

Now, the only way for a pilot to reach space was to transfer to NASA. Neil Armstrong was another X-15 pilot who had gone that way before. And so that was what Stone had determined to do.

But first he had some unfinished business.

In 1969, Stone was thirty-seven years old.

“Drop minus one minute.”

“One minute,” Stone said. “Rog. Data on. Emergency battery on. I’m ready when you are, buddy. Master arm is on, system arm light is on…”

The B-52 reached its launch station over Delamar Dry Lake in Nevada. The rocket plane was suspended from the bomber’s wing pylon like a slim, black, stub-winged missile, crammed full of liquid oxygen and anhydrous ammonia, ready for its midair launch.

Stone was sealed up inside the X-15. The B-52’s engine was just feet away from his head, but Stone, cocooned inside the pressurized cockpit, could barely hear its noise. From the corner of his eye he could see the chase planes clustered close to the B-52. At last, this damn flight is going to be over and done with.

After fifteen years, the X-15 program was winding up. There was only one serviceable ship left: X-15-1, the first to fly back in 1960, a veteran of seventy-nine previous missions. The Edwards people wanted to finish up the program with one last flight, the two hundredth overall; and they had asked Phil Stone to stay around long enough for that. But then there was a series of delays and technical hitches, and the winter weather had closed in, until the flight was all but a year later than it had originally been planned for.

For Stone that was a year out of his life wasted. But he’d spent the time preparing for his move to NASA, trying to be sure he started off his new career as well placed as he could be.

“Fifteen-second mark to separation. Chase planes on target. Ten seconds.”

He felt his heart, somewhere under the silver surface of his pressure suit, pumping a little harder. As it was supposed to at such moments.

“Three. Two. One. Sep.”

With a solid crack the B-52’s shackle released the X-15, and the plane dropped away from its mother, and Stone was jolted up out of his seat.

Stone emerged from the shadow of the bomber’s wing, at forty-five thousand feet, into a shock of brilliant sunshine. He was already so high that the morning light was electric blue, more like dusk. The chase planes were little points of silver light around him, with their contrails looping through the air.

The land curved below the plane’s nose, as if the Mojave was some huge, smooth dome. He could see the worn hump of Soledad, the Lonely Mountain, brooding over Rogers Dry Lake, half a mile above sea level. Everywhere the dried-up salt lakes glistened like glass, speckled with gray-green sagebrush and the twisted forms of Joshua trees. It was a flat, desolate, forbidding place. But every summer the desert sun baked the damp lake beds to a flat and smooth surface. The whole place was like one huge runway, and you could land anywhere in reasonable safety.

It was a little after ten-thirty in the morning.

Stone pushed the button to ignite the X-15’s rocket engine.

He was kicked in the back, hard. The plane’s nose was tipped up into the sky as ammonia and oxygen burned behind him, and he rode higher into the deepening blue. He could hear his own breathing inside his helmet; otherwise, there was barely a sound — he was outpacing the noise and exhaust plumes behind him.

Far ahead he saw a speck of light, like a low star. It was a high chase plane. It grew out of nowhere in a flash, and plummeted backwards past Stone, as if it were standing still.

At forty thousand feet he reached .9 Mach, and he could feel a bumping, like a light airplane flying in turbulence. He was moving so quickly that the air molecules couldn’t get out of the way of his craft in time.