Stone said, “Try cycling the landing radar breaker.”

Gershon pulled out the radar’s circuit breaker, his muscles tense with anger, and shoved it back in its slot. “Okay, it’s cycled.”

The caution lights continued to show. No lock.

He turned to look Stone in the eye. “Fine day for a landing.”

He meant: Fuck the rules. Fuck the radar. Fuck Houston; they’re so far away we’ll be on the surface by the time they know what’s going down. We’ve come too far to quit now. I say we go for a landing, by eye if we have to. Fuck it.

Stone stared back at him.

Damn it, you cold bastard. What are you going to do?

Gershon could feel the cabin tip up around him; beyond his big window, sky and a fine edge of red landscape slid past. Challenger was beginning to pitch up, as it dropped closer to the ground.

“Twenty-four thousand feet,” Stone said. “Coming up to throttle down. Mark.”

The primary guidance program would take the descent engine down to 60 percent thrust. Gershon could feel the thin vibration subsiding smoothly. Right on schedule. “That felt good,” he said. “Better than the sims.”

“Twenty-one thousand. We’re still go. Apart from the radar lock. Velocity down to twelve hundred feet per second.”

Twelve hundred. Aircraft speed. Gershon took hold of his controls. I’m flying in the atmosphere of Mars. He looked out of his window. The stars were all washed-out, and the sky was a tall dome of brown light. And he could see the ground. It was a rumpled landscape that slid underneath him. Visibility was good: the contrast, the shadows cast by the low morning sun, made everything stand out.

Challenger was approaching the landing site in a broad sweep from the southwest, so it was flying over the ancient, cratered terrain of the southern hemisphere. It was almost like a lunar landing sim, with craters piled on craters, some so old and huge they were almost obliterated by newer strikes. But these craters had sand dunes rippling across their floors, and there was one big old fellow whose walls looked like they had collapsed under a stream of running water. The Moon, it ain’t.

The landscape was desolate, curving tightly, forbidding. It was an empty planet, no ground support… No runway lights down there, boy. On the other hand, nobody shooting at your ass, either.

“Seven minutes thirty,” Stone said. “Sixteen and a half thou. Coming up on high gate. Still no lock.”

“High gate” was the point in the trajectory where Gershon should be able to see his landing site for the first time. He peered ahead.

The designated landing site was just to the north of an escarpment at the mouth of an outflow valley. The valley, according to York’s descriptions, would look like a dry riverbed. Gershon had studied the site from orbiter photographs and plaster-of-paris models until he knew it like he knew his own apartment.

But coming in now, with the sun low, and the ship still tipped up at more than fifty degrees, and the light glinting off his little triangle of a porthole…

Nothing looked like it was supposed to. The land was complex, tortured, its nature changing rapidly. Every shadow was deep and black, and the ocher-colored surface features seemed to leap out toward him, the vertical scale magnified by the contrast.

“Fifteen thousand,” Stone said. “Still no lock.”

Shit.

“Okay, Ralph, let’s go over the abort procedure.” Stone sounded resigned.

Goddamn it to hell, he’s given up.

“We pitch over, activate the ascent program… countdown to mission abort starts at eight thousand feet—”

“No. Don’t abort,” Natalie York said suddenly.

Stone looked at her. “Huh?”

“Don’t abort. We may be flying over a radar-dark area.”

“And what,” asked Stone drily, “is a radar-dark area?”

“Volcanic ash,” she said. “Pumice.” She was straining in her harness, trying to see the battered landscape out of their pilots’ windows. “Low-density stuff; not many rocks. It reflects radar badly. There’s nothing for the landing radar to lock on to.”

“Or maybe,” Stone said, “the landing radar is screwed.”

“Don’t abort.”

Stone and Gershon exchanged looks.

“Nine thousand,” Stone said. “Still no lock.”

They’d already busted the mission rules, Gershon realized.

Stone said, “Ralph—”

And then the warning lights went out. The radar lock had come in.

York gasped, an explosion of relief.

“Jesus.” Gershon slammed his fist into his control station. “We is fucking go.”

“We is indeed,” Stone said tightly.

Gershon twisted over his shoulder to look at York. “I guess we flew right on over all that pumice stone, huh.”

She stared back at him. “I guess.”

He had no idea if she’d just been bullshitting, he realized, about the pumice stone. He didn’t think York was the type to do that, but it was possible. And he also didn’t know if Stone would really have pulled the plug, or let him go on and try to land without the radar.

He didn’t, he realized, know his crewmates as well as he thought he did.

“Eight thousand,” Stone rattled off. “Down velocity one hundred feet per second. We’re go for the landing.”

“Rager.”

Gershon took hold of his controls. He had an attitude control adjuster in his right hand — a joystick with a bright red pistol grip — and on his left there was a toggle switch called the thrust translator controller, which would squirt the down-pointing reaction thrusters to reduce the rate of fall. It was all linked up by the electronics to the reaction control subsystem, which would do most of the steering for him.

He pulsed the reaction control thrusters; solenoids rattled comfortingly.

He handed control back to the computer. “Manual auto attitude control is good.” He felt a surge of renewed confidence. The radar was locked in, and the thrusters were copacetic. When the time came, when he had to take control of the ship for the final landing, he knew that everything would be fine.

“Seven thou,” Stone said. “Here we go. High gate. Right through that gate.”

Under computer control, Challenger tipped up a little more, tilting Gershon forward. He stared ahead. Speeding over the close horizon, they were coming to what looked like an escarpment, a ridge marking out the edge of the cratered terrain. Beyond that ridge, the land looked different: smoothed over, lacking craters, kind of like mud, like a flood plain…

And there was a valley under his prow, snaking north from out of the southern plateau. It looked like a gouge in a woodcut, with a big wide crater just to the northeast.

It looked just like the maps and the models in the back rooms at JSC.

Gershon crowed. “I’ve got it! I have Mangala! Just as fat as a goose.”

He grasped the controls of Challenger, ready to land.

The MEM was standing on its rockets, drifting over the landscape, like an ICBM trying to land on its tail.

“Three thousand feet. Seventy feet per second. Everything’s go,” Stone said. “Go for landing. We’re go, hang tight. Two thousand. Windspeed ten feet per second.”

Windspeed. Another hazard they didn’t face on Apollo. But 10 fps was low enough not to matter.

“Give me an LPD,” he told Stone.

“Forty-three.”

He looked through his window, sighting along the forty-three-degree reticle, his current Landing Point Designator. He sensed invisible polynomial curves reaching out, in the computer’s imagination, to join him to his landing site, like a smooth glass highway across the Martian air. None of those damned higher-order wiggles this time. Even though it shared the clunky human interface of other Apollo-based systems, the hardware and software was an order of magnitude more powerful than the antiquated shit he’d had to fly on the MLTV.

Now he could see the site where the computer was flying him, more than a mile away, closing in fast, in line with the reticle…