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…

Shit.