“Okay, Ralph,” Stone said. “Translation control power, on.”

“On.”

“Rotational hand controller number two, armed.”

“Armed.”

“Okay. Stand by for the primary TVC check.”

“Pressures coming up nicely,” Gershon said. “Everything is great…”

A hundred feet behind them, the big MS-II injection stage was rousing from its long, interplanetary hibernation. Heaters in the big cryogenic tanks were boiling off vapor, bringing up a pressure sufficient to force propellant and oxidizer out of the tanks, and Stone and Gershon were running tests of the sequence which would bring the hydrogen and oxygen into explosive combination inside the combustion chambers of the four J-2S engines.

In the window above her, she could see a segment of a circle: bone white in the starlight, quite precise, immense.

“…Oh, my God.”

Stone twisted, awkward in his suit, and peered over his shoulder. “What’s wrong?”

“Look at that. I think it’s Hellas.” The deepest impact crater on Mars. And white, with its frozen lake of carbon dioxide. Somewhere in there, the Soviets had set down Mars 9.

Stone grunted. “You’re going to be looking at that for a long time.” He turned his back, his disapproval evident, and resumed the preburn checklist with Gershon.

“Thirty seconds,” Stone said. “Everything is looking nominal. Still go for MOI.”

He placed his gloved hand over the big plastic firing button.

The whole burn was automated, York knew, controlled by computers in the cluster’s Instrumentation Unit, the big doughnut of electronics behind the Mission Module. Multiple computers, endlessly checking everything and backing each other up and taking polls among themselves. It was hard to see what could go wrong. Nevertheless, Stone sat there with his hand on the button, ready to take over if he had to. To York, it looked comical — and yet, somehow heroic as well. Touching.

“Twenty seconds,” Stone said. “Brace, guys.”

“All systems are go for MOI,” Gershon said.

York checked her own racks. “Roger, go.”

She checked the restraints across her chest, rapidly, and settled her head against her canvas headrest. She tried to make sure there were no creases or folds in the thick layers of the pressure suit under her legs or back.

She felt her heart pound, and chill sweat broke out across her cheeks and under her chin.

“T minus ten seconds,” Gershon said.

Stone’s hands hovered over his controls.

“Eight seconds.”

“I got a 99,” Stone said. He pushed a button. “Press to proceed.”

York felt air rush out of her in a sigh.

“Six seconds,” Gershon said. “Five, four. Ullage.”

There was a brief rattle, a sharp kick in the small of her back. Eight small solid-fuel rockets, clustered around the base of the MS-II, had given the booster a small shove, helping the propellants settle in their tanks.

Gershon said, “Two. One. Ignition.”

The crisp ullage shove died, to be replaced by a smooth, steady push that she felt in her back, her neck, her thighs.