Rolf Donnelly went around the horn, one last time.

“Got us locked up there, INCO?”

“That’s affirm, Flight.”

“How about you, Control?”

“We look good.”

“Guidance, you happy?”

“Go with systems.”

“FIDO, how about you?”

“We’re go. The trajectory’s a little low, Flight, but no problem.”

“Booster?”

“Everything’s nominal for the burn, Flight,” Mike Conlig said.

“Rog. Capcom, how’s the crew?”

Natalie York was on capcom duty again. “Apollo-N, Houston, are you go?”

“That’s affirmative, Houston,” Chuck Jones replied briskly on the air-to-ground loop.

“Rog,” Donnelly said. “Okay, all controllers, we are go. Thirty seconds to ignition.”

York said, “Apollo-N, you are go for the burn.”

Apollo-N was drifting over the darkened Pacific; Ben Priest could see a bowl of white light in the waters below — the reflection of the Moon — and, all but lost in that milky vastness, the lights of a ship.

The crew lay side by side in their couches, cocooned in their pressure suits once more. Priest felt his heart pumping harder. We’ve done everything we can to check this damn bird out; now we have to go full bore on it, and that’s all there is to it.

At ten seconds the DSKY threw up a flashing “99.” Chuck Jones reached out and pushed PROCEED.

Through the changing numbers on his console, Mike Conlig watched as NERVA’s nuclear core was brought back up to its working temperature. Liquid hydrogen was already gushing out of the big S-NB tank and pumping into the cladding of pressure shell and engine bell, and, Conlig knew, would be reaching the radioactive core about now, where it would be flashed to vapor as hot as the surface of a star.

The core temperature began to climb, following the curve laid out in the manuals -

No, it didn’t. The rise was too fast.

Conlig watched with dismay as his numbers drifted away from nominal.

As NERVA lit, the spacecraft shuddered.

Priest was pushed back into his seat with a long, gentle pressure. Perfect. Just like the sims.

Natalie York called up, “You’re looking good here. We’re hawkeyeing your trajectory. You’re right down the center line.”

Priest’s job was to watch the pressure and temperature readouts from the S-NB stage, the NERVA engine, and its big hydrogen tank. Jones was monitoring the attitude indicator with its artificial horizon, ready to take over the steering if the automated systems failed. Dana was calling out their increasing velocity from the DSKY readout. “Thirty thousand feet per second… thirty-three…”

Mike Conlig was aware of a deadly dryness in his mouth. On the loop from the back room, someone was screaming in his ear.

The numbers, white on a green screen, filled his world.