“Houston, Ares. I guess what strikes me now is that we humans have spawned at the bottom of a hole. A deep gravitational hole dug into space-time by Earth’s mass. And of all the humans who have ever lived, all the billions of them, only the three of us — Phil, Ralph, and I — have ever climbed to the lip of that hole…”

She was aware of Gershon and Stone exchanging doubtful glances; Stone waved Gershon to be still.

York stared back at the receding Earth. She held up her hand, and covered the Earth-Moon system with her palm. “I’m holding up my hand now, and the whole of human history — including even the voyages to the Moon — are hidden from my view by my palm. We’ll spend another year in space before we see Mars loom close, just as Earth is falling away now. A year in this collection of tin cans, with nothing but the stars and the sun beyond the windows. We know it’s going to be difficult, despite all the training and the preparation. But what’s important is that we’ve come out, over the edge of the gravity hole, and now we’re going to see what lies beyond. We have indeed gone up into night, Houston.”

Stone nodded. He was still looking at her, thinking.

York shivered. Suddenly the Mission Module — drifting through space with its ticks and whirs and smells of food and stale farts — seemed like a little home to her, impossibly fragile, the only island of warmth and light in all that dark night.

After a couple of days of floating around inside the Command Module in their long johns and jumpsuits, Jones, Dana, and Stone started to help each other back into their pressure suits. To go through the Lunar Orbit Insertion burn they were going to have to return to their couches and strap on their canvas harnesses.

They finished up a meal: soup and cheese and spreads on crackers, with a grapefruit-orange mixture to drink. Dana had a plastic bag of pea soup. He would take a spoonful of the soup, tap the handle, and the glob of soup would float off, still holding the shape of the spoon. But when he poked the liquid with a fingertip, surface tension hauled it quickly into a perfect, oscillating sphere. Dana leaned over to suck it into his mouth, a little green marble of pea soup.

Jim Dana found life in microgravity startling, the endless unexpected details enchanting.

Most of it, anyhow.

Before suiting up, Chuck Jones decided to take a dump.

That involved stripping stark naked, and climbing into the storage bay under the three metal-frame couches. Apollo’s waste management system consisted of a collection of plastic bags, with adhesive coatings on the brim, and finger-shaped tubes built into the side. Jones had to dig into the bag with his finger — nothing would fall, after all — and hook his turds down into the bag. And afterward he had to break open a capsule of germicide, drop it into the bag, and knead it all together.

In a moment the sounds and smells of it were filling the cabin.

Dana just sat and endured it. The lousy design of the system was hardly Jones’s fault.

The irony was that the Apollo system had been heavily upgraded in the last few years. Rockwell had stretched the original lunar flight design, making it more robust and reliable, and increasing its capacity; Apollo was mostly used as an orbital ferry craft for taking crews to and from the Skylabs, but even flying solo it was capable of supporting as many as four men for eight days in orbit. Rockwell was even trying to make the Command Module reusable, by providing saltwater protection and modularizing its components — so a module could be cannibalized after splashdown, even if the whole thing couldn’t be flown again.

But some things they hadn’t gotten around to fixing, like the plumbing arrangements.

Dana was finding his first flight in space, with its long string of hassles and discomforts, a surprisingly depressing experience. The contrast between the Zenlike emptiness of cislunar space, and the scrambled human attempts to survive in it, struck him powerfully. And the immaturity of the technology compared to his aviation background was striking.

But we really are at the edge of our capabilities out here. Dad’s right. We’re not really up to this. Not yet. We just aren’t smart enough. Clever monkeys, improvising, making it up as we go along, riding our luck, hauling along our plumbing.

Still, it was one hell of an adventure to tell his son Jake about.

Dana took his turn on trash detail. He collected the food bags, spiked them with pills to dissolve the residue, rolled them up tightly, and stuffed them into a plastic garbage bag. He stashed the garbage in a storage compartment. The compartments had been almost full within a few hours of leaving Earth orbit, and the garbage was dumped regularly into space; Enterprise was heading for the Moon surrounded by a little orbiting cloud of food bags and other trash.

The crew settled down to its pre-LOI checklists. It was all done in an uncharacteristic silence, Dana observed. It wasn’t hard to figure out why. Arguably Lunar Orbit Insertion was the key moment of the mission; on it depended the success of their flight — and, of lesser importance to the career astronaut, the success of Moonlab itself.

And they’d have to perform the burn during the loss-of-signal period, while the craft was around the back of the Moon and shielded from the Earth. So there would be no way the men in Mission Control could help them out.

Since his decision to initiate it, Bert Seger had built up the mission, orchestrating the media coverage carefully. Apollo/Moonlab was going to be a feelgood extravaganza, a return to the Moon, a demonstration of competence: a distraction from the collapse of Saigon, the rocketing cost of fuel, the stagnant economy, inflation… He’d even given way to a write-in campaign by Star Trek fans who wanted Enterprise as the call sign for the ship, the first Apollo to the Moon in four years. It didn’t do any good for the Astronaut Office to protest that they didn’t need a call sign for this mission.

It was all fine PR. But the high profile meant that a failure — and a failure caused by some dumb programming fault — would be very embarrassing.

Apollo shuddered slightly, and solenoids rattled. That was the firing of the reaction control clusters, halting the spacecraft’s slow roll. The stack had been rotating since leaving Earth orbit, to even out the sun’s heat; the crew called it “barbecue mode.”

Stone, in the center of the three frame couches, said suddenly, “Hey. I got the Moon. Right below us.”

Dana looked up from his checklist.

It looked as if streams of oil were descending across the glass of the window to Dana’s right. Dana felt a stab of fear; he couldn’t figure what malfunction could have caused that. Then his eyes refocused, and he realized he was looking at mountains. They slid slowly past the window, lit by the slanting rays of the sun, trailing long black shadows.

The mountains of the Moon. “Oh, Jesus. Look out there.”

“It’s only the fucking Moon,” Jones said. “You’re going to be seeing it for a long time. Come on, get back to your lists. Thousand miles out. Six and a half thousand feet per second… We’ve fifteen minutes until LOS, twenty-three minutes from the LOI burn…”

The sun was hidden behind the orb of the Moon, Dana saw, and the Moon was backlit by the corona, the sun’s outer atmosphere. So there was light all around the Moon, as if the far side were on fire. But Dana could see the shadowed side quite clearly; it swam past the window, illuminated by Earthlight, ghost-pale.

The Moon looked like a ball of glass, its surface cracked and complex, as if starred by buckshot. Tinged pale white, the Moon’s center loomed out at Dana, given substance by the Earthlight’s shading: the Moon was surprisingly three-dimensional, no longer the flat yellow disk he had known from Earth.