As they approached the ridge, the rim of Voltaire disappeared under the black curved horizon. Dust blew away from the ridge as the plane’s rockets shot exhaust over it. There was only a few centimeters of dust covering the bedrock. Carbonaceous chondrite, five billion years old. They docked with a hard thump, bounced away, slowly drifted down again. He could feel the pull toward the floor of the plane, but it was very slight. Probably he didn’t weigh more than a couple of kilograms, if that.
Other rockets began to land on the ridge to either side of them, kicking clouds of dust into the vacuum, where they drifted slowly down. All the planes bounced on impact, then came down gently through their dustclouds. Within half an hour there were eight planes lined up on the ridge, running along it to the tight horizons in both directions. Together they made a weird sight, the intermetallic compounds of their rounded surfaces gleaming like chitin under the surgical glare of unfiltered sunlight, the clarity of the vacuum making all their edges overfocused. Dreamlike.
Each plane carried a component of the system. Robot drillers and tunnelers and stamps. Water-collection galleries, there to melt the veins of ice in Deimos. A processing plant to separate out heavy water, about one part in 6,000 of the ordinary water. Another plant to process deuterium from the heavy water. A small tokamak, to be powered by a deuterium-deuterium fusion reaction. Lastly guidance jets, though most of these were in planes that had landed on the other sides of the moon.
The Bogdanovist technicians who had come up with the equipment were doing most of the installation. Sax got suited up in one of the bulky pressure suits on board, and went out the lock and onto the surface, thinking to look and see if the plane carrying the guidance jet for the Swift-Voltaire region had landed.
The big heated boots were weighted, and he was glad of it; escape velocity was no more than twenty-five kilometers an hour, meaning that with a running start one could jump right off the moon. It was quite difficult to keep his balance. Millions of tiny motions carried one along. Every step kicked up a healthy cloud of black dust, which slowly fell to the ground. There were rocks scattered on top of the dust, usually in little pockets they had made on landing. Ejecta which had no doubt circled the moonlet many times after ejection, before dropping in again. He picked up one rock like a black baseball. Throw it at the right speed, turn around, wait for it to go around the world, catch it chest high. Out at first. A new sport.
The horizon was only a few hundred meters away, and it changed markedly with every step— crater rims, spallation ridges, and boulders popping up over the dusty edge as he trudged toward it. People back on the ridge, between the planes, already stood at a different upright than he did, and were tilted away from him. Like the Little Prince. The clarity was starting. His footprints made a deep trail through the dust. The dustclouds hanging over the footprints got lower the farther back they were, until they settled, four or five steps back.
Peter came out of the lock and walked in his direction, and Jackie followed. Peter was the only man Sax had ever seen Jackie really attracted to, in that intense helpless manner of the orbiting object, the lovelorn, yearning for orbital decay. Peter was also the only man Sax had ever seen who did not respond to Jackie’s amorous attentions in any way. The perversity of the heart. As in his attraction to Phyllis, a woman he had not liked. Or as in his desire for the approval of Ann, a woman who had not liked him. A woman with crazy views. But perhaps there was a rationality to it. If someone moons over you, you have to wonder at their judgment. Something like that.
Now Jackie trailed Peter like a dog, and though their faceplates were a copper color, Sax could tell just by her movements that she was talking to him, cajoling him somehow. Sax turned to the common band and came in on their conversation.
“— why they’re named Swift and Voltaire,” Jackie said.
“Both of them predicted the existence of the Martian moons,” Peter said, “in books they wrote a century before the moons were seen. In Gulliver’s Travels Swift even gives their distances from the planet and their orbit times, and he wasn’t that far off.”
“You’re kidding!”
“No.”
“How in the world did he do that?”
“I don’t know. Blind luck, I guess.”
Sax cleared his throat. “Sequence.”
“What?” they said.
“Venus had no moon, Earth one, Jupiter four. Mars should have had two. Since they couldn’t see them, they were probably small. And close. Therefore fast.”
Peter laughed. “Swift must have been a smart man.”
“Or his source. But it was still blind luck. The sequence being a coincidence.”