"I remember you talking about mat last time I was up here," Rhee said. "That's one of the reasons I picked that topic. I thought it might help you."

"It'd be a terrific help, Bianca. When we actually start the project, you could be part of our team."

She beamed at him.

"If we ever start it," he added, more soberly.

"If?"

"I'm learning economics the hard way," Doug said. "I want to get an asteroid and mine it so we can use nanomachines to build Clipperships from asteroid carbon, make them out of pure diamond."

"Diamond?"

Nodding eagerly, Doug said, "Diamond's got a strength-to-density ratio fifty times better than the aluminum alloys we make at the space stations."

"And nanobugs can produce pure diamond?"

"Out of the carbon we mine from the asteroid, sure: atom by atom."

"Wow!" Rhee said. "That's brutal!"

"But it takes money to get started. Capital investment And Moonbase isn't making enough profits to swing it"

"Won't the corporation-"

Doug interrupted, "The board of directors won't sink any risk capital into Moonbase, not with the U.N. working up an international treaty that'll ban nanotechnology completely."

"That would shut Moonbase down!" Rhee said, alarmed.

"Maybe," Doug replied. "But whether it does or not, the corporation isn't going to provide the capital we need for the asteroid project."

Rhee stared glumly at her half-finished drink. "And I was ready to come up here full time."

"Full time? Really?" Doug asked. "I mean, I know you've got family and school and everything back Earthside."

"There aren't that many jobs for astronomers back there," she said. "I couldn't even get a teaching assistant's position this semester."

"Well, I'm sure we could fit you in here." Then he added, "If this flipping nanotech treaty doesn't shut us down completely."

"You don't think that could happen, do you?"

Doug smiled reassuringly. "No way. We'll keep Moonbase going and we'll use our nanomachines no matter what laws they pass down there." Then he added, "I hope."

"It's really getting sick back home, you know," she said, suddenly glum. "The New Morality people keep passing new laws and the Supreme Court lets them get away with it. They've even shut down the national art museum in Washington!"

But Doug's mind was looking outward. "If only we could start the asteroid program now. If there was only some way I could get Greg to go for it."

"I could stay here," Bianca said. "I wouldn't mind staying here with you indefinitely."

"You want to become a real Lunatic?"

"Why not?"

"You're sure?"

She nodded gravely. I'm positive."

Again Doug caught a hint of something more going on than her words revealed. But he pushed that out of his thoughts. How can we can get the asteroid-grabbing program started right now? he asked himself.

Looking up, he saw that people were filing into The Cave, lining up at the food dispensers for their evening meals. He spotted Lev Brudnoy's tall, gangly form meandering through the rapidly-filling tables, a tray of food in his hands and a bemused, almost puzzled look on his grizzled face.

"Mr. Brudnoy," Doug called out, getting to his feet. "Would you care to join us?"

"Why? Are you falling apart?"

"Huh?'"

Brudnoy smiled sheepishly as he approached their table. "Forgive me. It's an gld Groucho Marx line and it's become something of a conditioned reflex in my silly little brain."

Doug didn't quite understand. "Marx? Like, with Lenin?"

With a sigh, Brudnoy said, "Please ignore my foolishness. And, yes, I would like to join you. I hate to eat alone."

"You were an astronaut, weren't you?" Doug asked as Brudnoy put his tray down on the table and folded his lanky frame into the chair between himself and Rhee.

"A cosmonaut," Brudnoy corrected. "The same thing, but in Russian."

"What do you think of the possibilities of going out and finding a carbonaceous asteroid and moving it into an orbit around the Moon?"

Brudnoy slumped back in his chair and puffed out his cheeks, then let out a long, slow whistle. "Ambitious. It would take a lot of delta vee."

"Change in velocity," Doug explained before Rhee could ask.

"I know that!" she hissed.

"Even for the Earth-crossing asteroids," Brudnoy said, half musing, "you would need a tremendous expenditure of propellant to change their momentum into a lunar orbit"

"Suppose we use the asteroid's own materials as propellant?" Doug challenged.

Brudnoy's shaggy brows went up. "It would have oxygen, wouldn't it."

Rhee said, "Carbonaceous chondrites contain water."

"Yes, of course."

"Hydrates," she said, "chemically linked to the rock."

"It would take energy to get the water from the rock."

"There's plenty of solar energy," Doug said. "And we can use nanomachines to do the separation."

"I see. Once you have water, of course, you have hydrogen and oxygen for rocket propellants."

"Right." Doug nodded eagerly.

"Of course, the trick is not to use up all the asteroid's valuable chemicals merely to get it into an orbit around the Moon. You want its water for us to use here, don't you?"

"And its carbon," said Doug.

"Carbon?" Brudnoy's shaggy brows rose. "For life support?"

"For making spacecraft out of diamond, using nanomachines," Doug said.

"Diamond," Brudnoy whispered.

"Stronger, lighter, more heat-resistant," said Doug. "And cheaper to manufacture, with nanomachines."

Brudnoy nodded, deep in thought, his dinner tray untouched. At last he asked, "Why bring the asteroid into lunar orbit?"

"So we can mine it," Doug said.

"You can mine it while it remains in its own orbit around the Sun. Then all you need to bring back here are the materials you really want. Why drag the entire asteroid here? It's inefficient."

Doug thought about it for a moment. "Yes... that could work."

"You see, my young friend, in space distance is not so important as the amount of energy you must expend to get the job done."

Doug nodded agreement. "And it would take much less energy to bring the raw materials we want from the asteroid to Moonbase than it would to move the whole asteroid into a lunar orbit. I see."

"Much less energy," said Brudnoy, smiling approvingly at Doug. "Which means much less rocket propellant."

"Which means much less money," said Doug.

Brudnoy patted Doug's shoulder. "You understand it very well."

Rhee pointed to Brudnoy's tray. "Your dinner's getting cold."

Glancing down at the plastic dishes, Brudnoy said, "It's almost criminal how the cooks take the fruits of all my hard labor and turn it into unappetizing mush."

"Maybe we need a good chef up here," Rhee said, grinning.

Brudnoy nodded dolefully: ''We certainly need someone who can create something better than this. Look, even the salad is soggy and lifeless."

But he stuck a fork into it anyway. "I raised these sad little leaves. They were crisp and cheerful when I handed them over to the cooks."

Doug had never given much thought to the quality of the meals. He ate what was available.

Munching thoughtfully, Brudnoy swallowed and asked, "What will you use for a spacecraft?"

"Adapt a lunar transfer ship, I suppose," Doug replied.

"You will need a team of engineers and technicians."

"We already have an astronomer to pick out the most likely asteroid." Doug jabbed a thumb in Rhee's direction.

"Congratulations." Brudnoy lifted his tea mug to her. "But if you don't mind my saying so, you're going to need more than the three of us to accomplish this task."

"Three of us? You mean you're willing to help us?"

"Of course."

"Terrific!" said Doug, tremendously pleased.

They clinked their cups together.

"We'll take one of the LTVs and have it modified for the mission," Doug said, his insides beginning to tremble with growing excitement "Do you have the facilities for modifying spacecraft here?" Rhee asked.

"No, but the corporation has space stations that can do that kind of work. In Earth orbit."

Brudnoy's enthusiasm was muted. "Why do it at a space station?" he asked, jabbing at another piece of salad on his tray. "Why not do it here?"

"We don't have the facilities here," Doug said.

"We could adapt what we do have," said Brudnoy. "We have the talent, too, if we use our people properly."

Doug gaped at him. "Modify the LTV here," he muttered.

"Do the entire job here at Moonbase," Brudnoy said firmly.

"Do you think we could build the Clipperships here at Moonbase?" Doug asked.

"Why not? The nanomachines don't care where they are."

"That would mean turning Moonbase into a major manufacturing center."

"Why not?" the Russian repeated, smiling patiently. "After all, I can feed you lapin a la Brudnoy now, although I shudder to think of what the cooks would do with it. Why not take the next step forward?"

"From a mining center to a manufacturing center," Doug mused.

"A natural step in the evolution of a frontier settlement. It will allow us to expand from a town into a city."

"Wow," said Rhee. "This is getting awesome."

But Doug sagged back in his chair. "We'd need a lot of additional capital investment."

"Of course."

Rhee sensed Doug's sudden change of mood. "The corporation won't put up the money?"