been almost leveled in her absence. She stood on the edge of the hole, looking down in it. They were going to build to a design that she liked tremendously, one she had worked on herself in Antarctica and on the Ares: a simple line of barrel-vaulted chambers, sharing adjacent walls. By setting them in the trench the chambers would be half-buried to begin with; then when completed they would be covered by ten meters of sandbagged regolith, to stop radiation and also, because they planned to pressurize to 450 millibars, to keep the buildings from exploding. Local materials were all they needed for the exteriors of these buildings: Portland cement and bricks were it, basically, with plastic liner in some places to insure the seal.
Unfortunately the brickmakers were having some trouble, and they gave Nadia a call. Nadia’s patience was running short, and she groaned. “We travel all the way to Mars and you can’t make bricks?”
“It’s not that we can’t make bricks,” said Gene. “It’s just that I don’t like them.” The brickmaking factory mixed clays and sulphur extracted from the regolith, and this preparation was poured into brick molds, and baked until the sulphur began to polymerize, and then as the bricks cooled they were compressed a bit in another part of the machine. The resulting blackish-red bricks had a tensile strength that was technically adequate for use in the barrel vaults, but Gene wasn’t happy. “We don’t want to be at minimum values for heavy roofs over our heads,” he said. “What if we pile one too many sandbag on top of it, or if we get a little marsquake? I don’t like it.”
After some thought Nadia said, “Add nylon.”
“What?”
“Go out and find the parachutes from the freight drops, and shred them real fine, and add them to the clay. That’ll help their tensile strength.”
“Very true,” Gene said, after a pause. “Good idea! Think we can find the parachutes?”
“They must be east of here somewhere.”
So they had finally found a job for the geologists that actually helped the construction effort. Ann and Simon and Phyllis and Sasha and Igor drove long-distance rovers over the horizon to east of the base, searching and surveying far past Chernobyl, and in the next week they found almost forty parachutes, each one representing a few hundred kilos of useful nylon.
One day they came back excited, having reached Ganges Catena, a series of sinkholes in the plain a hundred kilometers to the southeast. “It was strange,” Igor said, “because you can’t see them until the last minute, and then they’re like huge funnels, about ten kilometers across and a couple deep, eight or nine in a row, each smaller and shallower. Fantastic. They’re probably thermokarsts, but they’re so big it’s hard to believe it.”
Sasha said, “It’s nice to see such a distance, after all this near horizon stuff.”
“They’re thermokarsts,” Ann said. But they had drilled and found no water. This was getting to be a concern; they hadn’t found any water to speak of in the ground, no matter how far down they drilled. It forced them to rely on the supplies from the air miners.
Nadia shrugged. The air miners were pretty tough. She wanted to think about her vaults. The new improved bricks were appearing, and she had started the robots building the walls and roofs. The brick factory filled little robot cars, which rolled like toy rovers across the plain to cranes at the site; the cranes pulled out bricks one by one, and placed them on cold mortar spread by another set of robots. The system worked so well that soon the bottleneck became brick production itself. Nadia would have been pleased, if she had had more faith in the robots. These seemed okay, but her experiences with robots in the years on Novy Mir had made her wary. They were great if everything went perfectly, but nothing ever went perfectly, and it was hard to program them with decision algorithms that didn’t either make them so cautious that they froze every minute, or so uncontrolled that they could commit unbelievable acts of stupidity, repeating an error a thousand times and magnifying a small glitch into a giant blunder, as in Maya’s emotional life. You got what you put into robots, but even the best were mindless idiots.
• • •
One evening Maya snagged her out in her tool room and asked her to switch to a private band. “Michel is useless,” she complained. “I’m really having a hard