in a square, and Nadia was going to do it; as Arkady pointed out, it would then be possible to roof the area enclosed by the square. “That’s where those magnesium beams will come in handy,” Nadia said. “If only we could make stronger glass panes. . . .”
They had finished two sides of the square, twelve chambers entirely done, when Ann and her team returned from Hebes. Everyone spent that evening looking at their videotapes. These showed the expedition’s rovers rolling over rocky plains; then ahead there appeared a break extending all the way across the screen, as if they were approaching the edge of the world. Strange little meter-high cliffs finally stopped the rovers, and the pictures bounced as one explorer got out and walked with helmet camera turned on.
Then abruptly the shot was from the rim, a one-eighty pan shot of a canyon that was so much bigger than the sinkholes of Ganges Catena that it was hard to grasp. The walls of the far side of the chasm were just visible on the distant horizon. In fact they could see walls all the way around, for Hebes was an almost-enclosed chasm, a sunken ellipse about two hundred kilometers long and a hundred across. Ann’s party had come to the north rim in late afternoon, and the eastern curve of the wall was clearly visible, flooded by sunset light; out to the west the wall was just a low dark mark. The floor of the chasm was generally flat, with a central dip. “If you could float a dome over the chasma,” Ann said, “you’d have a nice big enclosure.”
“You’re talking miracle domes, Ann,” Sax said. “That’s about ten thousand square kilometers.”
“Well, it would make a good big enclosure. And then you could leave the rest of the planet alone.”
“The weight of a dome would collapse the canyon walls.”
“That’s why I said you’d have to float it.”
Sax just shook his head.
“It’s no more exotic than this space elevator you talk about.”
“I want to live in a house located right where you took this video,” Nadia interrupted. “What a view!”
“Just wait till you get up on one of the Tharsis volcanoes,” Ann said, irritated. “Then you’ll get a view.”
There were little spats like that all the time now. It reminded Nadia unpleasantly of the last months on the Ares. Another example: Arkady and his crew sent down videos of Phobos, with his commentary. “The Stickney impact almost broke this rock in pieces, and it’s chondritic, almost twenty percent water, so a lot of the water outgassed on impact and filled the fracture system and froze in a whole system of ice veins.” Fascinating stuff, but all it did was cause an argument between Ann and Phyllis, their two top geologists, as to whether this was the real explanation for the ice. Phyllis even suggested shipping water down from Phobos, which was silly, even if their supplies were low and their demand increasing. Chernobyl took a lot of water, and the farmers were ready to start a little swamp in their biosphere, and Nadia wanted to install a swimming complex in one of the vaulted chambers, including a lap pool, three whirlpool baths, and a sauna. Each night people asked Nadia how it was coming along, because everyone was sick of washing with sponges and still being dusty, and of never really getting warm. They wanted a bath— in their old aquatic dolphin brains, down below the cerebrums, down where desires were primal and fierce, they wanted back into water.
So they needed more water, but the seismic scans were finding no evidence of ice aquifers underground, and Ann thought there weren’t any in the region. They had to continue to rely on the air miners, or scrape up regolith and load it into the soil-water distilleries. But Nadia didn’t like to overwork the distilleries, because they had been manufactured by a French-Hungarian-Chinese consortium, and were sure to wear out if used for bulk work.
But that was life on Mars; it was a dry place. Shikata ga nai.
“There are always choices,” Phyllis said to that. This was why she had suggested filling landing vehicles with Phobos ice, and bringing it on down. But Ann thought that was a ridiculous waste of energy, and they were off again.
• • •
It was especially irritating to Nadia because she herself was in such a good mood. She saw no reason to quarrel, and it disturbed her that the others didn’t feel the same.