Then the sun would crack the horizon, and Nadia would be done with her cereal and milk, the milk made of powder mixed with water mined from the atmosphere (it tasted just the same); and it was time to get into her walker, and out to work.

The walkers were designed for the martian surface, and were not pressurized like spacesuits, but were rather made of an elastic mesh, which held in the body at about the same pressure that the terran atmosphere would have. This prevented the severe expansion bruising that would result if skin were exposed to Mars's minimal atmosphere, but it gave the wearer a lot more freedom of movement than a pressurized spacesuit would have. Walkers also had the very significant advantage of being fail-operational; only the hard helmet was airtight, so if you ripped a hole at knee or elbow you would have a badly bruised and frozen patch of skin, but would not suffocate and die within minutes.

Getting into a walker, however, was a workout in itself. Nadia wriggled the pants over her long underwear, then the jacket, and zipped the two sections of the suit together. After that she jammed into big thermal boots, and locked their toprings to the suit's ankle rings; pulled on gloves, and locked the wristrings; put on a fairly standard hard helmet, and locked it to the suit's neck ring; then shouldered into an airtank backpack, and linked its air tubes to her helmet. She breathed hard a few times, tasting the cool oxygen-nitrogen in her face. The walker's wristpad indicated that all the seals were good; and she followed John and Samantha into the lock. They closed the inner door; the air was sucked back into containers; John unlocked the outer door. The three of them stepped outside.

It was a thrill every morning to step out onto that rocky plain, with the early morning sun casting long black shadows to the west, and the various small knolls and hollows revealed clearly. There was usually a wind from the south, and loose fines moved in a sinuous flow over the ground, so that the rocks sometimes seemed to creep. Even the strongest of these winds could scarcely be felt against an outstretched hand, but they hadn't yet experienced one of the storm winds; at five hundred kilometers per hour they were pretty sure to feel something. At twenty, nearly nothing.

Nadia and Samantha walked over to one of the little rovers they had uncrated, and climbed in. Nadia drove the rover across the plain to a tractor they had found the day before, about a kilometer to the west. The morning cold cut through her walker in a diamond pattern, as the result of the X weave of the heating filaments in the suit material. A strange sensation, but she had been colder in Siberia many a time, and she had no complaints.

They came to the big lander and got out. Nadia picked up a drill with a Phillips screwdriver bit, and started dismantling the crate on top of the vehicle. The tractor inside the lander's crate was a Mercedes-Benz. She poked the drill into the head of a screw, pulled the trigger and watched the screw spin out. She moved to the next, grinning. Innumerable times in her youth she had gone out in cold like this, with numb white chopped-up hands, and fought titanic battles to unscrew frozen or stripped screws. . . . but here it was Ziiip, another one out. And really with the walker it was warmer than it had been in Siberia, and freer than in space, the walker no more restrictive than a thin stiff wetsuit. Red rocks were scattered all around in their uncanny regularity; voices chattered on the common band: "Hey, I found those solar panels!" "You think that's something, I just found the goddamn nuclear reactor." Yes, it was a great morning on Mars.