The Sunborn by Gregory Benford Read Free Book Online Page B

Nothing could live on the surface, of course, in the stinging oxidants and lethal ultraviolet. But the Marsmat could not contain its moist hoard perfectly.
    Gusev Crater had thermal vents because the huge ancient impact had cracked the underlying layers, letting magma worm upward. The best place to go deeper into Mars seemed to be at the bottom of Valles Marineris. That great stretched scar cut deep and broad. The barometric pressure there could even allow a briny slush on a summer afternoon, melting long-frozen chemical reserves and maybe letting Marsmat get close to the surface.
    She was curious about how the mat had used the deadly surface for an energy source without getting stung by the ultraviolet and alkaline dusts. There were whole conferences Earthside on just that basic physiological riddle. To get any work done here, she had to keep an open mind. Mars did not reward fixed preconceptions.
    She looked up at the hard black sky. Faint filigrees fought up there. Probably ionization curls, she thought, from the solar storm streaming past Mars right now and slamming into the thin atmosphere.
    Survey done, she went back to grunt labor. Compared with decades before, the rover’s cable rig was first-class. It worked from a single heavy-duty winch, with a differential gear transferring power from one cable to the other depending on which sent a command. It was the same idea as the rear axle in a car and saved mass.
    Four telepresence robots were standing beside the fissure. They had six spindly arms, four stubby legs, and a big central control box, all in sleek polycarbon, and she no longer found them odd. These had done the first study, lowering themselves on cables to check for life. Long experience had shown that letting ’bots do a lot of the roving saved time and accidents.
    Sometimes Julia wondered if Mars could have been explored at all without plenty of ’bots. Sitting warm and snug in the habs, she and Viktor and rotations of crews from Earth had tried out dozens of candidate vents.
    In two decades they had found that most fissures, especially toward the poles, were duds. No life within the top kilometers, though in some there were fossils testifying to ancient mats’ attempted forays. Natural selection—a polite term for Mars drying out and turning cold—had pruned away these ventures. The planet’s axial tilt had wandered, bringing warmer eras to the polar zones, then wandering away again. Life had adapted in some vents, but mostly it had died. Or withdrawn inward.
    Not this vent, though.
    Somebody back at Gusev made the ’bots all turn and awkwardly bow as the humans approached. Julia laughed with the others, and, as if right on cue, Praknor came on the comm. No preliminaries.
    “You deliberately stood me up.”
    “Sorry, it was a scheduling mix-up,” Julia said.
    “I cannot believe—”
    “Hey, got work to do here. Talk later.” Julia cut off the long-range comm frequency and switched to local, 2.3 gigahertz. And felt an impish joy that turned up her lips. When she told Viktor, he smiled, too, with an expression she had come to cherish. Long relationships had their rewards.
    First, as always, they set up the base camp. The team was quick and precise, hustling in the forward-leaning trot that was the most energy-efficient way to move on Mars. Every expedition now, there was new tech to make jobs easier, like the ball tents. She watched them deploy, nearly without human effort.
    Under pressure any object wants to shape into a sphere. The ball tents took advantage of this. The ball was made of a flexible, thermally insulating material that could take wear and tear, especially the constant rub of dust. Light wires or ropes anchored the ball to the ground as an air tank inside inflated it, with the people already inside. A small chem cracking plant squatted beside each ball, running steadily to split the atmosphere’s CO 2 for oxygen. Adding hydrogen from water let the cracker build up stocks of methane