Free Jupiter Project by Gregory Benford

was already lowering nets of baggage from the cargo lock. We walked over and helped two men unroll the net. Our cases were in it. We scooped them up and started toward the base buildings. They housed some of the fifty permanent staff members; the rest lived under the life dome, further away.
    The Sagan ’s jet splash had melted the ground and made a brown spot in the ghostly white. We trotted along, my suit chuffing away to fight off the cold. When the first expedition landed here the surface was at 150 degrees Centigrade below zero. The reclamation project has warmed things up, but not much.
    We reached the administration building and banged on the lock. In a moment the green light winked on and we cycled through. We came out in a suiting-up room. I popped my helmet pressure and found the air was sweeter than I’d expected; they’re making improvements in the base all the time. We lugged our bags into the next room and found a man behind a counter with a clipboard.
    “Your name—oh, Palonski and Bohles. Welcome back. Gluttons for punishment, aren’t you? I see you asked for a Walker again.”
    “Better than refueling duty,” I said and he chuckled. Pumping water and ammonia into the Sagan ’s tanks is the most boring job imaginable; you watch dials for two hours, spend five minutes switching hoses, and then sit two hours again.
    He assigned us bunk numbers and let us go; the families with children would get a complete lecture on safety and a long list of things they couldn’t do. I’d heard the lecture ten times before and could probably give it about as well as he could.
    We found our bunks and stowed our gear without wasting any time. We didn’t want the mob to catch up with us. As soon as things were squared away Zak and I beat it across the base and trotted over to the dome lock.
    The dome is the whole point of Ganymede, for me. I was out of my suit and putting on tennis shoes almost before the air lock had stopped wheezing. I had to gulp a few times to adjust my inner ear to the dome’s pressure, but that was automatic. Anybody who has been in space learns to do that without thinking—or ends up with lancing ear pains when he forgets. Zak was just as fast, and we went through the door together.
    To anybody living on Earth I guess the dome wouldn’t be a big deal. But to me—I came out the door and just stood there, sopping it up. Overhead the dome arches away, supported by the air I was breathing. It rises to 500 meters in height and is five kilometers in diameter; a giant, life-filled blister on Ganymede. Inside the blister is the only spot where a man can walk without a suit.
    Zak and I trotted the klick to the ski shed. There is a funny nose-shaped hill under the dome, with one steep face and one shallow. We carried our skis up the difficult side and strapped them on. I stood looking out, surveying the land under the dome. Hills sloped into each other, making stream beds and narrow valleys. A late morning water fog rose from a marshland. Up near the top of the dome, so thin you had to have faith to see it, was a wisp of pearly cloud. Back at the edge, the way we had come, a few people were spreading out from the lock.
    “Come on!” I said, and pushed off. We started slowly and then began to weave, making long undulating patterns down the hill face. You don’t get as much speed in a lighter gravity, but you can make incredible turns and prolong the ride.
    We skied most of the afternoon, until there were too many on the slope. Then we took a hike around the dome to see what was new. The experimental farm had grown and most of the crops—adapted corn, root vegetables, apples—were doing well. The farm is the seed of what Ganymede will become, once the atmosphere project gets going, melting dirty ice to make air.
    With the greenhouse effect warming things up and microorganisms giving off oxygen, eventually a soybean will grow somewhere and then—well, then colonists will be panting down our necks,