“George is a real nice guy, Zip,” said Joe, “but I still think he’s breathed a little too much vacuum for his own good. You have to experiment in life, sometimes.” “I want to learn more about this power system! This is amazing!” rhapsodized Mark. “If I’m right, this button here will...” He pressed it. Almost at once a stream of paper began to feed out of a slot to the right of the terminal and fell down, sheet by sheet, into a gathering tray. Mark picked up the first sheet. “It’s printing out the diagrams of the thrust system. just like that. You’re right, Joe--this place is _great_!” * * * * * On the northeast edge of the massive area on the surface of Mars called the Mare Hadriacum, stood a complex of domes and cylinders. Made of metal and glass, it stood on an open plain about 35 degrees south of the equator and 85 degrees east of the central meridian. The complex was one of five atmosphere-generating plants on Mars, and the only one in the southern hemisphere. In a small crater nearby was the settlement of New Emmaus, with a population of about 12,500. The long process of terraforming Mars had begun when a meteor shower struck the fourth planet in 2009, significantly raising the temperature of the atmosphere and altering the weather systems. With this jump start serendipitously provided by meteorites, Earth had hastened the process of making Mars livable by scattering the surface with spores and seeds, introducing desert--hardy animals, and establishing the five atmosphere-generating plants. Thanks to Earth’s efforts, the planet’s temperature had continued to rise. Eventually water had emerged from below ground and from the ice caps around the poles, and the air was gradually thickening. Terraformation had been taking place for almost 150 years, and it would be at least another two centuries before it would be possible to live anywhere on Mars without a spacesuit. The atmosphere-generating plants were critical to the process. The plants themselves were automated, with all systems operated and monitored by robots, and the major centers of population on Mars were located in craters not far from each plant. The complexes were on the open surface of the planet rather than in craters, but the air they created flowed first into the nearest depressions in the surface, and it was here that most settlements were located. The plant located in the southern hemisphere was the most remote, but had been filling the Mare Hadriacum, locally known as the Red Sea, for decades. This great depression was 2,500 miles in diameter. When much of the southern ice cap had melted, it filled the Red Sea with water up to about three-fourths capacity, making the region a delightful place for quiet living.