small pioneer stations. We filed past warrens once used by the earliest families, dark and bitterly cold, kept pressurized in reserve only for dire emergencies” (8). Now Martians live in domed trench complexes, well protected but still vulnerable to pressure-loss accidents and power failures leading to oxygen deprivation and recycler failures. When political crisis explodes, “the white walls and pressure arches [of the new Mars capital] stood out against the ochre and red all around, a beacon for assault” (367)—although it will prove to survive.
Descriptions of cities are secondary in Bear’s narrative, but they are central to Kim Stanley Robinson’s intentions in his trilogy about the terraforming of Mars. He opens the first volume, Red Mars (1993), with a civic festival celebrating Nicosia, the planet’s first fully surface city, coming seventy-five years after initial settlement. “The first town of any size to be built freestanding on the Martian surface; all the buildings were set inside what was in effect an immense clear tent, supported by a nearly invisible frame.” The town is a large triangle on a slope (great views!) with seven radiating avenues and low buildings in Fauvist hues. Its five thousand residents have already divided into ethnic neighborhoods. The air has enough oxygen and weight that the city does not have to be fully sealed, but the atmosphere is still so thin and cold that one cannot survive for long outside without protective suits. “After all those years in Underhill it was hard to grasp…. We’re out of our holes, Maya, we’re on the surface at last” (4–6, 19).
Decades earlier in Robinson’s planetary epic, Martian settlement had started with an expedition camp of modules scattered on the surface, such as might be found in Antarctica or Greenland. Soon Underhill is built as a permanent underground habitat. A double glass dome holds the pressure and keeps out ultraviolet radiation, roofing over a central atrium, with underground rooms branching off. “The sky was a ruby color through the glass panels, and the magnesium struts gleamed like tarnished silver” (163). Settlers built other habitats also largely underground, but with gradually increasing exposure, such as a set of rooms dug into the side of a thirty-meter trench, with three levels of stacked rooms faced with glass, and reflective material on the other side of the trench to direct sunlight. Then the increasingly confident Martians scaled up that model. Japanese immigrants built Senzeni Na, an industrial community at the bottom of Thaumasia Fossae’s deepest canyon. Production facilities on the canyon floor are connected by walktubes because pressure suits were still needed outside. “The town’s actual living quarters were built into the southeast wall of the canyon. A big rectangular section of the cliff had been replaced by glass; behind it was a tall open concourse, backed by five stories of terraced apartments.” The biggest and most beautiful new city is Burroughs, the de facto capital as the base of the United Nations Office of Mars Affairs. It is another cliff city, carved into a set of mesas: “Big sections of the mesas’ vertical sides had been filled by rectangles of mirrored glass, as if postmodern skyscrapers had been turned on the sides and shoved into the hills” (271).
The Martians revolt against Earth domination, UNOMA being the tool of big Earth corporations, but their cities are vulnerable to tent breach. They “lay helpless under the lasers of orbiting UNOMA police ships” (514). Refugees have crowded into Cairo, which is surrounded by UN police. “At 4:30 alarms went off all over the city. The tent had been broached, apparently catastrophically, because a sudden wind whipped west through the streets, and pressure sirens went off in every building. The electricity went off, and just that quick it went from a town to a broken shell, of running figures in walkers and helmets, all of them rushing about, crowding toward the gates, knocked down by gusts of wind and each other. Windows popped out everywhere, the air was full of clear plastic shrapnel” (529).
Heinlein, Clarke, Bear, and Robinson are all authors who respect engineering. Their Martian cities converge in appearance and structure because the logic of pressure gradients, oxygen pressure, and materials mandate a common form. Moreover, it is a form that readers with basic physics can understand, agree with, or critique. Engineering challenges and solutions are not another decorative gizmo like a bounce tube or dilating door, but rather essential background. In The Sands of Mars, for example, Clarke devoted several paragraphs to the completion of a seventh dome.
Hello, Earth. This is Martin Gibson speaking to you from Port Lowell, Mars. It’s a great day for us here. This morning the new dome was inflated and now the city’s increased its size by almost a half….
You know that it’s impossible to breathe the Martian atmosphere—it’s far too thin and contains practically no oxygen. Port Lowell, our biggest city, is built under six domes of transparent plastic held up by the pressure of the air inside—air which we can breathe comfortably though it’s still much less dense than yours.
For the last year a seventh dome has been under construction, a dome twice as big as any of the others….
Imagine a great circular space half a kilometre across, surrounded by a thick wall of glass bricks twice as high as a man. Through this wall lead the passages to the other domes, and the exits direct on to the brilliant green Martian landscape all around us….
When I entered Dome Seven yesterday, all this great circular space was covered with a thin transparent sheet fastened to the surrounding wall, and lying limp on the ground in huge folds beneath which we had to force our way…. The envelope of the dome is very strong plastic, almost perfectly transparent and quite flexible—a kind of thick cellophane. (422)
Several ensuing paragraphs describe the process of pumping in air and inflating the dome. The scene is perhaps not all that high on the sense-of-wonder scale, but Clarke knew that his own technical bent matched that of his readers.
CITIES UNDER THE SEAS
Underwater cities are the mirror image of lunar and Martian bubble cities. The basic challenge is to maintain a bubble of usable atmosphere within an environment at a different pressure. Dome breach is just as much a fear, but the problem is reversed—keeping massive overpressure at bay and preventing implosion rather than holding in air against explosive escape.
Underwater cities have seldom made for good fiction because of the storytelling problem of setting action in dark ocean depths where neither characters (nor readers/viewers) can see or move freely outside. Consider that submerged movies tend to be submarine warfare thrillers, mysterious shipwreck thrillers, or adventures revolving around alien objects that just happen to have fallen to the ocean floor. In The Abyss (1989), the best of the genre, ambience and action are dark and claustrophobic. A cinematic alternative like the cheesy Captain Nemo and the Underwater City (1969) offers implausibly cheerful interiors and no gestures to technical verisimilitude.
A pulp writer’s favorite option was to ignore science in favor of a mythical Venus with warm seas and networks of underwater cities. Henry Kuttner and C. L. Moore in Fury, originally serialized in Astounding in 1947, posited a set of undersea Venusburgs: “The Earth is long dead, blasted apart, and the human survivors who settled on Venus live in huge citadels beneath the Venusian seas in an atrophying, class-ridden society ruled by the Immortals—genetic mutations who live a thousand years or more.” The domes themselves, both beneath the waters and covering newer colonies on land, are made from “impervium.” What a handy material that is, excusing the authors from actually thinking through the engineering problems so they can focus the plot on tensions and conflicts within the ruling class. Nevertheless, impervium makes the machines for breathing possible: “Now he stood on the land of Venus, with a transparent impervium dome catching rainbows wherever the fugitive sun broke through the cloud blanket…. The free air of Venus was short on oxygen and long on carbon dioxide; it was breathable, but not vintage atmosphere…. Here, under the dome, the atmospheric ingredients were carefully balanced. Necessary, of course—just as the impervium shell itself seemed necessary against the fecund insanity that teemed the Venusian lands” (93).
Isaac Asimov left only part of his science at the door when he wrote for the juvenile market as Paul French,
