The space city orbits the sun in the asteroid belt where raw materials are plentiful. The city is gravity gradient stabilized and always points the radiation shield toward the sun. There is no spin or rotation of the city, so the residents spend their lives in zero gravity. Consequently, space vehicles can approach and dock to the city from just about any direction.
Energy is gathered from the sun in two ways. The eight long structures attached at the end away from the sun are mirrors that reflect sunlight into the rows of windows on the four residential pressure vessels. The light is used for illumination and agriculture and also provides heat.
There are eight photovoltaic solar arrays, four mounted on the radiation shield, and four mounted on the end structure that is away from the sun. These solar arrays provide electric power for the city.
Each residential pressure vessel is made from aluminum obtained from rocky asteroids. Each vessel is 23 meters (75 feet) in diameter and 175 meters (575 feet) long, with a wall thickness of 1/4 meter (10 inches). The walls of the residential pressure vessels provide protection from cosmic rays, which unlike solar radiation, can come from any direction.
People will evolve in space to become adapted to zero gravity and increased exposure to radiation. For example, when going outside the residential pressure vessels, a resident will be exposed to solar radiation or cosmic rays while space-walking (working in a space suit) or commuting in lightweight space vehicles.
Obtaining material resources from asteroids makes sense because there is no gravity well traversal required which would take significant energy and reaction mass. In many cases, asteroids will drift slowly by the city and can be captured by robotic spacecraft. In other cases, asteroids will be further away and will need to be captured and propelled to the city for processing.
Some asteroid ore processing operations can be performed inside the pressurized space, and some can be performed outside. For example, large concentrating mirrors can be used outside the city for melting of large asteroids for molding into radiation shielding and other purposes.
Space cities will not need to be entirely self-sufficient. Trade among cities in similar orbits will be the easiest energetically, but trade with societies in gravity wells (Earth, the Moon, and Mars) will also be feasible for high value to mass ratio commodities.
Some cities may use artificial gravity from being spun, but the structural costs of doing so may make it somewhat rare. It is conceivable that some centrifuge hotels may be constructed, but it is likely that many space residents of the future will spend their entire lives without experiencing walking in a gravitional field.
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SpaceCity.html, this hand crafted HTML file was created March 7, 2007 .
Last updated July 5, 2011, by Rick Wagner. Copyright © 2007-2011, all rights reserved.