Server Sky - Data Centers in Orbit

Server Sky is a proposal to build large arrays of 7 gram paper-thin solar-powered computer satellites launched into a 6400 kilometer altitude earth orbit. A server-sat is mostly a 100 micron thick, 6 inch solar cell, with processor memory and radio chips around the edges. Server-sats use light pressure for thrust and electrochromic light shutters for steering. Thousands of server-sats will be positioned in three-dimensional arrays, about 100 meters on a side. An array acts as a large phased array antenna transmitting thousands of communication beams simultaneously to ground receivers and to other arrays in space. In space, there is room for thousands of these arrays, with the total population limited by night sky light pollution. A server-sat displaces 25 watts of ground-based electrical generation, cooling, and power conversion. A server-sat does not need the racks, cabling, power converters, land, buildings, and other infrastructure needed to build a ground-based server farm. These savings alone may pay for launch. The space solar energy available for server-sats is practically unbounded. Server-sat arrays operate outside the biosphere, so the environmental impact of power generation and heat disposal is close to zero. In time, thinner server-sats, new launch techniques, and solar cells made from lunar materials may further reduce the environmental and economic costs of manufacturing and launch. Thus, earth can return to what it is good at - green and growing things - while space can be filled with gray and computing things