Orbital (space habitat)

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Illustration of an orbital created by Giuseppe Gerbino.

In Iain M. Banks' fictional Culture universe, an orbital is a purpose-built space habitat.

Banks has described them as looking like "a god's bracelet" hanging in outer space. Orbitals are ribbon-like hoops of super strong material (see also unobtainium) reinforced and joined with force fields. On the inside of the hoop there can be any type of planetary environment from desert to ocean to jungle to glacier. At the edges are high walls to keep the atmosphere in and protect the inhabitants from radiation. The walls are typically tens or hundreds of kilometres high.

Orbitals spin to mimic the effects of gravity and are sized so that the rate of rotation necessary to produce a comfortable gravity level is approximately equal to one day. In the case of the standard Culture day and gravity, this diameter is around four million kilometres. By tilting the axis of the orbital relative to its orbit around a star a convenient day-night cycle can be experienced by the inhabitants.

The Culture's orbitals are each governed and managed by a Mind, which is situated in a structure in space at the centre of the Orbital, known as the Hub. The Mind is generally referred to simply as "Hub" by the inhabitants of the orbitals. Other civilisations also built orbitals, however, and it is not clear that all are so-managed.

Vavatch Orbital is the setting for a large part of Consider Phlebas; Masaq Orbital for Look to Windward. In both books attempts are made to destroy the habitats. Vavatch is destroyed by the Culture after an ultimatum to stop it falling into Idiran hands and Masaq is the target of a Chelgrian revenge strike on its hub.

An orbital is similar to a ringworld but is much smaller and does not enclose its primary star within itself, instead orbiting the star in a more conventional manner. Many different civilizations use orbitals sized according to the preferences of the builders; the Culture's orbitals are approximately ten million kilometres in circumference and have widths varying between one thousand and six thousand kilometres. Vavatch, a non-Culture orbital seen in Consider Phlebas, had a circumference of fourteen million kilometres and a width of thirty-five thousand kilometres - significantly larger than the orbitals built by the Culture - and produced greater simulated gravity.

The computer game is set on a structure similar to an orbital.

External links

["A Few Notes on The Culture"]

Orbital (space habitat)

External links

See also