Image from Steve Bowers
This rotovator uses photovoltaic energy to raise its orbit when necessary
Device for transferring cargo or passengers from the atmosphere or near surface of a planet to outer space.

To utilize a rotovator for a comparative low energy planet to orbit transfer, a hypersonic shuttle takes a payload up to rendezvous with one end of a rotating tether, consisting of two artificial satellites joined by a line in tension and rotating around a common centre of gravity. Once the payload is attached the tether continues to rotate until the payload is in orbit, however with a lower centre of gravity.

For interplanetary transfer, a payload is attached to a rotovator in an elliptical planetary orbit which tosses it towards a neighboring planet, where a second tether meets it and rotates it into orbit or even directly to the surface on a low gravity moon. The kinetic energy acquired by the receiving tether can be used in part to return payloads and maintain a dynamic equilibrium. If the tether loses too much knetic energy the shortfall can be replaced using photovoltaic panels or other forms of propulsion.

These systems are popular with developing solar systems in the outer volumes where energy and advanced technology are expensive. Large extravagant rotovator systems are used in many MPA systems, apparently just for entertainment and general exuberance. Most advanced polities and angelnet protectorates prefer static space elevators using advanced materials and powered orbital transfers giving the advantage of controllability.
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Development Notes
Text by Steve Bowers
Initially published on 03 July 2002.