Tethers

Tethers have been a crucial and versatile technology since the very beginnings of the Bountiful Sky project.

Electrodynamic Tethers
This type of tether uses a gravity gradient together with a magnetic field gradient to generate a charge differential between the two ends of the tether in order to generate electricity.

One design difficulty of an electrodynamic tether is the buildup of charge at the tips of the tether. It is not possible to "complete the circuit" in the obvious way, because a second conductor would simply build up a similar charge gradient as the first. The solution is to radiate free electrons at the "down" end, and attract them at the "up" end, effectively completing the circuit through the larger magnetosphere. Because of this "charge cloud" surrounding the tether tips, there is a limit to how closely together tether generators can be built.

Power Transmission
Power is most commonly transferred from the generating tether to the consuming facility by microwave beam.

Momentum Transfer Tethers
This type of tether uses a gravity gradient to generate momentum, adding velocity to two loads at opposite ends of the tether without the need to expend any fuel.