Momentum Exchange Tether

A momentum exchange tether is one of many applications for space tethers, used to adjust the orbit of a spacecraft. Due to the centrifugal acceleration, the act of spinning a long tether will create a controlled force on the end-masses of the system. While the tether system spins, the objects on either end of the tether will experience continuous acceleration; the magnitude of the acceleration depends on the rotation rate. Momentum exchange can occur if an end body is released during the rotation. The transfer in momentum to the released object will cause the system to lose orbital energy, and thus lose altitude. However, using electrodynamic tether thrusting, the system can then re-boost itself without the expenditure of consumable reaction mass.