Advantages of using an elliptically-orbiting tethered-dumbbell system for a satellite transfer to geosynchronous orbit

This paper examines the use of an elliptically-orbiting tethered-dumbbell (Space Shuttle-satellite) system for satellite transfer to geosynchronous altitude. The two-dimensional rigid body equations of motion are derived using a Lagrangian method. Integration of these equations yields the system states, from tether deployment through payload release. These states are used to predict the ΔV savings (compared to a Hohmann transfer) when the payload is given a “forward swing zero libration” release, that is, the payload is released on a forward swing when the libration angle is instantaneously zero. By varying the pre-deployment true anomaly, the “forward swing zero libration” is caused to occur nearly simultaneously with periapse passage, resulting in maximum Δ V savings. The system deployment velocity and tether length were also varied to observe their effect on Δ V savings.