Description Momentum exchange space tethers work on the principle of the transfer of linear and angular momentum from a source to a payload in a manner that can be harnessed for propulsion of the payload through space. The source can be another mass and the overall system is excited simply due to the laws of orbital mechanics, or it can be in the form of a prime mover such as an electric motor, operating in addition to the orbital effects. In this project the main objective will be to consider some work done on mtorised tethers which operate in so-called 'staged' pairs in order to increase the overall 'deltavee' obtainable for propulsion but not at the expense of impractically high stresses within the tether. This reduces the need for exotic materials in bulk and means that the tethers can be made up from conventional high-strength polymers.  The main aim of this project will be to examine the mission logistics of a pair of staged tethers operating between LEO and LLO, for the two-way exchange of payload material between the Earth and the Moon. Key Objectives

1. To re-consider some previous work done on staged tethers with a view to establishing a set of design parameter values for a system that may be practical to deploy in LEO and LLO, for a mission to exchange relatively large payloads between the Earth and the Moon.
2. Then to design the tether system from an energetic perspective to decide if this mission could, in fact, be operated on a regular basis.
3. Finally to consider how such a propulsion system could be sustainably driven, ideally using solar electric power.