Continuous earth-moon payload exchange using motorised momentum exchange tethers

To benefit from the abundance of resources available at the Moon's surface; a permanent lunar base must be established which has the capability of extracting these resources in conjunction with an economical means for their return to Earth. Replenishment of any resources required by the base must also be accomplished. However, at present, conventional chemical propulsion systems do not satisfy these economic constraints. Hybrid systems consisting of symmetrically laden motorised momentum exchange tethers and conventional chemical propulsion are capable of replacing the sole use of chemical propulsion at reduced fuel expenditure. The exchange of payloads between the Earth and the Moon occurs at the ascending and descending nodes of the Moon's orbit about Earth and by utilising a combination of precise logistical arrangement and trajectory design allows a continuous exchange of payloads between the Earth and the Moon to be accomplished. The advantages of the system are; a reduction in fuel expenditure in comparison with the exclusive use of chemical propulsion and the frequency of exchange opportunities available. Adaptations to the system may provide configurations suitable for exchanges between the Earth and Mars or the Earth and Near Earth Objects, NEOs.