Resumen
The invention relates to a system for generating electrical power in orbit by means of floating conductive tethers, the system being mounted on a space vehicle (1) and comprising: two sets of bare (without electrical insulation) electrodynamic conductive tethers (2, 3) respectively connected to each of two poles (4, 5) of a system (6) for using or storing electrical power, each set being formed by at least one conductive tether. In the presence of plasma and a magnetic field, as it is the case of a satellite orbiting in the Earth's ionosphere, an electric current flows naturally along the conductive tethers, providing electrical power. The amount of electrical power obtained depends on the space environment, the velocity of the satellite relative to the plasma, and the properties and design of the tethers (length, cross-section and material). The system can be optimised by using materials that enhance the emission of electrons by means of a thermionic or photoelectric effects. Such materials are used in the composition of the tethers or to cover the surface thereof along the entirety or parts of the extension thereof.
Reivindicaciones
1. A system for generating electrical power in orbit by means of floating conductive tethers characterised in that it comprises two sets of bare (without electrical insulation) electrodynamic conductive tethers (2, 3) respectively connected to each of two poles (4, 5) of a system (6) for using or storing electrical power, each set being formed by at least one conductive tether. 2. The system according to claim 1 wherein each set of conductive tethers made up of two or more conductive tethers has the tethers thereof connected electrically to each other throughout the extension thereof in one or more points. 3. The system according to any one of claims 1, 2, wherein at least one of the electrodynamic tethers has an end mass connected at the tether end that is furthest from the system used for using or storing electrical power. 4. The system according to claim 3 wherein the end mass comprises at least one of the following elements: passive ballast mass, deployment system for tethers, another satellite or satellite cover. 5. The system according to any one of claims 1, 2, 3, 4, wherein at least one of the electrodynamic tethers thereof has a substantially circular cross section. 6. The system according to any one of claims 1, 2, 3, 4, wherein at least one of the electrodynamic tethers has a substantially annular cross section. 7. The system according to any one of claims 1, 2, 3, 4, wherein at least one of the electrodynamic tethers has a substantially tape-like cross section. 8. The system according to any one of claims 1, 2, 3, 4, 5, 6, 7, wherein at least one of the electrodynamic tethers is made up of a material that facilitates the emission of electrons by thermionic effect or photoelectric effect. 9. The system according to claim 8 wherein the material that facilitates the emission of electrons by thermionic effect comprises at least one of the following compounds: LaB<6> , CeB<6> , BaO-W, Ba-W, BaO, and 12CaO-7Al<2> O<3> (C12A7:e<-> ). 10. The system according to claim 8 wherein the material that facilitates the emission of electrons by photoelectric effect comprises at least one alkaline metal or one of the compounds Ag-Cs<2> O-Cs, Ag-Cs<3> Sb and Na<2> KSb. 11. The system according to any one of claims 1, 2, 3, 4, 5, 6, 7, wherein one or more of the electrodynamic tethers is made up of a conductive substrate coated along the complete extension thereof or a portion of it by a material that facilitates the emission of electrons by thermionic effect or photoelectric effect. 12. The system according to claim 11 wherein the material that facilitates the emission of electrons by thermionic effect comprises at least one of the following: LaB<6> , CeB<6> , BaO-W, Ba-W, BaO, and 12CaO-7Al<2> O<3> (C12A7:e-). 13. The system according to claim 11 wherein the material that facilitates the emission of electrons by photoelectric effect comprises at least one alkaline metal or one of the compounds Ag-Cs<2> O-Cs, Ag-Cs<3> Sb, and Na<2> KSb. 14. The system according to any one of claims 1, 2, 3, 4, 5, 6, 7, wherein one or more of the electrodynamic tethers is coated along the complete extension thereof or a portion of it by an insulating material. 15. The system according to any one of claims 1, 2, 3, 4, 5, 6, 7, 11, 12, 13, 14, wherein at least one of the electrodynamic tethers is substantially manufactured from materials that comprise at least one of the following: graphene, Aluminium alloys, Beryllium-Copper alloys. 16. The system according to claim 15 wherein the surface of one or more of the tethers thereof has been prepared to reach a high ratio of thermal absorptivity/emissivity with the aim of obtaining high temperatures that favour the thermionic emission of the coating.
