Moon & Mars Orbiting Spinning Tether Transport - Tethers Unlimited

Tethers Unlimited, Inc.MMOSTT Final ReportTether Boost Facility are added to this figure, this quick comparison indicates that a tethertransport system could reduce the launch costs to the customer by 50%-80%.One of the results of the initial tether boost facility design was that a tether facility capableof tossing 5,000 kg to GTO would require a total on-orbit mass of approximately 50 metric tons.Currently, a launch vehicle capable of placing 50 metric tons in orbit does not exist. Should theneeds of NASA’s HEDS program or other government-led initiatives result in the developmentof the proposed “Magnum” launch rocket, it may become possible to deploy such a tetherfacility in one launch. In the absence of such a beefy rocket, however, a tether boost facility willeither have to be sized for a smaller vehicle, and thus sized for a smaller payload, or will requiremultiple launches and on-orbit assembly.In order for the development of a Tether Boost Facility to be affordable for a commercialventure, it will be vital for the facility to be capable of performing a useful, revenue-generatingservice after the first launch. Consequently, our design effort evolved the system concept intoone that would be capable of being launched on a single large launch vehicle expected to be inservice in 2010. This facility would initially have a smaller payload capacity, but would bedesigned in a modular fashion so that its capacity can be increased to service 5,000 kg and largerpayloads:2. 2,500 kg Payload Modular Tether Boost FacilityAppendix C, “Design and Simulation of a Tether Boost Facility for LEO⇒GTO PayloadTransport” presents the concept design for a modular Tether Boost Facility capable of boosting2,500 kg payloads from LEO to GTO. Using analytical methods, we developed designs for theorbital mechanics and system sizing of the tether facility. The orbital designs were chosen sothat the payload and tether orbits are synchronous, so that the tether will have multipleopportunities to capture a payload with minimal maneuvering requirements. These designsaccount for orbital perturbations due to Earth oblateness. The tether facility power system issized to enable a throughput of one payload every 30 days. The entire tether facility is sized toenable an operational capability to be deployed with a single Delta-IV-H launch. The system isdesigned in a modular fashion so that its capacity can be increased with additional launches.The tether facility can also boost 1000 kg payloads to lunar transfer orbits, and will serve as thefirst building block of an Earth-Moon-Mars Tether Transportation Architecture.Appendix F. : “Tether Boost Facility Design Study Final Report” presents the details of thesubcontract effort by Boeing to define a system-level design for this initial operational tetherfacility, and Table 1 presents a summary of the design. The tether facility is sized at 19,891 kg tobe launched into LEO on a single Delta IV-H rocket, and will retain the Delta IV’s upper stagerocket as ballast mass, giving it a total operational mass of 23,358 kg.10