Technologies for Momentum-Exchange/Electrodynamic-Reboost Tether Facilities

The MXER Tether Boost Facility will serve as a fully-reusable in-space ?upper-stage? that will provide propellantless propulsion for orbital transfer and Earth-to-Orbit launch assist. By elimi-nating the need to launch an upper stage along with each payload, the MXER Tether can reduce the size of the launch vehicle needed to deploy the payloads, achieving dramatic reductions in total launch costs. In the Phase I effort, we successfully developed an architecture that will en-able MXER tethers to be constructed using small modular components that can be designed, tested, and mass-produced at low cost. We demonstrated methods for fabricating high-strength tether structures, for protecting the high-strength materials in the tethers from the atomic oxygen environment, and for providing the high voltages and high powers needed to enable the MXER system to restore its orbit using propellantless electro-dynamic propulsion. In the Phase II effort, we will develop tools for performing design trade studies of MXER Tether Systems. We will then use these tools to design a flight demonstration mission that will bring the components needed to build an operational MXER tether up to a TRL of 8. We will develop and test new methods and algorithms for controlling the dynamics of MXER tethers. Finally, we will design, build, and test a prototype tether deployer module suitable for use in both the flight demonstration and the opera-tional MXER tether.