Delivery of secondary payloads to custom orbits using EDDE

"EDDE" (the ElectroDynamic Delivery Express) is a persistently maneuverable propellantless "taxi" vehicle for low earth orbit (LEO). EDDE has at least 2 major applications: delivery of secondary payloads to custom orbits throughout LEO, and removal of large orbital debris. This paper focuses on payload delivery. A companion paper in session A6.6 focuses on debris removal. EDDE consists mostly of a multi-kilometer reinforced aluminum foil tape that collects and conducts electrons, plus solar arrays to drive the current. Hot wires emit electrons back into the ambient plasma, allowing external closure of the current loop. The maneuver force comes from current in the tape crossing geomagnetic field lines. Efficient operation requires large electron collection areas and multi-kilometer tape lengths. Air drag sets a minimum altitude near ISS altitude. There is no hard ceiling, but efficient thrust at higher altitude requires longer and heavier EDDEs. EDDE is modular and may typically range from 20 to 80 kg for different missions. Distribution of secondary payloads by EDDE may often start in an orbit near the ISS (51.6° inclination, 350-420 km altitude) and end with release of payloads at any desired altitudes, nodes, and inclinations, including 97-99° sun-synch orbits. Large inclination and node changes may best be done 100 km above ISS. Once near the desired orbit plane, EDDE can quickly climb to desired payload release altitudes, up to about 1000 km. Secondary payload delivery times will typically be months. By comparison, waiting for a suitable launch directly to a specific desired orbit may take far longer. The most attractive thing about EDDE to smallsat owners may be "custom orbits without dedicated launch." A payoff to launch service providers is making surplus payload capacity on LEO launches usable to a much wider range of secondary payload customers. We recently matured EDDE design, components, and operating concepts under a 2-year contract with the NASA Space Technology Mission Directorate at Langley Research Center. This paper describes our work maturing components and design, typical nanosat delivery operations, and plans for 3U precursors and a 12U full test.