Session
Technical Session III: Advanced Technologies I
Abstract
"EDDE" (the ElectroDynamic Delivery Express) is a persistently maneuverable modular propellant-less vehicle for low earth orbit (LEO). EDDE has at least 2 major applications: payload delivery and debris removal. Vehicles as light as 20-30 kg can deliver secondary payloads to custom orbits, but 50-100 kg vehicles plus capture hardware are needed to efficiently remove orbital debris above 800 km. EDDE uses a reinforced aluminum foil tape to collect and conduct electrons, and solar arrays distributed along the length to limit peak local voltages. Hot tungsten wires emit electrons back into the ambient plasma. Air drag sets EDDE's minimum altitude of 300-400 km. There is no hard ceiling, but thrust decreases at high altitude, requiring use of longer and heavier vehicles for efficient thrusting. In general, short electrodynamic thrusters do not perform well, since thrust scales with the product of current and length. Large electron collection areas are needed. Making the collector also serve as a long conductor makes it far more effective. This paper describes EDDE’s design, components, and operations, and some options for stowing and delivering multiple secondary payloads. The most attractive thing about EDDE to the smallsat world may be the possibility of “custom orbits without dedicated launch.”
Presentation Slides
EDDE: A Multi-Km Modular Upper Stage for SmallSats
"EDDE" (the ElectroDynamic Delivery Express) is a persistently maneuverable modular propellant-less vehicle for low earth orbit (LEO). EDDE has at least 2 major applications: payload delivery and debris removal. Vehicles as light as 20-30 kg can deliver secondary payloads to custom orbits, but 50-100 kg vehicles plus capture hardware are needed to efficiently remove orbital debris above 800 km. EDDE uses a reinforced aluminum foil tape to collect and conduct electrons, and solar arrays distributed along the length to limit peak local voltages. Hot tungsten wires emit electrons back into the ambient plasma. Air drag sets EDDE's minimum altitude of 300-400 km. There is no hard ceiling, but thrust decreases at high altitude, requiring use of longer and heavier vehicles for efficient thrusting. In general, short electrodynamic thrusters do not perform well, since thrust scales with the product of current and length. Large electron collection areas are needed. Making the collector also serve as a long conductor makes it far more effective. This paper describes EDDE’s design, components, and operations, and some options for stowing and delivering multiple secondary payloads. The most attractive thing about EDDE to the smallsat world may be the possibility of “custom orbits without dedicated launch.”
