EDOARD: A tethered device for efficient Electrodynamic De-Orbiting of LEO spacecraft

EDOARD (Electrodynamic De-Orbiting And Re-entry Device) exploits the basic concepts of electrodynamic drag on conductive tethers to de-boost LEO spacecraft efficiently and reliably. The system is jointly developed by Alenia Spazio and the University “La Sapienza” in view of potential commercial exploitation. The technical design of the system will be completed by February 2001. The system is based on a short tether (4–5 Km length) and a large passive electron collector (up to 10 m diameter). The configuration ensures de-orbiting times per unit mass from a circular, 1500 km altitude, 55 degree inclination of about 0.09 day/kg (i.e., 6 months for 2000 kg spacecraft). For low inclination orbits the de-orbiting times are shorter by about a factor of three. The engineering design is driven by low mass (35 kg) and high reliability (0.95 minimum) requirements. The innovative approach has tackled four critical issues: 1) the deployment mechanism, which ensures a purely passive extension of the tether under extrem...