Mass savings domain of plasma propulsion for LEO to GEO transfer

A parametric model is used to study the mass savings of plasma propulsion over advanced chemical propulsion for lower-Earth-orbit to geosynchronous-Earth-orbit transfer. Such savings are characterized by stringent requirements of massive payloads [ϕ (10) metric tons] and high-power levels [ϕ (100) kW]. Mass savings on the order of the payload mass are possible but at the expense of longer transfer times (8-20 months). Typical of the savings domain is the case of a seif-field magnetoplasmadynamic (MPD) thruster running quasisteadily, at an I_s of 2000 s, with 600 kW of input power, raising a 50 metric ton satellite in 270 days. The initial mass at LEO will be 65 ton less than a 155 ton LO₂/LH₂ advanced chemical high thrust spacecraft. An optimum I_s can only be found if the cost savings associated with mass savings are counterbalanced by the cost losses incurred by longer transfer times. A simplistic cost model that illustrates the overall trends in the optimization yielded an optimum I_s of about 2200 s for a cost effective baseline MPD system.