Application of the propulsion subsystem on the base of SPT-100b plasmic thruster to the Express-80 and Express-103 spacecraft’s orbit raising and orbit control

Recently, there has been an increase of interest in satellite orbit raising using electric propulsion subsystems. Theoretic analyses and practical experience demonstrate that while orbit raising to GEO via a transfer orbit is feasible, it requires a certain amount of time due to electric thrusters’ thrust being low (40-300 mN) and thus incomparable with that of apogee propulsion systems’ liquid propellant thrusters (22-400 N). Due to low thrust, orbit raising by electric thrusters is time-consuming. However, the associated increase in mass to GEO may counterbalance the long duration of satellite commissioning. Calculations demonstrate a potential added satellite mass on GEO of up to several hundred kilograms with orbit raising duration of about 6 months. In particular, with satellite mass not exceeding 2500 kg, coupled launch is possible using existing launch vehicles. ISS took into consideration the positive results obtained with Express-AM5, and Express-AM6 satellites to design the Express-80 and Express-103 with orbit raising in mind. Such approach allowed for a coupled launch on Proton-M carrier rocked with Breeze-M upper stage, and a twofold launch cost saving. To increase thrust during orbit raising and decrease its duration, coupled thruster operation in high thrust mode was implemented. The resulting total mass on GEO increase constituted over 700 kilograms with maneuver duration of up to 158 days. This allows performing coupled launches of heavier satellites with orbit raising by means of electric propulsion in a feasible timeframe.