DIRECT INJECTION INTO GEO - A NEW TREND IN LAUNCH SERVICES?

摘要

The classical commercial telecommunication satellites are aiming for the Geostationary Earth Orbit (GEO). Most of the available commercial launch vehicles place these satellites into Geostationary Transfer Orbit (GTO), where the satellite's propulsion system takes over to provide the final velocity increase to reach GEO. A direct insertion into GEO by the launch vehicle would add considerably to its competitiveness, offering a complete end-to-end service to the satellite operator. The study by Daimler-Benz Aerospace (Dasa) presented here is aiming at a dual-launch payload capacity of 4 tons. A representative architecture and mass budget of a modular transfer stage is presented. Transfer options are analysed with respect to minimum required thrust, orbit accuracy and timing. The constraints on orbital positioning from the dual-launch are analysed with their insertion strategies and satellite drift scenarios. Critical operational aspects as e.g extended mission duration, attitude and orbit determination are indicated. The paper shows possible advantages to the satellite, being reduced mass, technical complexity, operational effort and cost. A transfer stage for the direct launch into GEO is of interest also for other missions. The potential of the stage for Low Earth Orbit Manoeuvering is addressed .