GeoSAR: Summary of the Group Design Project MSc in Astronautics and SpaceEngineering 2005/06 Cranfield University

摘要

Students of the MSc course in Astronautics and Space Engineering 2005/06 atCranfield University took GeoSAR as one of their group projects. This reportsummarises their findings. GeoSAR is an initial feasibility study for asatellite carrying a passive bistatic radar receiver based in geosynchronousorbit. The feasibility of the radar concept has already been established (e.g.through the work of Prati et al. of Politecnico di Milano) but no designs haveyet been published for a satellite to support the mission. This project developsan outline design of the spacecraft and confirms its feasibility within a(conservative) mass budget of approximately 300 kg. Mission drivers are theradar antenna diameter and the station-keeping propulsion required for a designlife of 15 years. Technologies such as inflatable structures and (field-emission) electric propulsion are used to reduce the spacecraft's mass. Anoutline cost estimate for the mission suggests that a GeoSAR mission would besignificantly cheaper than conventional low-Earth orbit radar satellites toachieve similar capability in terms of rapid-response imaging andinterferometry. In several areas the GeoSAR design is conservative and it isplausible that on further iterations of the design the cost and mass can bereduced. This suggests that among options for future Earth observation missions,GeoSAR deserves serious consideration.