High precision orbit simulations for geodesy and fundamental physics missions

Orbit propagation including detailed environment models as well as system models is the basis for generating mock data sets for developing appropriate data analysis procedures in case of scientific and geodesy space missions. They allow to determine in virtual space the sensitivity of involved instruments and, furthermore, they help to optimize mission scenarios before their final design. It has been shown that the best gravitational redshift test is only possible if the correct modeling of the solar radiation pressure as well as interactions with magnetic fields and temperature effects are included in the data analysis process. Additionally, high precision simulations allow for the calibration of instruments in preparation for data analysis procedures, e.g. accelerometers on board of the GRACE satellites. The HPS (Hybrid Simulation Platform for Space Systems) developed from DLR and ZARM, University of Bremen, deals with all of these aspects. As a modular and generic tool it can be adapted to various scenarios of mission concepts and layouts. This talk will present examples of the usage of HPS in the context of instrument calibration, orbit propagation for studying the environmental influences on the satellite's orbit, and data analysis improvement on behalf of mock data sets