System Requirements and Technical Challenges for a Very Low Perigee Satellite; A Comprehensive Design Study

Abstract

The results of a DLR feasibility study concerning a very low perigee satellite shall be presented in this paper. The study team (12 Engineers) used the Concurrent Engineering Facility of the DLR Institute in Bremen. The objective of this study was to design a consistent satellite that fulfills the mission objectives. This is only possible by considering all relevant subsystems, i.e. power system, thermal control, structure analysis and propulsion module. The satellite’s task is to perform in-situ measurements in the lower thermosphere. It is therefore supposed to dip deep into the atmosphere (130km x 800km). The paper starts with a short presentation of the Institute’s Concurrent Engineering facility and its capabilities. It then describes the mission objectives of the satellite and the imposed programmatic constraints. The envisaged instruments and their special requirements are assessed and the mission and system requirements are then derived and discussed. In its second part, the paper starts with highlighting the main obstacle for such a mission, the atmospheric drag and its influence on the design of such a satellite. The mission analysis will then be discussed in detail and the subsystems of the satellite bus that are most affected by this peculiar mission scenario will then be presented. The mass and power budgets will be presented for each subsystem. Given a limited amount of fuel several mission scenarios are possible. Two of them will be presented that enhance mission flexibility and extend nominal operation time. This part ends with the identification of the technological and physical challenges that constrain such a mission. Based on the first and second part, the challenges and benefits of such a mission will be discussed in the context of cost, TRL and uncertainties.