Mission Analysis and Trajectory Design for Space Rider Observer Cube

The work of this thesis focuses on two aspects of a 12U CubeSat mission: mission analysis and trajectory design and optimization. The project in question is Space Rider Observe Cube (SROC), an innovative ESA demonstration mission carried out by a CubeSat that will be deployed from Space Rider; the mission aims at demonstrating critical capabilities and technologies required to successfully execute a rendezvous and docking mission in a safety-sensitive context. Moreover, the project aims at demonstrating key technologies in the area of proximity operations, especially in the domain of in-orbit servicing, space exploration, and debris mitigation. The trajectory design and optimization are achieved by the update and the enhancement of a Matlab code, previously created by Politecnico di Torino, which interfaces the user with an STK scenario through the STK Object model software interface. The synergized use of the two software enables the Matlab function to iterate different possible trajectory solutions on Astrogator, STK’s tool for trajectory design. The relevant results and properties of these solutions are then saved by the Matlab function in dedicated structures or plotted in graphs to help the successive analysis and selection of an optimal Mission Control Sequence. This software analysis tool is used to set the optimal Mission Control Sequence for two ConOps for the SROC mission: the Observe and the Observe&Retrieve scenarios. Moreover, several deviations from the mission phases reported in the ConOps are analysed to assess how they affect the subsequent phases. For each of these possible deviations, it is then verified which respects the constraints on the total duration, total deltaV, and safety for Space Rider. The mission analysis part of the thesis focuses on the analysis of the illumination conditions and the ground station coverage during the mission. An acceptable Line of Sight angle is required during several phases of the mission since SROC hosts different sensors operating in the visible spectrum to perform its navigation functions and to take pictures of Space Rider when in its proximity. The ground station coverage is fundamental to guarantee the downlink of the mission data and to send the send commands to SROC; during some safety-critical phases, such as the Final Approach, it is fundamental to guarantee a sufficiently long window of GS visibility. Finally, several tools of the software DRAMA are described and used to evaluate the orbital lifetime of SROC (OSCAR tool), its re-entry survival prediction, and the associated on-ground risk for any object surviving the re-entry phase (SARA tool), and the deltaV cost to be allocated for the debris collision avoidance manoeuvres