In the scope of the master's project which is documented with the present thesis a mission planning tool (MPT) for SONATE was developed and implemented. After a thorough research on the current state of the art of MPTs and taking especially the early stage of the SONATE mission into account, it was decided to develop a generic timeline-based MPT. In contrast to existing MPTs a system is envisioned which is both powerful, regarding advanced features like resource control, and applicable for small satellite missions regarding the overall complexity and the associated configuration and training effort. Although it was obvious from an early stage that this vision cannot be reached in the scope of this project, it was kept during the project definition, object oriented analysis and early design stages in order to allow future extensions. Also the decision to develop the MPT on top of the Eclipse Rich Client Platform is mainly due to the argument of future extensibility. The MPT, which is released with this thesis, hence is a very basic generic timeline-based MPT omitting all possible advanced features like resource control or procedure validation, but featuring all essential parts of a MPT, i.e. modelling of procedures, scheduling of activities, and the generation of telecommand sequences. Furthermore, the user is supported by an intuitive graphical user interface. The thesis documents the development process, thus giving a broad understanding of the design and the implementation. For specific details of the implementation one may also refer to the separate technical documentation, while a user handbook included as appendix. The characteristics of the SONATE mission as a technology demonstrator for highly autonomous systems raise several important questions regarding the overall mission planning process. Therefore, besides the actual development of the MPT, those questions are discussed in a theoretical manner in the scope of this thesis, taking also account of the general emergence of highly autonomous satellites systems.Three concepts, Safe Planning, Sigma Resource Propagation, and Direct Telemetry Feedback, are proposed to face the challenges rising from the foreseen alternation of phases of classical mission operations and phases of autonomous operations of the satellite. Concluding the thesis, the final software product's features and capabilities are verified against the previously defined requirements and thus the overall success of the project is determined to be a 100% success fulfilling all primary project objectives. Finally, several fields for further research on the topic in general and work on the MPT itself are identified and outlined to pave the way for follow-up projects. / SONATE