This textbook is a compendium for further education of students and professionals in aerospace industry. It covers the fundamentals of aerospace and explains the details of technical implementations. These are organised in the border area of technical feasibility. The authors discuss constraints of space flight and key elements of rocket motors and power supply in more detail. The accessibility of the celestial bodies is tabulated and documented in the outlook chapter, in which the largest vision of space flight, humans to Mars, is explained. From the content: Historical Background Basic Principles Propulsion Systems Missions Energy Sources Materials and Lubricants Processes Products Projects and Payloads Launch Sites Environmental and Boundary Conditions Conclusions and Outlook Appendix with an extensive collection of formulas