1. Introduction 2. The Concept and History of Small Satellites 3. Comparing Platform paradigms: CubeSats vs. SmallSats 4. Evolving capabilities and limitations of future CubeSat missions 5. Legal Framework of Space Exploitation in the NewSpace Era 6. Ethical Insights Toward a Moral Assessment of CubeSats Technologies 7. Additive Manufacturing for CubeSat Structure Fabrication 8. Mechanisms 9. Introduction to CubeSat Power Systems 10. Attitude Determination and Control 11. Electro-Optical-based relative navigation 12. Control Architectures and Algorithms 13. Thermal Control Subsystem 14. Radio Frequency Telecommunication Systems for CubeSats and SmallSats 15. Optical Communication 16. Command and Data Handling Systems 17. Innovative and low-cost launch systems 18. Chemical and Cold Gas Propulsion Systems 19. Dual-mode propulsion systems for SmallSats 20. Electric propulsion systems 21. Propellant-less systems 22. Close Proximity Operations, Formation Flying, and On-Orbit Servicing 23. Overview of the New Space CubeSat market 24. Spectroscopy on CubeSats and SmallSats 25. Microbial biology on CubeSats 26. The STARS series of nanosatellite missions 27. The UVSQ-SAT mission 28. Future perspectives