This lecture provides an in-depth analysis of chemical propulsion systems, focusing on their various types, including monopropellant and bipropellant systems. The instructor begins by discussing the fundamental principles of thrust generation, emphasizing the importance of mass flow rate and exhaust velocity. The lecture covers the characteristics of different propellant phases, including solid, liquid, and gas, and their respective chemical reactions. The instructor explains the significance of thrust efficiency and how it relates to vehicle mass and propellant consumption. The discussion extends to the practical applications of these systems, particularly in space missions, highlighting the challenges and considerations in selecting appropriate propellants. The lecture also addresses the environmental impact of propulsion systems and the ongoing efforts to develop greener alternatives. Throughout the session, the instructor engages with students, encouraging questions and clarifications on complex topics, ensuring a comprehensive understanding of chemical propulsion systems and their operational dynamics.