Rockets work by expelling gas at high speeds from "summary" of Rocket Science: A Beginner's Guide to the Fundamentals of Spaceflight by Andrew Rader
Rocket propulsion is a fundamental concept in spaceflight, allowing spacecraft to overcome the forces of gravity and travel through the vacuum of space. At the heart of rocket propulsion is the principle of Newton's third law of motion: for every action, there is an equal and opposite reaction. In the case of rockets, this means that by expelling gas at high speeds in one direction, the rocket is propelled in the opposite direction. The process of expelling gas at high speeds to generate thrust is known as propulsion. Rockets achieve this by burning a propellant, such as liquid fuel or solid propellant, in a combustion chamber. The burning propellant produces hot gases that are expelled through a nozzle at the back of the rocket. As the gases are expelled at high speeds, they generate a reactive force that propels the rocket forward. The efficiency of a rocket engine is determined by the speed at which it can expel gas, known as the exhaust velocity. Higher exhaust velocities result in greater thrust and more efficient propulsion. Rocket engines are designed to maximize exhaust velocity by carefully controlling the combustion process and the shape of the nozzle. The concept of expelling gas at high speeds to generate thrust is not limited to chemical rockets. Other types of propulsion systems, such as ion thrusters and nuclear thermal rockets, also rely on the same principle. These advanced propulsion systems offer higher exhaust velocities and greater efficiency than traditional chemical rockets, making them ideal for long-duration space missions.- The concept of rockets expelling gas at high speeds to generate thrust is a fundamental principle of rocket propulsion. By harnessing this principle, spacecraft are able to overcome the forces of gravity and travel through the vacuum of space. Whether using traditional chemical rockets or advanced propulsion systems, the basic idea remains the same: propel gas in one direction to move the rocket in the opposite direction.
