Learning Objective: This is a discussion class. At the end of the session, the participants are expected to be able to develop conversational skills.


The study of rockets is an excellent way for students to learn the basics of forces and the response of an object to external forces. In flight, a rocket is subjected to the forces of weight, thrust, and aerodynamics. On this slide, we have removed the outer "skin" so that we can see the parts that make a rocket. There are many parts that make up a rocket. For design and analysis, engineers group parts which have the same function into systems. There are four major systems in a full scale rocket; the structural system, the payload system, the guidance system, and the propulsion system. On the figure we show a generic launcher, although launchers come in a wide variety of shapes and sizes. The launcher has a base to support the rocket during launch. A hollow launch tube is mounted perpendicular to the base and is inserted into the base of the rocket before launch. The launch tube is connected to an air pump by a hollow feeder line. The pump is used to pressurize the inside of the body tube to provide thrust for the rocket. We have attached a pressure gage to the feeder line to display the change in pressure in the system. For many air rockets, the pump is simply a cylinder which can be collapsed by striking with your hand or foot, which is where the "stomp" rocket got its name. In our simulation, we are going to pump up the system, and then launch the rocket, to better control and explain how the system works. On this page we show the events in the flight of a compressed air rocket. Air rockets are among the simplest type of rocket that a student encounters. The rocket consists of a hollow tube, with a nose cone on one end and stablizing fins at the other end. On the figure we show a generic launcher, although launchers come in a wide variety of shapes and sizes. The launcher has a base to support the rocket during launch. A hollow launch tube is mounted perpendicular to the base and is inserted into the base of the rocket before launch. The launch tube is connected to an air pump by a hollow feeder line. The pump is used to pressurize the inside of the body tube to provide thrust for the rocket. We have attached a pressure gage to the feeder line to display the change in pressure in the system. This part of the system is very similar to the simple compressed air rocket. On this page we show the events in the flight of a water rocket. Water rockets are among the simplest type of rocket that a student encounters. The body of the rocket is an empty, plastic, two-liter soda bottle. Cardboard or balsa fins are attached to the bottom of the bottle for stability, and a fairing and nose cone are added to the top as a payload. The standard bottle rocket uses a two liter soda bottle as the frame of the rocket, and pressurized water as the propellant. The whoosh rocket replaces the heavy water with a much lighter, combustible, alcohol-air mixture. The pressurization of the bottle occurs during the combustion of the alcohol. Because the exhaust products are much lighter than water, the whoosh rocket does not generate as much thrust as a water rocket, and the flight trajectory more closely resembles a ballistic flight than a water rocket trajectory. Although the whoosh rocket does not normally fly higher than 50 feet, it is instructional for students because the thrust is generated by the combustion of a liquid fuel.