Propulsion

  There are many different types of rocket propulsion ranging from Chemical to Nuclear.  The output of the different propulsion systems are divided into different classes.  The basic estes rockets that have become very popular are solid motors.  Solid motors make up the bulk of rockets.  Liquid fueled rockets are much more dangerous to work on.  Hybrid rockets are a combination of both and are a newer method of propelling rockets.  Hybrids are gaining popularity.