How do rockets fly?

A rocket relies on high-pressure exhaust to propel it into the sky. It is a case of one of Isaac Newton's laws again—for every action there is an equal and opposite reaction. High-pressure exhaust gases blasting downward cause the rocket to blast upward—a blastoff! The burning of fuel (called combustion) makes the exhaust gases. Many different types of fuels are used in rockets. The most common fuels used by NASA are liquid oxygen and liquid hydrogen. These fuels are held in separate tanks located on the booster rocket. When mixed together, hydrogen and oxygen burn to produce enormous amounts of energy, as you have seen if you ever watched a launch from the Kennedy Space Center. The tremendous flames that shoot out the bottom of a rocket when the controller says "ignition" provide the energy to "blast off." Sometimes solid-rocket fuels are used instead of liquid ones, but the principle is the same—high-energy combustion of fuels launches a rocket into space. How Does a Spacecraft ...  more