How does a rocket blast off?

Explosive chemical reactions are what send spacecraft into space. A rocket burns fuel to produce a jet of hot, expanding gas. What fuel is used varies, but whatever the mixture, it causes the explosive chemical reaction. Because a rocket needs thrust to escape Earth's gravity, the explosive chemical reaction takes place in a confined chamber and releases gases into a cone-shaped nozzle out the back end of the rocket. The cone-shape accelerates the gases and they blast out of the engine at up to 9,941 miles (15998 kilometers) per hour.