Facts About Rockets
Although rockets have only been traveling to space since the mid-20th Century, rocket technology has existed since around the year 1200. Originally rockets were used as weapons and as celebratory fireworks.
A rocket needs two things to fly: fuel and an oxidizer. Mixed together these ingredients make rocket propellant, the stuff that burns in the rocket engine.
Rockets use Isaac Newton's third law of motion: For every action there is an equal and opposite reaction. The action is the engine pushing the rocket propellant away. The reaction is the rocket being pushed in the opposite direction (just like the recoil of a gun).
At liftoff, the heaviest part of a rocket is the propellant.
There are three types of rocket propellant: Liquid, solid and hybrid. They each have pros and cons. One rocket may be made up of separate stages that uses different types of propellant.
The first liquid-fueled rocket was launched by Robert Goddard in 1926. The rocket reached an altitude of 12 metres.
The first human-made object to be launched into space was a bomb. It was a V-2 rocket launched by Nazi Germany during World War II. It was not designed to go into orbit around Earth, just to go high and far enough to fall on England.
The first human-made object to orbit the Earth was Sputnik I, a small satellite launched by Soviet Russia 1957.
Many rocket manufacturers are moving towards re-usable rockets, which should reduce the cost and environmental impact significantly.