Riding Rockets

 

- Rebecca Boyle

 

What Is a Rocket?

Modern spaceflight began when the Chinese invented rockets about 800 years ago. Early rockets were like big fireworks—tubes filled with gunpowder, shot into the air over battles to frighten the enemy.

A rocket works by burning enormous amounts of fuel very quickly. As the fuel burns, hot gas shoots out one end, pushing the rocket tube in the opposite direction.

Eventually, some engineers began to wonder: if a rocket could travel a mile or more across the ground, could you shoot one straight up and get to space?

So You Want to Leave Earth

To escape the pull of Earth’s gravity and get into space, a rocket has to reach a speed of 25,000 miles (40,000 km) per hour—while pushing through a thick layer of air. That takes a lot of energy!

Talk Like a Rocket Scientist

Speed: How fast you are going.

Velocity: How fast you are going in one direction (speed +direction).

In the 1920s, American rocket scientist Robert Goddard began experimenting with liquid rocket fuels instead of gunpowder. Liquid fuels give more bang per pound, so rockets could be lighter and go faster. Goddard also figured out how to steer rockets. And he suggested that multi-part rockets might be the way to reach space.