Thrust is the force that propels the rocket.

Once ignited, a rocket engine pushes the hot gasses downwards. 

Isaac Newton said that for every action there is an opposite and equal reaction.

This means as the rocket motor gasses push down, the rocket is pushed up.

Unfortunately there are other considerations for the rocket to overcome:

  • GRAVITY - the Earth's gravity will try to pull the rocket back down
  • DRAG - As the rocket pushes up, the air resistance will try to stop it moving

Space Shuttle's engines, at lift-off, produced 37 million horsepower.
The average car produces 150 hp.

Apollo 8 Saturn V rocket launch