Rockets
          
        
        
          
            277
          
        
        
          Around 300 tests were done.
        
        
          
            
              Saturn V
            
          
        
        
          were the largest
        
        
          rockets ever built. They were
        
        
          used to launch all the moon
        
        
          landings.
        
        
          
            Firework rockets
          
        
        
          are
        
        
          used for celebrations.
        
        
          
            Military rockets
          
        
        
          have
        
        
          been used for hundreds of
        
        
          years.
        
        
          
            Reusable space shuttles
          
        
        
          carry people to and from
        
        
          the space station.
        
        
          
            Types of rocket
          
        
        
          There are many
        
        
          different kinds of rocket.
        
        
          
            Experimental rockets
          
        
        
          provide information about
        
        
          fast and high flight.
        
        
          
            Some satellites
          
        
        
          have
        
        
          small rocket engines to
        
        
          position them once they
        
        
          are in orbit.
        
        
          Ariane 5
        
        
          launch vehicle. The main
        
        
          tank contains 25 tonnes (27.5 tons)
        
        
          of liquid hydrogen. The tubes on
        
        
          each side are solid fuel boosters that
        
        
          supply extra power for lift-off.
        
        
          
            Regular launches
          
        
        
          Today, rockets such
        
        
          as
        
        
          
            Ariane 5
          
        
        
          are used
        
        
          to launch satellites
        
        
          into space. A satellite
        
        
          is a rocket’s payload,
        
        
          or cargo, whose size
        
        
          determines whether it
        
        
          is sent up by a small or
        
        
          large rocket.
        
        
          
            Biggest and best
          
        
        
          The
        
        
          
            Saturn V
          
        
        
          were the largest, and most
        
        
          powerful, rockets ever built. They were used
        
        
          13 times, between 1968 and 1972, including for
        
        
          the first moon landing.
        
        
          
            Ariane 5
          
        
        
          To escape Earth’s
        
        
          gravity, a rocket
        
        
          has to reach
        
        
          just over 11 km
        
        
          (7 miles) per
        
        
          second. This is
        
        
          called the escape
        
        
          velocity.