falcon 9 is a two-stage rocket. it was designed and manufactured by spacex in the united states. parts of the rocket can be used more than one time. the latest version of the first stage can return to earth and be flown again many times. both the first and second stages are powered by spacex merlin engines. they use cryogenic liquid oxygen and rocket-grade kerosene (rp-1) as fuel. its name comes from the fictional star wars spacecraft, the "millennium falcon". the 9 is for the nine engines of the rocket's first stage. there have been many versions of the rocket. these include v1.0 (2010–2013), v1.1 (2013–2016) and v1.2 full thrust (2015–present). it also includes the falcon 9 block 5 version.