: An upgraded variant of the 1A with a more powerful turbine; it was never used on a flight vehicle before SpaceX shifted to regenerative cooling.
: Based on the Apollo Lunar Module landing engine, this provides excellent stability and allows for deep throttling. Merlin 1Г—1
: Uses a triple-redundant flight computer system on each engine to ensure high reliability during launch. : An upgraded variant of the 1A with
: Drives both the LOX and RP-1 impellers. It also provides high-pressure fuel for hydraulic actuators , eliminating separate hydraulic systems. : Drives both the LOX and RP-1 impellers
: The first to feature a regeneratively cooled nozzle and combustion chamber. It powered the first privately developed rocket to reach orbit (Falcon 1 Flight 4) and early Falcon 9 flights.
: The initial version used an expendable ablatively cooled carbon-fiber nozzle. It flew only twice on the Falcon 1 (2006–2007).