Merlin 1г—1 -

: The current active version, introduced in 2013. It is designed for rapid reusability and vertical landings. Core Specifications (Merlin 1D) Sea Level (SL) Vacuum (Vac) Thrust ~845 kN (190,000 lbf) ~981 kN (220,500 lbf) Specific Impulse (Isp) Chamber Pressure 9.7 MPa (1,410 psi) 9.7 MPa (1,410 psi) Thrust-to-Weight Ratio Sources: Design Innovations

: The initial version used an expendable ablatively cooled carbon-fiber nozzle. It flew only twice on the Falcon 1 (2006–2007). Merlin 1Г—1

: Uses a triple-redundant flight computer system on each engine to ensure high reliability during launch. : The current active version, introduced in 2013

: Drives both the LOX and RP-1 impellers. It also provides high-pressure fuel for hydraulic actuators , eliminating separate hydraulic systems. It flew only twice on the Falcon 1 (2006–2007)

: 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 consists of high-performance liquid rocket engines developed by SpaceX to power their Falcon 1 , Falcon 9, and Falcon Heavy rockets. Operating on a gas-generator open-cycle using RP-1 (rocket-grade kerosene) and liquid oxygen (LOX), they are renowned for their world-leading thrust-to-weight ratio and design for reusability. Key Variants and History

: One center Merlin engine is fired during the final landing burn to enable first-stage vertical landings.