History of SpaceX rocket engines in Timeline

SpaceX has developed several rocket engine families since its founding. These include the Merlin, Kestrel, Draco, and SuperDraco engines, used on Falcon family rockets and the Dragon spacecraft. More recently, SpaceX developed the Raptor engine, a methane-fueled engine intended for the Starship program. After 2020, a line of methalox thrusters was also created. These engines represent SpaceX's commitment to innovation in propulsion technology, with a focus on reusability and performance.

2002: SpaceX Founded

In 2002, SpaceX was founded and began developing rocket engines.

2003: Merlin 1 Engine Family Development Begins

In 2003, SpaceX began developing the Merlin 1 family of LOX/RP-1 rocket engines.

2006: Kestrel Engine Used on Falcon 1

From 2006, the Kestrel engine was developed by SpaceX as the Falcon 1 rocket's second stage main engine.

2006: Falcon 1 First Flight Powered by Merlin 1A

In 2006, the Merlin 1A engine, producing 340 kilonewtons of thrust, powered the first stage of the first Falcon 1 flight.

2007: Falcon 1 Second Flight Powered by Merlin 1A

In 2007, the Merlin 1A engine powered the first stage of the second Falcon 1 flight.

2007: Merlin 1C Full Mission Duty Firing

In 2007, the Merlin 1C engine was first fired with a full mission duty firing.

August 2008: Merlin 1C Flies on Falcon 1

In August 2008, the Merlin 1C engine first flew on the third Falcon 1 mission.

September 2008: Falcon 1 Reaches Orbit

In September 2008, Falcon 1 Flight 4, powered by Merlin 1C, became the first privately-developed liquid-fueled rocket to successfully reach orbit.

2009: Raptor Engine Concept Development Begins

In 2009, SpaceX began concept development work on the Raptor engine, initially studying an LH2/LOX propellant mix.

2009: Kestrel Engine Used on Falcon 1 through 2009

The Kestrel engine was used as the Falcon 1 rocket's second stage main engine through 2009.

2010: Merlin 1C Powers Falcon 9 Flights

From 2010, the Merlin 1C engine powered the first five Falcon 9 flights, each using a version 1.0 Falcon 9 launch vehicle.

2011: Merlin 1D Development Begins

The Merlin 1D engine, featuring a regeneratively-cooled nozzle and combustion chamber, began development in 2011.

October 2012: Engine Development and Use in Launch Vehicles

As of October 2012, Kestrel, Merlin 1, Draco, and Super Draco engines were developed for use in SpaceX launch vehicles like Falcon 1, Falcon 9, Falcon Heavy, and the Dragon capsule.

November 2012: Methane Engine Development Announced

In November 2012, SpaceX announced a new direction focusing on methane/LOX rocket engines to support their Mars technology development program.

2012: Merlin 1 Engine Family Development Concludes

In 2012, development concludes on the Merlin 1 family of LOX/RP-1 rocket engines.

2012: Merlin 1D Development Continues

The Merlin 1D engine development continues in 2012, featuring a regeneratively-cooled nozzle and combustion chamber.

September 29, 2013: Maiden Flight of Merlin 1D and Falcon 9 v1.1

On September 29, 2013, the Falcon 9 Flight 6 mission successfully launched the Canadian Space Agency's CASSIOPE satellite into polar orbit, marking the maiden flight of the Merlin 1D engine and Falcon 9 v1.1. The engine also demonstrated restart capability for controlled first-stage re-entry.

October 2013: Methane-Based Raptor Engine Family Announced

In October 2013, SpaceX announced plans to build a family of methane-based Raptor rocket engines, initially targeting 2.94 meganewtons of vacuum thrust.

2013: Merlin 1C Powers Falcon 9 Flights Through 2013

The Merlin 1C engine powered Falcon 9 flights from 2010 through 2013, each using a version 1.0 Falcon 9 launch vehicle.

2013: Kerosene-Based Engine Development

Through 2013, SpaceX developed two kerosene-based engines, the Merlin 1 and Kestrel, and discussed a larger concept engine design named Merlin 2. Merlin 1 powered the Falcon 1 first stage and is used on both stages of the Falcon 9 and Falcon Heavy, while the Kestrel powered the Falcon 1 second stage.

February 2014: Raptor Engine Selected for Mars Colonial Transporter

In February 2014, it was announced that the Raptor engine would be used on the Mars Colonial Transporter, with multiple engines on the booster.

February 2014: Raptor Preliminary Designs

As of February 2014, preliminary designs of the Raptor methane/LOX engine aimed for 4.4 meganewtons of thrust with a vacuum specific impulse of 363 seconds and a sea-level Isp of 321 seconds, though later designs considered sizes closer to 2.2 MN.

March 2014: Raptor Development Focuses on Large Engine

In March 2014, SpaceX confirmed that all Raptor development work was focused on a single, very large rocket engine, with no smaller Raptor engines in the current development mix.

May 2014: Raptor Component-Level Testing Begins

In May 2014, SpaceX initiated component-level testing of Raptor technology, starting with an injector element test.

2015: Nine Rocket Engine Architectures Developed

By mid-2015, SpaceX had developed a total of 9 rocket engine architectures in the first 13 years of the company's existence.

September 2016: First Complete Raptor Engine Testing

In September 2016, testing began on a ground test stand for the first complete Raptor development engine, approximately one-third the size of the full-scale engines, with around 1,000 kN of thrust.

September 27, 2016: Interplanetary Transport System Announcement

On September 27, 2016, Elon Musk announced the Interplanetary Transport System (ITS), later renamed Starship, at the 67th International Astronautical Congress, stating that all reaction control system thrusters would operate from gaseous methane and oxygen.

2016: Full-Flow Staged Combustion Cycle

By 2016, the Raptor engine was designed around a full-flow staged combustion cycle, sending 100% of the oxidizer (low-fuel ratio) to power the oxygen turbine pump and 100% of the fuel (low-oxygen ratio) to power the methane turbine pump, with both streams being fully gas phase before combustion. Only two other engines had undergone testing using this methodology.

2016: Raptor Methane Rocket Engine Development

In 2016, SpaceX began developing the Raptor methane rocket engine.

November 7, 2018: Falcon 9 Second Stage Upgrade

On November 7, 2018, Elon Musk tweeted that the Falcon 9 second stage would be upgraded to be like a mini-BFR Ship, potentially implying the use of a Raptor engine.

2020: Methalox Thruster Line Development

After 2020, SpaceX started developing a line of methalox thrusters.

2020: Methox RCS Thrusters on Starship HLS

By 2020, high-thrust methox RCS thrusters were planned for mid-body placement on the Starship HLS lunar-landing variant, to be used during the final meters of lunar descent and landing, as well as for lunar departure. The mid-body design aimed to mitigate lunar surface erosion and dust creation from Raptor engines located at the base of Starship.