History of SpaceX rocket engines in Timeline

SpaceX has developed several rocket engine families, each designed for specific purposes. Merlin engines are used for Falcon 9 and Falcon Heavy first and second stages, known for their reliability and reusability. Kestrel was used on Falcon 1 as a second-stage engine. The Draco and SuperDraco engines are hypergolic propellant-based thrusters for in-space maneuvering and the Dragon spacecraft's launch escape system, respectively. More recently, SpaceX developed the Raptor engine, a methane-fueled engine intended for Starship, focusing on high performance and full reusability, along with smaller methalox thrusters.

2002: SpaceX Founded

In 2002, SpaceX was founded and began development of rocket engines.

2003: Merlin 1 Engine Family Development

From 2003 to 2012, SpaceX developed the Merlin 1 family of LOX/RP-1 rocket engines.

2006: Kestrel Engine Usage

From 2006-2009, the Kestrel engine was used as the Falcon 1 rocket's second stage main engine.

2006: Merlin 1A Engine Flight

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

2007: Merlin 1A Engine Flight (Falcon 1)

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: First Flight of Merlin 1C

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

September 2008: Falcon 1 Flight 4 Success

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

2009: Kestrel Engine Usage

From 2006-2009, the Kestrel engine was used as the Falcon 1 rocket's second stage main engine.

2009: Raptor Engine Concept Origin

Since the late 2000s, SpaceX has been developing the Raptor engine family, originally considering LH2/LOX propellant, with the term "Raptor" initially referring to an upper stage engine concept in 2009.

2010: Merlin 1C Powers Falcon 9 Flights

From 2010 through 2013, the Merlin 1C engine powered the first five Falcon 9 flights, each using a version 1.0 launch vehicle.

2011: Merlin 1D Development

The Merlin 1D engine was developed in 2011–2012 featuring a regeneratively-cooled nozzle and combustion chamber, increased expansion ratio, and throttling capabilities.

October 2012: Engine Development for SpaceX Launch Vehicles

As of October 2012, Kestrel, Merlin 1, Draco and Super Draco engines had been developed for use in SpaceX's Falcon 1, Falcon 9, and Falcon Heavy launch vehicles, as well as the Dragon capsule. All main engines developed by this time were kerosene-based, using RP-1 fuel and liquid oxygen (LOX) oxidizer, while RCS control thrusters used storable hypergolic propellants.

November 2012: Methane/LOX Engine Development Direction

In November 2012, SpaceX CEO Elon Musk announced a new direction to develop methane/LOX rocket engines to support the company's Mars technology development program. There were no plans to build an upper stage engine for the Falcon 9 or Falcon Heavy using methalox propellant.

November 2012: Methane-Based Engine Development Announcement

In November 2012, SpaceX announced plans to develop methane-based engines for future rockets, utilizing staged cycle combustion for higher efficiency, similar to the Soviet Union's NK-33 engine.

2012: Merlin 1 Engine Family Development

From 2003 to 2012, SpaceX developed the Merlin 1 family of LOX/RP-1 rocket engines.

2012: Merlin 1D Development

The Merlin 1D engine was developed in 2011–2012 featuring a regeneratively-cooled nozzle and combustion chamber, increased expansion ratio, and throttling capabilities.

September 29, 2013: Falcon 9 Flight 6 Mission and Merlin 1D Flight

On September 29, 2013, the Falcon 9 Flight 6 mission successfully launched the Canadian Space Agency's CASSIOPE satellite into polar orbit. This flight also demonstrated the Merlin 1D engine's restart capability for controlling the first stage's re-entry, a step in SpaceX's reusable launch system flight test program.

October 2013: Methane-Based Raptor Engine Family Announcement

In October 2013, SpaceX announced its intention 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

From 2010 through 2013, the Merlin 1C engine powered the first five Falcon 9 flights, each using a version 1.0 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 first stage of the Falcon 1 and is used on both stages of the Falcon 9 and Falcon Heavy, while Kestrel powered the Falcon 1 second stage.

February 2014: Raptor Engine Use on Mars Colonial Transporter

In February 2014, SpaceX announced the Raptor engine would be used on the Mars Colonial Transporter, with the booster employing multiple engines similar to the Falcon 9.

February 2014: Raptor Engine Preliminary Designs

As of February 2014, Raptor preliminary designs aimed for 4.4 meganewtons of thrust with a vacuum specific impulse of 363 seconds and a sea-level Isp of 321 seconds, although later concept sizes were closer to 2.2 MN.

March 2014: Raptor Development Focus

In March 2014, SpaceX confirmed that all Raptor development work was focused exclusively on a single, very large rocket engine.

May 2014: Raptor Technology Component-Level Testing

In May 2014, SpaceX began initial 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 its first 13 years.

September 2016: First Complete Raptor Development 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 planned for Starship, with approximately 1,000 kN thrust. The test nozzle had a low expansion ratio for atmospheric testing.

September 27, 2016: Interplanetary Transport System Announcement

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

2016: Raptor's Full-Flow Staged Combustion Cycle

Before 2016, only two full-flow staged combustion rocket engines had been tested on test stands: the Soviet RD-270 project in the 1960s and the Aerojet Rocketdyne Integrated powerhead demonstration project in the mid-2000s, which only tested the powerhead.

2016: Raptor Methane Rocket Engine Development

In 2016, SpaceX developed the Raptor methane rocket engine.

November 7, 2018: Falcon 9 Second Stage Upgrade Implication

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

2020: Methalox Thruster Line Development

After 2020, SpaceX developed a line of methalox thrusters.

2020: High-Thrust Methox RCS Thrusters for Lunar Landing

By 2020, high-thrust methox RCS thrusters were planned for the mid-body of the Starship HLS lunar-landing variant for final lunar descent and landing, as well as lunar surface departure, addressing lunar surface erosion from Raptor engines.