Raptor is the methane-burning engine that powers both stages of SpaceX's Starship.
spacex-raptor SpaceX built Raptor to power both stages of Starship. It burns liquid methane with liquid oxygen. The Super Heavy booster carries 33 of them and the ship carries six: three for sea level and three for vacuum.
Raptor was the first full-flow staged combustion engine to power a vehicle in flight. Two preburners drive its turbines: one burns all the oxygen with a little methane, the other all the methane with a little oxygen. Elon Musk has said SpaceX developed its own superalloys, SX300 and SX500, for the hot oxygen-rich turbopump.
Raptor engines power SpaceX’s Super Heavy booster and Starship upper stage. Full-flow staged combustion puts hot, oxygen-rich gas through the turbopumps, which is why SpaceX developed special superalloys for them.
Each engine has two turbopumps, pumps spun by turbines, one for oxygen and one for methane. An oxygen-rich turbine drives the oxygen pump, and a fuel-rich turbine drives the methane pump. Torch igniters light the preburners.
On Raptor 2, coaxial swirl injectors admit the propellants to the main chamber. The nozzle is regeneratively cooled, so propellant flowing through its walls carries heat away. The vacuum version, RVac, has an extended nozzle for higher specific impulse in space, a measure of how efficiently an engine uses propellant.
SpaceX casts the engine manifold in its own foundry from Inconel, a heat-resistant superalloy. In 2018 posts, Elon Musk said the oxygen-rich turbopump's hot section uses SX300, with SX500 to follow, and called them something like a modern Inconel. SX500, he said, was made for hot, oxygen-rich gas at 12,000 psi.
SpaceX 3D printed many parts of early Raptor prototypes, including the turbopumps and injectors. By mass, 40 percent of a 2016 subscale engine was printed. Raptor 3 puts its sensors and controllers inside the engine's own thermal protection, and electric actuators swivel the engines in place of hydraulics.
The engine manifold, cast in SpaceX's own foundry. SpaceX does not give the exact alloy.
The hot section of the oxygen-rich turbopump. Elon Musk described them as a modern version of Inconel.
Raptor first flew in July 2019, on the Starhopper test vehicle. Raptor 2 is a complete redesign of the first Raptor, and Raptor 3 came after it. On Starship, Raptors lift the Super Heavy booster and the ship, and NASA says the Moon-lander version uses them too. SpaceX makes the engine itself.
SpaceX
33 Raptor engines on the Super Heavy booster
6 Raptor engines on the Starship upper stage (NASA text on the HLS ship); sea-level and vacuum split in the next row
3 of the 6 ship engines are Raptor Vacuum (RVac)
first flight of the engine on a vehicle, July 2019
Raptor 2 is a complete redesign of Raptor 1
NASA states that both the lander and the booster use SpaceX's Raptor engines
SpaceX has not published a materials list for Raptor. Only two metals are named, in posts by SpaceX's chief executive, and the make-up of SX300 and SX500 is not public. The chamber liner, injector, nozzle and pump casings are not described, and the published performance figures come from a 2019 analysis, not from Raptor 2 or 3.
What is written above is built from these numbers and quotes. Each row links to the page it was taken from. Get all of it as JSON, or ask our MCP server.
| What | Value |
|---|---|
| Propellants | Liquid oxygen and liquid methane |
| Chamber pressure (2019 baseline) | 3,669.5 psia |
| Mixture ratio (2019 baseline) | 3.60 |
| Nozzle area ratio (booster engine) | 34.34:1 |
| Engines on baseline booster (2019) | 31 |
| Boost-stage engine count (NASA) | 33 |
| Ship engine count (NASA) | 6 |
| First flight with all 33 engines lit | 18 November 2023 (second integrated flight test) |
| First fully stacked Super Heavy-Starship launch | 20 April 2023 |
| Raptor upgrades flown on the fourth integrated flight | 6 June 2024 |
| Lunar-landing throttle evaluation | tested under lunar landing throttle profiles |
| Raptor 1 target chamber pressure | 250 bar (25 MPa; 3,600 psi) |
| Raptor 3 sea-level engine mass | 1,525 kg (3,362 lb), down from 1,630 kg |
| Power cycle first | first full-flow staged combustion engine to power a vehicle in flight |
Each material named in the sources: where it is used here, which other products use it, and its key numbers when its material page exists.
Used in 1 partEngine manifold
Used in 1 partOxygen-rich turbopump hot section
Two parts (cast manifold, oxygen-rich turbopump hot section) have a stated material; both statements come from posts by SpaceX’s CEO as reported by a blog. Components, suppliers and links were added from public sources. A material is left blank where no source states it.
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Engine manifold“SpaceX foundry casting Raptor engine manifold out of Inconel” | Inconel (alloy not stated), castinconel | — | — |
| Oxygen-rich turbopump hot section“SX 300 & soon SX 500. Kind of a modern version of Inconel superalloys.” | SpaceX SX300 / SX500 superalloyspacex-sx500-superalloy | — | Reported by Musk (June 2018) for the oxygen-rich turbopump |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Regeneratively cooled thrust chamber nozzle“34.34:1 regeneratively-cooled thrust chamber nozzle” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Raptor sea-level engine (booster and ship)main engine of Super Heavy (33) and the ship (3)“Blocks 1 through 3 have three sea-level engines, as well as three engines optimized for operation in the vacuum of space, called RVacs.” | Not said | — | Supplier: SpaceX |
| Raptor Vacuum (RVac) engine, three on the shipvacuum-optimised version for in-space burns“with an extended, regeneratively-cooled nozzle for higher specific impulse in space” | Not said | — | Supplier: SpaceX |
| Raptor 2 (complete redesign of Raptor 1)second engine generation“Raptor 2 is a complete redesign of the Raptor 1 engine.” | Not said | — | — |
| Raptor 3third engine generation with lower mass and integrated electronics“with the sea-level engine mass reduced to 1,525 kg (3,362 lb) from 1630 kg” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Oxygen-rich preburnerburns all the oxygen with a little methane to drive the oxygen turbine“a twin-shaft staged combustion cycle that uses both oxidizer-rich and fuel-rich preburners” | Not said | — | — |
| Fuel-rich preburnerburns all the methane with a little oxygen to drive the methane turbine“a twin-shaft staged combustion cycle that uses both oxidizer-rich and fuel-rich preburners” | Not said | — | — |
| Oxygen turbopump (driven by an oxygen-rich turbine)pumps liquid oxygen to the preburner and main chamber“An oxygen-rich turbine powers an oxygen turbopump” | Not said | — | — |
| Methane turbopump (driven by a fuel-rich turbine)pumps liquid methane to the preburner and cooling jacket“a fuel-rich turbine powers a methane turbopump” | Not said | — | — |
| Torch igniters in the preburnerslight the preburners“Torch igniters are used in the preburners.” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Main injector (coaxial swirl elements)admits propellants into the main combustion chamber“Raptor 2 uses coaxial swirl injectors to admit propellants to the combustion chamber.” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Electronic thrust vector control systemgimbals engines with electric actuators instead of hydraulics“demonstrated faster ground propellant loading and an electronic thrust vector control (TVC) system” | Not said | — | — |
| Engine sensors and controllers inside the engine thermal protection (Raptor 3)integrated engine electronics“Raptor 3 integrates its sensors and controllers inside the engine's thermal protection.” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Additively manufactured parts and assemblies3D-printed engine hardware“incorporating additively manufactured parts and assemblies” | Not said | — | — |
| 3D-printed turbopumps and injectors (early prototypes)printed pump and injector components on early engines“Many components of early Raptor prototypes were manufactured using 3D printing, including turbopumps and injectors.” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Engine acceptance tests and spin-prime testsqualification of booster and ship engines before flight“SpaceX conducted a series of Raptor engine acceptance tests” | Not said | — | — |
| McGregor, Texas engine test facilitysite of the vacuum Raptor cold-start test“a vacuum Raptor cold-start demonstration test was completed at SpaceX’s McGregor, Tex. facility in August 2023” | Not said | — | — |
No primary-document materials list. Grades unknown (Inconel alloy, SX300/SX500 composition). Raptor 2 and Raptor 3 materials not covered. More detail: SpaceX has not published a Raptor bill of materials or an engine drawing; the turbopump casings, preburners, main chamber jacket, valves and igniter hardware have no stated alloys beyond the two in the current entry. FAA and NASA documents give vehicle-level engine counts but no part list. Raptor 2 and Raptor 3 chamber pressure, thrust and mass are Wikipedia statements citing SpaceX posts that could not be read (spacex.com update pages return no text). The Raptor 3 'integrated sensors and controllers' statement and the coaxial swirl injector statement are Wikipedia statements (the injector one cites an AIAA journal paper that was not opened). Autogenous pressurisation heat-exchanger, engine gimbal actuator and main valve hardware are not described in any readable primary source. Quotes from the NASA HLS papers and the NASA OIG report were machine-checked against the PDF text; Wikipedia quotes came through a text extractor and were not machine-checked. More detail: SpaceX has not published a Raptor bill of materials or an engine drawing; the turbopump casings, preburners, main chamber jacket, valves and igniter hardware have no stated alloys beyond the two in the current entry. FAA and NASA documents give vehicle-level engine counts but no part list. Raptor 2 and Raptor 3 chamber pressure, thrust and mass are Wikipedia statements citing SpaceX posts that could not be read (spacex.com update pages return no text). The Raptor 3 'integrated sensors and controllers' statement and the coaxial swirl injector statement are Wikipedia statements (the injector one cites an AIAA journal paper that was not opened). Autogenous pressurisation heat-exchanger, engine gimbal actuator and main valve hardware are not described in any readable primary source. Quotes from the NASA HLS papers and the NASA OIG report were machine-checked against the PDF text; Wikipedia quotes came through a text extractor and were re-checked in a second fetch pass but not against a saved copy of the page.
Collected from public pages and documents, checked 4 Nov 2026.
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