SpaceX Raptor
The Raptor is a family of full-flow staged-combustion-cycle rocket engines developed and manufactured by SpaceX for use on the SpaceX Starship. The engine is powered by cryogenic liquid methane and liquid oxygen ("methalox"), as opposed to the RP-1 and liquid oxygen ("kerolox") combination used in SpaceX's earlier Merlin and Kestrel rocket engines. The Raptor engine has about triple the thrust of SpaceX's Merlin 1D engine, which powers the Falcon 9 and Falcon Heavy launch vehicles.
A Raptor 1 rocket engine ready for transport outside SpaceX's factory in Hawthorne, California | |
| Country of origin | United States |
|---|---|
| Manufacturer | SpaceX |
| Status | Currently in use |
| Liquid-fuel engine | |
| Propellant | LOX / CH4 |
| Mixture ratio | 3.6 (78% O2, 22% CH4) |
| Cycle | Full-flow staged combustion |
| Pumps | 2 turbopumps |
| Configuration | |
| Chamber | 1 |
| Nozzle ratio |
|
| Performance | |
| Thrust | Raptor 1: 185 tf (1.81 MN; 408,000 lbf) Raptor 2:
Raptor 3: 269 tf (2.64 MN; 593,000 lbf) |
| Throttle range | 40–100% |
| Thrust-to-weight ratio | 143.8, sea-level |
| Chamber pressure |
|
| Specific impulse, vacuum | 363 s (3.56 km/s) |
| Specific impulse, sea-level | 327 s (3.21 km/s) |
| Mass flow |
|
| Burn time | N/A |
| Dimensions | |
| Length | 3.1 m (10 ft) |
| Diameter | 1.3 m (4 ft 3 in) |
| Dry weight | 1,600 kg (3,500 lb) |
| Used in | |
| SpaceX Starship | |
SpaceX's Starship system uses Raptor engines in its super-heavy-lift Super Heavy booster and in the Starship spacecraft, which is to act as the second stage when launched from Earth and as an independent spacecraft in LEO and beyond. Starship is currently planned to be used for lifting satellites to Earth orbit, including additions to SpaceX's Starlink satellite constellation; for Moon landings, and in the exploration and colonization of Mars. Unlike the RS-25, the engines are designed to be reused many times with little maintenance.
Raptor is notable for being only the third rocket engine in history to be designed to use a full-flow staged-combustion-cycle, and the first of its kind to power a vehicle in flight.
Liquid methane and oxygen propellants, as used by the Raptor engine, are being adopted by many different companies in the 21st century, such as Blue Origin with its BE-4 engine, as well as the Longyun-70 engine being developed by Chinese startup Space Epoch for a rocket that has been described as a ‘mini Starship’ due to its similarities to the SpaceX Starship. There is also the Zhuque-2 rocket of LandSpace, which in July 2023 was the first methane fueled launch vehicle to reach orbit.