SpaceX · Starship · 27 Oct 2026
SpaceX’s Raptor engines, explained: from 185 tons to Raptor 4’s 300
Raptor 4 will make 300 metric tons of thrust at sea level at roughly the same mass as Raptor 3, Elon Musk said on 26 Oct 2026. That’s 62% more than the first Raptor, from an engine that weighs about as much as a family car. Here’s how SpaceX got from Raptor 1 to Raptor 3, what Musk says Raptor 4 will add, and why it all matters for Mars (figures as of 27 Oct 2026).
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On 26 Oct 2026, at 9:58am ET (6:58am PT; ), Musk replied to a post on X with the next number for SpaceX’s engine: “Raptor 4 will be 300 tons of thrust at sea level and hopefully about the same mass.” Raptor 4 exists only in that sentence for now. SpaceX hasn’t shown the engine, and there is no Raptor 4 footage.
Three hours later he added a caveat about the engine that flies today. Raptor 3 is rated at 280 tons, but “We can only reliably get to around 230 t-F with Raptor 3,” he wrote at 1:13pm ET (10:13am PT; ). Both numbers matter, and the gap between them is part of this story.
The film
We cut a three-minute film from SpaceX’s and Musk’s own footage. It opens with Musk on Raptor 3, then runs through the first Raptor firings in 2019, the Starhopper flight, Raptor 2 on the test stand, Raptor 3’s debut, and 33 engines lifting Super Heavy. It ends with Raptor 4 as Musk’s words on screen, because that’s all there is of it.
The cycle nobody had flown
Raptor runs a full-flow staged combustion cycle. In plain terms, every drop of propellant passes through a turbine before it burns.
- Two preburners. An oxygen-rich preburner spins the oxygen pump. A methane-rich preburner spins the fuel pump.
- Nothing wasted. Both hot gas streams then meet and burn completely in the main chamber.
- The payoff. More gas through the turbines means higher chamber pressure and cooler turbines. And because each turbine runs on gas that matches its own pump, there’s no shared seal between fuel and oxidizer to fail. The U.S. Air Force Research Laboratory set out the same advantages when it tested the cycle.
Before Raptor, two programs had tried it. The Soviet RD-270 was built and test-fired in the 1960s, and the U.S. Integrated Powerhead Demonstrator ran on a NASA test stand in the 2000s. Neither ever left the ground. Raptor first flew on SpaceX’s Starhopper in 2019, and it’s still the only full-flow engine to have flown (as of 27 Oct 2026).
Squeezing the chamber
Chamber pressure is the cleanest way to track Raptor’s progress. Higher pressure lets a smaller engine push harder. Here are the milestones Musk has announced:
- February 2019: 268.9 bar. Musk said Raptor “reached 268.9 bar”, beating the record held for decades by Russia’s RD-180 (Aerospace Testing International).
- By January 2022: 300 bar. “Raptor 2 now operates routinely at 300 bar,” Musk said.
- May 2023: 350 bar. A Raptor 3 test engine “just achieved 350 bar chamber pressure (269 tons of thrust).” Musk said the team did not expect the engine to survive a full-duration run at that pressure, and that the chamber wall might have “the highest heat flux of anything ever made.”
Heat flux is the problem that comes with the pressure. Raptor survives it with regenerative cooling: cold methane flows through channels in the chamber and nozzle walls before it’s burned, so the fuel carries the heat away and the engine doesn’t melt itself.
Three generations, side by side
In August 2024, SpaceX published data cards for all three engines (Raptor 1 and 2; Raptor 3). “Installed” mass adds the vehicle-side hardware each engine needs on the rocket. These are SpaceX’s ratings (as of 27 Oct 2026):
| Engine | Rated thrust | Engine mass | Installed mass | Thrust to weight* |
|---|---|---|---|---|
| Raptor 1 | 185 t | 2,080 kg | 3,630 kg | ~89 |
| Raptor 2 | 230 t | 1,630 kg | 2,875 kg | ~141 |
| Raptor 3 | 280 t | 1,525 kg | 1,720 kg | ~184 |
| Raptor 4 (target) | 300 t | About Raptor 3’s† | — | — |
*Rated thrust divided by engine mass, our arithmetic; it’s a paper figure, not a flight measurement. Thrust is metric tons-force at sea level. †Raptor 4 row: Musk, 26 Oct 2026, “hopefully about the same mass”; SpaceX hasn’t published its other figures.
Read the rows top to bottom and two lines cross. From Raptor 1 to Raptor 3, installed mass fell 53% while rated thrust rose 51%. Thrust-to-weight roughly doubled, from about 89 to 184 on paper.
How SpaceX deleted the heat shield
Raptor 2 was a tangle of pipes and wiring on the outside. On Super Heavy, that meant each engine needed a heat shield and a fire-suppression system around it.
For Raptor 3, SpaceX moved the plumbing inside. It pulled pipes, wiring and secondary flow paths into the engine body and added regenerative cooling to the surfaces left exposed (Aviation Week). NASASpaceflight noted that the high-pressure side of the engine lost its bolted flanges and seals in favor of integrated parts.
Much of that internal plumbing only exists because of 3D metal printing. Musk says SpaceX has “the most advanced 3D metal printing technology in the world” (Metal AM). He called the work “staggering”: “The amount of work required to simplify the Raptor engine, internalize secondary flow paths and add regenerative cooling for exposed components was staggering.” As a result, he said, Raptor 3 needs no heat shield and no fire-suppression system (Tesla Oracle).
The scale shows up in the table. Installed mass fell by about 1.15 tons per engine from Raptor 2 to Raptor 3. Across a 33-engine Super Heavy booster that’s roughly 38 tons, our arithmetic from SpaceX’s figures.
Paper versus reality
The 280-ton figure is SpaceX’s rating. Musk’s 26 Oct reply gives the working number for today: “We can only reliably get to around 230 t-F with Raptor 3.”
- At 230 tons, 33 engines give Super Heavy about 7,600 tons of liftoff thrust (as of 26 Oct 2026, our arithmetic).
- That means reliable Raptor 3 output today roughly matches Raptor 2’s rating.
- But it does so with about 1.15 tons less installed mass per engine and no heat shield. The weight savings are real even before the thrust catches up.
Raptor 4: 300 tons
Raptor 4 will be 300 tons of thrust at sea level and hopefully about the same mass
— Elon Musk (@elonmusk) October 26, 2026
Musk’s target is 300 tons at sea level, “and hopefully about the same mass” as Raptor 3 (as of 26 Oct 2026). Against SpaceX’s own ratings, that’s:
- 62% more than Raptor 1’s 185 tons
- 30% more than Raptor 2’s 230 tons
- 7% more than Raptor 3’s 280-ton rating
Those percentages match a comparison posted by @niccruzpatane, and we re-checked the math. The bigger jump is over what Raptor 3 reliably does today: 300 tons would be about 30% above Musk’s 230.
Cost is the other half of the pitch. In November 2025, Musk said Raptor 3 should be 2 to 4 times better than Merlin, the Falcon 9 engine, on cost per ton of thrust, and that Raptor 4 should beat Merlin by more than 10 times. He also expects further gains in thrust-to-weight and efficiency. SpaceX hasn’t given a date for Raptor 4 or published a spec sheet.
Why methane matters for Mars
Raptor burns liquid methane and liquid oxygen, and that choice is about the trip home. Methane can be made on Mars from carbon dioxide in the air and hydrogen from water ice, using the Sabatier reaction. A Starship that lands there could refuel for the return without hauling all of that propellant from Earth.
Size matters too. Small, dense engines are what let Super Heavy fit 33 of them under a 9-meter (about 30-foot) base.
The Saturn V comparison
The Saturn V’s five F-1 engines made about 7.5 million pounds of thrust, roughly 3,400 metric tons, at liftoff (NASA).
If Super Heavy flew 33 Raptor 4s at 300 tons each, it would make about 9,900 tons. That’s nearly three times the Moon rocket that defined Apollo. It’s a target, not a test result (as of 27 Oct 2026): today’s reliable figure is about 7,600 tons, which is already more than twice Saturn V.
Sources: Elon Musk on X (26 Oct 2026, Raptor 4); Elon Musk on X (26 Oct 2026, “reliably ~230 t”); @niccruzpatane on X (26 Oct 2026); Elon Musk on X (3 Nov 2025, Merlin cost); SpaceX on X (Raptor 1 and 2 data card, Aug 2024); SpaceX on X (Raptor 3 data card, Aug 2024); Elon Musk on X (13 May 2023); Elon Musk on X (Jan 2022); Phys.org (12 Feb 2019); Aerospace Testing International (Feb 2019); NASASpaceflight (9 Aug 2024); Aviation Week; Metal AM (Aug 2024); Tesla Oracle (8 Aug 2024); Air Force Research Laboratory; Hackaday (13 Feb 2019); SpaceX on X (Starhopper, Aug 2019); NASA. Thrust-to-weight, percentage changes and 33-engine totals are Supercharged Daily’s own arithmetic from these figures. Film and hero photo: SpaceX (@SpaceX) and Elon Musk (@elonmusk); footage used editorially.
— Alex R
