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Stoke Space to build SpaceX Raptor engine’s first real competitor

Stoke Space has begun testing parts of an engine similar to SpaceX's famous Raptor.

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Seattle startup Stoke Space has revealed plans to develop an efficient rocket engine similar to the Raptors that power SpaceX’s Starship.

Formed in October 2019, Stoke Space secured its first significant round of funding – $9.1 million – less than three years ago. At that time, CEO and co-founder Andy Lapsa says that the startup had just five employees, no permanent workspace, and a “barren field” for a test site. Within 18 months, Stoke Space had turned that empty field into an impressive test facility, conducted numerous component tests, and assembled its first full-scale rocket engine – an exotic UFO-like device unlike any seen before.

It also raised another $65 million – enough funding to begin earnestly developing a potentially revolutionary rocket capable of launching more than 1.65 tons (~3600 lb) into orbit for less than half a million dollars. To realize that extremely ambitious goal, Stoke Space has taken the even more ambitious step of attempting to make the first rocket it develops fully reusable. Simultaneously, the company has incorporated several exotic technologies into that rocket, recently culminating in a surprise announcement that it will attempt to develop one of the most difficult types of engines to power that rocket’s booster stage.

Full-flow staged combustion

At the end of an extended interview and tour with YouTuber Tim Dodd (The Everyday Astronaut), CEO Andy Lapsa revealed that Stoke Space has decided to build a full-flow staged combustion (FFSC) engine for the first stage of its reusable rocket. FFSC is the most efficient type of combustion cycle available for a chemical bipropellant rocket engine, but it’s also the most difficult to develop.

A full-flow engine attempts to squeeze every possible ounce of performance out of the propellant it consumes. The most powerful and efficient chemical rocket engines must consume huge volumes of propellant in a short amount of time without destroying the launch vehicle they’re attached to. To create pressure and spin the pumps that are needed to feed that propellant into their main combustion chamber, engines often burn a small amount of propellant in a separate gas generator or preburner. Gas-generator engines vent that exhaust overboard, reducing efficiency but making for a much simpler design. Staged-combustion engines use preburners to create gas that pumps liquid propellant, and that exhaust gas is eventually injected into the main combustion chamber.

Full-flow staged combustion sets itself apart by having two separate pumps and preburners for oxidizer and fuel. Unlike simpler variants of staged combustion, FFSC engines turn all of their propellant into gas before injecting it into the combustion chamber. That hot gas increases the heat of combustion and the pressure inside the combustion chamber, ensuring that virtually all of the propellant that flows through the engine is combusted and turned into thrust as efficiently as possible. FFSC is exceptionally difficult because of the extra-high temperatures and pressures it requires, as well as the need for an oxygen-rich preburner and pump. In a high-pressure, hot-oxygen environment, virtually anything imaginable – including most metals – will spontaneously combust.

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Only complex custom-designed alloys can survive those conditions. SpaceX’s Raptor, the only FFSC engine that has ever flown, is especially difficult because it’s meant to be highly reusable. To be successful, Raptor will have to survive those conditions dozens or even hundreds of times in a row with little to no maintenance in between.

The first booster engine Stoke Space ever attempts to build will be a reusable full-flow staged combustion engine powered by liquid methane and liquid oxygen – essentially a smaller version of SpaceX’s Raptor. Stoke’s booster is otherwise familiar and features deployable landing legs like SpaceX’s Falcon boosters. Lapsa says it will likely also have grid fins.

Reusing the upper stage

In some ways, the upper stage of Stoke’s first rocket is even more ambitious. Powered by hydrogen and oxygen propellant, Stoke has designed a conical capsule-like upper stage with an integral fairing. The upper stage’s propulsion is exotic and unique. A large pump will feed propellant to up to 30 combustion chambers distributed around the rim of its heat shield. The exhaust coming from those 30 chambers will expand and partially push against the upper stage’s equally exotic metallic, liquid-cooled heat shield. That expansion against the heat shield improves the efficiency of the upper stage and means that its engine will technically be an aerospike.

Stoke has already begun testing a full-scale version of the upper stage’s UFO-like rocket engine with 15 combustion chambers. Since testing began in the second half of 2022, Stoke has completed dozens of static fires. Everyday Astronaut’s tour also revealed that the startup has made significant progress fabricating and assembling its first full-scale upper stage prototype – tanks, nosecone, heat shield, engine, and all.

Reminiscent of SpaceX’s Grasshopper and Starhopper campaigns, Stoke plans to conduct hop tests with that prototype if it makes it through qualification testing. On February 7th, Stoke also revealed that it’s begun testing a crucial component of its full-flow booster engine. All told, Stoke Space is making progress at a remarkable pace and continues to tackle the hardest problems. The startup has also avoided widely publicizing any specific deadlines, instead choosing to let hardware and tangible results speak for themselves. Only time will tell if that approach pays off, but Stoke is off to an exceptionally impressive start in an industry full of impressive rocket startups.

Eric Ralph is Teslarati's senior spaceflight reporter and has been covering the industry in some capacity for almost half a decade, largely spurred in 2016 by a trip to Mexico to watch Elon Musk reveal SpaceX's plans for Mars in person. Aside from spreading interest and excitement about spaceflight far and wide, his primary goal is to cover humanity's ongoing efforts to expand beyond Earth to the Moon, Mars, and elsewhere.

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Tesla’s flying Roadster just revealed something bigger than the car

Analysts say the Roadster demo puts a Tesla and SpaceX merger back on the table.

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Tesla’s new Roadster, upside down and trailing cold gas thruster smoke, flips over a lineup of Tesla vehicles at the Roadster unveiling near Waco, Texas on October 15, 2026. (Image: Tesla)
Tesla’s new Roadster, upside down and trailing cold gas thruster smoke, flips over a lineup of Tesla vehicles at the Roadster unveiling near Waco, Texas on October 15, 2026. (Image: Tesla)

The Roadster unveiling near Waco ended Thursday night, and by Friday morning much of the investor reaction had less to do with the car than with who owns the rocket technology inside it.

Wedbush analyst Dan Ives said the event “puts the Tesla/SpaceX relationship on the table in a tangible way,” pointing to the propulsion, pressure vessel and control hardware sitting on a Tesla product. Gene Munster of Deepwater Asset Management called the demo “a ridiculous display of engineering” with “no commercial value” beyond embarrassing traditional automakers, though he said it showed Musk wants the two companies together.

The more specific forecast came a day earlier from Barclays. Analyst Dan Levy told clients a deal could be announced before Tesla’s annual meeting, which must happen by December 6, and that an announcement in late October or early November could make shareholder approval harder. Barclays expects SpaceX to be the buyer in an all stock deal, with Tesla holders receiving SpaceX shares at a premium, based on market values of roughly $2.1 trillion for SpaceX and $1.5 trillion for Tesla. If nothing lands around the meeting, the bank still sees an announcement within 6 to 12 months.

The Roadster demo just added more weight to merger speculations. Tesla’s demo used cold gas thrusters and pressure tanks of the kind SpaceX uses on Falcon 9, and Musk described the car as a collaboration between Tesla and SpaceX engineers, as we mentioned in our breakdown of the three Roadster configurations.


Musk has not publicly addressed a deal since the event, as far as we have seen. His most direct answer remains the one he gave at the All In Summit, when he said that with so much collaboration, “who can imagine what action one might take” without ruling anything out. Ives has held to a 2027 timeline since his March note, and Musk pushed back on the China piece of the speculation when ARK floated a year end announcement in August.

The next test is Tesla’s third quarter earnings call on October 21. However, we recall in July that Musk told analysts, “we can’t talk about combining companies and that kind of thing on an earnings call,” so a clear answer wouldn’t be expected.

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How Tesla’s Roadster fan system and thrusters are built to dominate the corners

Tesla’s Roadster uses fans, active wings and cold gas thrusters to create grip at any speed.

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The Roadster’s rear wing, one of the aerodynamic elements Tesla pairs with a fan-based downforce system. (Image: Tesla)
The Roadster’s rear wing, one of the aerodynamic elements Tesla pairs with a fan-based downforce system. (Image: Tesla)

Tesla’s new Roadster is best known for flipping through the air in Texas, but the technology that matters most for a race track is the stuff that keeps it on the ground. Tesla’s Roadster page describes a multi-mode fan and ground sealing system that acts as a downforce generator, pulling air out from beneath the car. Tesla says it provides enough suction to hold the vehicle upside down, even when stationary.

That is the key difference from the wings and diffusers on a normal supercar. Conventional aero only makes downforce when the car is moving, and it grows with speed, so a car has the least grip in the slow corners and under hard braking. A fan system makes downforce at any speed. Tesla’s patent, which we covered last year, describes fans and deployable skirts that create sealed or partially sealed regions under the car, with the fans extracting air to lower the pressure and increase grip and stability.


Tesla pairs that with active wings, a next generation steer by wire system and a Track Mode that lowers the car and changes the suspension, with high downforce and low drag settings for the circuit. To keep weight down, Tesla points to magnesium, titanium and carbon fiber, manual controls and a fixed seat position, which it says lets the car respond to driver inputs almost instantly.

Tesla Roadster: Three configs, one can fly, 0-60 in 0.8 seconds

The cold gas thrusters are the other half. On the Thrust version they sit at the rear and Tesla says they take the car from 0 to 60 mph in under 0.9 seconds, while the Rocket version adds perimeter thrusters for forward, upward and lateral rotational movement. Tesla says the all electric actuators make micro adjustments within a fraction of a second.


Musk has been talking about records for years. In June 2019 he said, “We’re going to do things with the new Roadster that are kind of unfair to other cars.” That September, when a follower asked whether the Roadster would beat the Nürburgring production car record, he replied with one word, “Absolutely,” as we reported at the time. In February 2024 he said Tesla had “radically increased the design goals” for the car and that its sub one second 0 to 60 time would be “the least interesting part.”

There are caveats. Tesla has not published a lap time or a verified cornering figure, so the record talk is still a promise rather than a result. Tesla also says the car is not approved for public road use, and the thruster features are limited to the Rocket trim, which is invite only. Fan cars have also been banned or withdrawn before, and getting a sealed underbody to work on a rough public road is a harder problem than on a smooth track. The first real test will be an official lap at a circuit.

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Tesla Roadster: Three configs, one can fly, 0-60 in 0.8 seconds

Tesla’s Roadster comes in Performance, Thrust and Rocket versions, with a claimed 0-60 under 0.59 seconds.

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Elon Musk addresses the crowd next to the new Tesla Roadster, which Tesla offers in Performance, Thrust and Rocket versions. (Image: Tesla/X)

Tesla finally showed the next generation Roadster on Thursday night, and the demo had more in common with a SpaceX test than a track lap. At an event outside Waco, Texas, near SpaceX’s McGregor site, the car used a mix of fans and cold gas thrusters to drive up a curved ramp until it was upside down, then flew off, flipped and landed on the pavement. “Well, it worked,” Elon Musk said. “Flying cars are real.”

The Roadster also hovered itself over a Cybercab, Cybertruck, Tesla Semi, Model Y and Model 3 while moving, and that Tesla showed it going 0 to 60 mph in one second. Musk said “this will be the actual car that’s on the roads” and that it “literally is just going to puff itself up” to perform the maneuvers whenever an owner wants. He called the result a collaboration between Tesla and SpaceX engineers that is “better than any James Bond car,” with Franz von Holzhausen and Lars Moravy on site.

Tesla published new mind-blowing stats for the car that replace the previous targets. The Performance version is road ready and seats two, with active aerodynamics and a multi-mode suction system, and Tesla lists 0 to 60 mph in under 1.6 seconds. The Thrust version is race ready, also seats two, and adds rear-mounted cold gas thrusters for a 0 to 60 time of under 0.9 seconds. The Rocket version is described as air ready, seats one, and uses perimeter-mounted thrusters for forward and upward acceleration plus lateral rotational movement.

Configuration Seats 0 to 60 mph
Performance 2 under 1.6 s
Thrust 2 under 0.9 s
Rocket 1 under 0.59 s

Tesla’s own description: “So…yes, it can fly.” It lists a 0 to 60 time of under 0.59 seconds for Rocket, a top speed of up to more than 230 mph, and range of more than 300 miles. Tesla has not yet given pricing in the information we have seen, but has reopened $50,000 reservations in the newly updated Tesla Roadster configurator. Production is planned for Giga Texas in 2027 or 2028, and Musk has said it would follow the demo by 12 to 18 months.

Tesla’s Roadster page adds more on how the car works. A multi-mode fan and ground sealing system pulls air from under the car, producing enough suction to hold it upside down even when stationary. Active wings, steer-by-wire with a yoke, and a Track Mode that lowers the car round out the driving setup. The cold gas thrusters use all-electric actuators for micro adjustments to stabilize the car in flight. Tesla says it cut weight with magnesium, titanium and carbon fiber, manual controls and a fixed seat position, and the exterior has hidden headlights, a full-length taillight and Ano White paint inspired by aerospace coatings. Inside are an Ultrawhite interior with gray microsuede, a center touchscreen and two smaller forward displays, and gold tinted glass modeled on spacesuit visors. Availability is tiered: Performance is by reservation, Thrust is a limited release, and Rocket is invite only. Tesla notes the car is not approved for public road use, and that Rocket is not available in all regions.

Tesla Roadster Highlights

  • Aero and suction: a multi-mode fan and ground sealing system pulls air from under the car and can hold it upside down even when stationary. There are also active wings and a Track Mode that lowers the car.
  • Controls and thrusters: steer-by-wire with a yoke. The cold gas thrusters use all-electric actuators for micro adjustments that stabilize the car in flight.
  • Weight: magnesium, titanium and carbon fiber, manual controls and a fixed seat position.
  • Design: hidden headlights, a full-length taillight, Ano White paint inspired by aerospace coatings, and gold tinted glass modeled on spacesuit visors.
  • Interior: an Ultrawhite interior with gray microsuede, a center touchscreen and two smaller forward displays.
  • Availability: Performance is by reservation, Thrust is a limited release, and Rocket is invite only.
  • Road use: Tesla notes the car is not approved for public road use, and that Rocket isn’t available in all regions.

Musk has described the Roadster as “the best of the last of the human-driven cars,” and he has been open that it is a halo product. He said he is “not sure it moves the needle massively from a revenue standpoint,” and has warned that anyone whose top priority is safety should not buy it. Tesla reports third quarter earnings on October 21.

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