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SpaceX sends “radically redesigned” Starship engine to Texas for hot-fire tests

As of September 2017, subscale Raptor engines had been cumulatively fired for more than 1200 seconds in just 12 months of testing. (SpaceX)

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8 years ago

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SpaceX has shipped one of the first of a group of Starship engines known as Raptor, described last month by CEO Elon Musk as “radically redesigned”. A culmination of more than 24 months of prototype testing, the first flight-worthy Raptor could be ignited for the first time as early as February.

According to Musk, three of these redesigned Raptors will power the first full-scale BFR prototype, a Starship (upper stage) test article meant to conduct relatively low-altitude, low-velocity hop tests over the southern tip of Texas. Those tests could also begin next month, although a debut sometime in March or April is increasingly likely.

Effectively designed on a blank slate, Raptor began full-scale component-level tests in 2014 at NASA’s Mississippi-based Stennis Space Center, evolving from main injector development to oxygen preburner hot-fires in 2015. Soon after Raptor’s prototype preburner design was validated at Stennis, SpaceX moved testing to its privately-owned and operated facilities in McGregor, Texas, where Raptor static fire testing has remained since.

Just days before CEO Elon Musk was scheduled to reveal SpaceX’s next-generation rocket (BFR, formerly known as the Interplanetary Transport System or ITS) in September 2016, he announced in a tweet that propulsion engineers and technicians had successful hot-fired an integrated Raptor prototype – albeit subscale – for the first time ever. Just 12 months later, Musk once again took to the stage to announce an update to BFR’s design, while also revealing that prototype Raptor engines had already completed more than 1200 seconds (20 minutes) of cumulative hot-fire tests, an extremely aggressive and encouraging rate of progress for such a new engine.

Although Raptor undoubtedly borrows heavily from much of the same expertise that designed Merlin 1 and operated and improved it for years, that is roughly where the similarities between Raptor and M1D end. M1D, powered by refined kerosene (RP-1) and liquid oxygen, uses a combustion cycle (gas-generator) that is relatively simple and reliable at the cost of engine efficiency, although SpaceX propulsion expertise still managed to give M1D the highest thrust-to-weight ratio of any liquid rocket engine ever flown. Still, measured by ISP (instantaneous specific impulse), M1D’s inefficient kerolox gas-generator cycle ultimately means that the engine simply can’t compete with the performance of engines with more efficient propellants and combustion cycles.

While SpaceX’s Falcon 9 and Heavy rockets – powered by Merlin 1D and Merlin Vacuum – are more than adequate in and around Earth orbit, a far more efficient engine was needed for the company to enable the sort of interplanetary colonization Musk had in mind when he created SpaceX. Raptor was the answer. Ultimately settling on liquid methane and oxygen (methalox) as the propellant and a full-flow staged-combustion (FFSC) cycle, Raptor was designed to be extraordinarily reliable and efficient in order to safely power a spacecraft (BFS/Starship) meant to ferry dozens or hundreds of people to and from Mars.

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An excellent NASASpaceflight article explores the engine’s journey from a blank sheet to integrated static-fire tests and offers a deeper explanation of the technical details.

Raptor enters a new era

For all the extensive and invaluable testing SpaceX has done with a series of prototype Raptor engines, the engines tested were subscale versions with around 30% the thrust of the c. 2016 Raptor and around 40-50% of the updated c. 2017 iteration, producing almost the same amount of thrust as Merlin 1D (914 kN to Raptor’s ~1000 kN). In September 2018, Musk described Raptor as an “approximately…200-ton (~2000 kN) thrust engine” that would eventually operate with a chamber pressure as high as 300 bar (an extraordinary ~4400 psi), requiring at least one of the FFSC engine’s two preburners (used to power separate turbopumps) to operate at a truly terrifying ~810 bar (nearly 12,000 psi).

Conveniently stood beside a Merlin 1D engine also ready for hot-fire acceptance testing, the Raptor engine spotted departing SpaceX’s Hawthorne, CA factory last week was reportedly immense in person, towering over an M1D engine. Raptor also featured a mass of spaghetti-like plumbing (complexity necessary for its advanced combustion cycle), with a significant fraction of the metallic pipes and tubes displaying mirror-like finishes. Most notable was an obvious secondary preburner/turbopump stack and the lack of any exhaust port, whereas M1D relies on a single turbopump and exhausts the gases used to power it. Raptor’s full-flow staged-combustion cycle uses separate oxygen and methane preburners to power separate turbopumps, significantly improving mass flow rate and smoothing out combustion mixing.

 

Unlike all previous hot-fired Raptors, those shipping now to McGregor, Texas are expected to be the first completed engines with a finalized design, arrived at only after a period of extensive testing and iterative improvement. They also appear to be full-scale, meaning that the test bays dedicated to Raptor will likely need to be upgraded (if they haven’t been already) to support a two- or threefold increase in maximum thrust.

SpaceX’s Starship hopper will need three finalized engines, meaning that the Raptor now in McGregor, Texas may not have been the first to arrive. Nevertheless, the shipment of full-scale hardware is always an extremely encouraging milestone for any advanced technology development program, while also foreshadowing the first imminent static-fires of the “radcally redesigned” rocket engine. With hardware now at the test site before January is out, a February test debut – one month behind a January debut teased by Elon Musk last December – is not out of the question.

Check out Teslarati’s newsletters for prompt updates, on-the-ground perspectives, and unique glimpses of SpaceX’s rocket launch and recovery processes!

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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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Investor's Corner

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.

Published

6 hours ago

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October 16, 2026

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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.

Published

18 hours ago

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October 15, 2026

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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.

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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.

Published

20 hours ago

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October 15, 2026

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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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