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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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7 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.

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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.

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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 keroloxย 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.

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 preburnersย to power separate turbopumps, significantly improving mass flow rate and smoothing out combustion mixing.

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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.

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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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Tesla dominates in the UK with Model Y and Model 3 leading the way

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9 hours ago

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December 18, 2025

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Credit: Tesla China

Tesla is dominating in the United Kingdom so far through 2025, and with about two weeks left in the year, the Model Y and Model 3 are leading the way.

The Model Y and Model 3 are the two best-selling electric vehicles in the United Kingdom, which is comprised of England, Scotland, Wales, and Northern Ireland, and it’s not particularly close.

According to data gathered byย EU-EVs, the Model Y is sitting at 18,890 units for the year, while the Model 3 is slightly behind with 16,361 sales for the year so far.

The next best-selling EV is the Audi Q4 e-tron at 10,287 units, lagging significantly behind but ahead of other models like the BMW i4 and the Audi Q6 e-tron.

The Model Y has tasted significant success in the global market, but it has dominated in large markets like Europe and the United States.

For years, it’s been a car that has fit the bill of exactly what consumers need: a perfect combination of luxury, space, and sustainability.

Both vehicles are going to see decreases in sales compared to 2024; the Model Y was the best-selling car last year, but it sold 32,610 units in the UK. Meanwhile, the Model 3 had reached 17,272 units, which will keep it right on par with last year.

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Tesla announces major milestone in the United Kingdom

Tesla sold 50,090 units in the market last year, and it’s about 8,000 units shy of last year’s pace. It also had a stronger market share last year with 13.2 percent of the sales in the market. With two weeks left in 2025, Tesla has a 9.6 percent market share, leading Volkswagen with 8 percent.

The company likely felt some impact from CEO Elon Musk’s involvement with the Trump administration and, more specifically, his role with DOGE. However, it is worth mentioning that some months saw stronger consumer demand than others. For example, sales were up over 20 percent in February. A 14 percent increase followed this in June.

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Tesla Insurance officially expands to new U.S. state

Tesla’s in-house Insurance program first launched back in late 2019, offering a new way to insure the vehicles that was potentially less expensive and could alleviate a lot of the issues people had with claims, as the company could assess and repair the damage itself.

Published

13 hours ago

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December 18, 2025

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Credit: Tesla Insurance

Tesla Insurance has officially expanded to a new U.S. state, its thirteenth since its launch in 2019.

Tesla has confirmed that its in-house Insurance program has officially made its way to Florida, just two months after the company filed to update its Private Passenger Auto program in the state. It had tried to offer its insurance program to drivers in the state back in 2022, but its launch did not happen.

Instead, Tesla refiled the paperwork back in mid-October, which essentially was the move toward initiating the offering this month.

Tesla’s in-house Insurance program first launched back in late 2019, offering a new way to insure the vehicles that was potentially less expensive and could alleviate a lot of the issues people had with claims, as the company could assess and repair the damage itself.

It has expanded to new states since 2019, but Florida presents a particularly interesting challenge for Tesla, as the company’s entry into the state is particularly noteworthy given its unique insurance landscape, characterized by high premiums due to frequent natural disasters, dense traffic, and a no-fault system.

Tesla partners with Lemonade for new insurance program

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Annual average premiums for Florida drivers hover around $4,000 per year, well above the national average. Tesla’s insurance program could disrupt this, especially for EV enthusiasts. The state’s growing EV adoption, fueled by incentives and infrastructure development, aligns perfectly with Tesla’s ecosystem.

Moreover, there are more ways to have cars repaired, and features like comprehensive coverage for battery damage and roadside assistance tailored to EVs address those common painpoints that owners have.

However, there are some challenges that still remain. Florida’s susceptibility to hurricanes raises questions about how Tesla will handle claims during disasters.

Looking ahead, Tesla’s expansion of its insurance program signals the company’s ambition to continue vertically integrating its services, including coverage of its vehicles. Reducing dependency on third-party insurers only makes things simpler for the company’s automotive division, as well as for its customers.

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Tesla Full Self-Driving gets sparkling review from South Korean politician

“Having already ridden in an unmanned robotaxi, the novelty wasnโ€™t as strong for me, but it drives just as well as most people do. It already feels like a completed technology, which gives me a lot to think about.”

Published

15 hours ago

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December 18, 2025

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Credit: Soyoung Lee | X

Tesla Full Self-Driving got its first sparkling review from South Korean politician Lee So-young, a member of the country’s National Assembly, earlier this week.

Lee is a member of the Strategy and Finance Committee in South Korea and is a proponent of sustainable technologies and their applications in both residential and commercial settings. For the first time, Lee was able to utilize Tesla’s Full Self-Driving technology as it launched in the country in late November.

Her thoughts on the suite were complimentary to the suite, stating that “it drives just as well as most people do,” and that “it already feels like a completed technology.”

Her translated post says:

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“Finally, today I got to experience Tesla FSD in Seoul. Thanks to the Model S sponsored by JiDal Papa^^, Iโ€™m truly grateful to Papa. The route was from the National Assembly -> Mangwon Market -> Hongik University -> back to the National Assembly. Having already ridden in an unmanned robotaxi, the novelty wasnโ€™t as strong for me, but it drives just as well as most people do. It already feels like a completed technology, which gives me a lot to think about. Once it actually spreads into widespread use, I feel like our daily lives are going to change a lot. Even I, with my license gathering dust in a drawer, donโ€™t see much reason to learn to drive a manual anymore.”

Tesla Full Self-Driving officially landed in South Korea in late November, with the initial launch being one of Tesla’s most recent, v14.1.4.

It marked the seventh country in which Tesla was able to enable the driver assistance suite, following the United States, Puerto Rico, Canada, China, Mexico, Australia, and New Zealand.

It is important to see politicians and figures in power try new technologies, especially ones that are widely popular in other regions of the world and could potentially revolutionize how people travel globally.

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