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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 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.

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.

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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 Giga Shanghai celebrates 5 million electric drive unit milestone

The milestone was celebrated by the company in a post on its official Weibo account.

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1 hour ago

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January 8, 2026

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Tesla China has reached another manufacturing milestone at Gigafactory Shanghai, rolling out the facility’s 5 millionth locally produced drive unit. 

The milestone was celebrated by the company in a post on its official Weibo account. In its post, the Giga Shanghai team could be seen posing with the 5 millionth drive unit.

Giga Shanghai’s major benchmark

The milestone drive unit was produced at Gigafactory Shanghai, which produces the Model Y and the Model 3. In a release, Tesla China noted that its three-in-one integrated electric drive system combines the motor, gearbox, and inverter into a single compact assembly. This forms a powerful “heart” for the company’s electric cars.

Tesla China also noted that its drive units’ integrated design improves energy conversion efficiency while reducing overall weight and complexity, benefits that translate into stronger performance, improved handling, and longer service life for its vehicles.

Credit: Tesla China

The new milestone builds on earlier achievements at the same site. In July 2024, Tesla announced that its 10 millionth electric drive system globally had rolled off the line at the Shanghai plant, making it the first self-produced Tesla component to reach that volume. 

More recently, the factory also produced its 4 millionth China-made vehicle, a Model Y L. The factory has also continued hitting global production milestones, rolling out Tesla’s 9 millionth EV worldwide late last year, with the landmark vehicle being a Tesla Model Y.

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Tesla China’s role

Construction of Giga Shanghai began in January 2019, with production starting by the end of that year. This made it the first wholly foreign-owned automotive manufacturing project in China. The facility began delivering Model 3 vehicles locally in early 2020 and added Model Y production in 2021. The plant is now capable of producing about 1 million vehicles annually.

Credit: Tesla China

Throughout 2025, Giga Shanghai delivered 851,732 vehicles, representing a 7.08% year-on-year decline, according to data compiled by CNEVPost. Even so, recent months showed renewed momentum. 

In December alone, Tesla China recorded wholesale sales of 97,171 vehicles, including domestic deliveries and exports, making it the company’s second-best monthly total on record, per data from the China Passenger Car Association. Retail sales during December reached roughly 94,000 units, up about 13% year over year.

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Investor's Corner

Tesla price target boost from its biggest bear is 95% below its current level

Published

6 hours ago

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January 7, 2026

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Credit: Tesla China

Tesla stock (NASDAQ: TSLA) just got a price target boost from its biggest bear, Gordon Johnson of GLJ Research, who raised his expected trading level to one that is 95 percent lower than its current trading level.

Johnson pushed his Tesla price target from $19.05 to $25.28 on Wednesday, while maintaining the ‘Sell’ rating that has been present on the stock for a long time. GLJ has largely been recognized as the biggest skeptic of Elon Musk’s company, being particularly critical of the automotive side of things.

Tesla has routinely been called out by Johnson for negative delivery growth, what he calls “weakening demand,” and price cuts that have occurred in past years, all pointing to them as desperate measures to sell its cars.

Johnson has also said that Tesla is extremely overvalued and is too reliant on regulatory credits for profitability. Other analysts on the bullish side recognize Tesla as a company that is bigger than just its automotive side.

Many believe it is a leader in autonomous driving, like Dan Ives of Wedbush, who believes Tesla will have a widely successful 2026, especially if it can come through on its targets and schedules for Robotaxi and Cybercab.

Justifying the price target this week, Johnson said that the revised valuation is based on “reality rather than narrative.” Tesla has been noted by other analysts and financial experts as a stock that trades on narrative, something Johnson obviously disagrees with.

Dan Nathan, a notorious skeptic of the stock, turned bullish late last year, recognizing the company’s shares trade on “technicals and sentiment.” He said, “From a trading perspective, it looks very interesting.”

Tesla bear turns bullish for two reasons as stock continues boost

Johnson has remained very consistent with this sentiment regarding Tesla and his beliefs regarding its true valuation, and has never shied away from putting his true thoughts out there.

Tesla shares closed at $431.40 today, about 95 percent above where Johnson’s new price target lies.

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I subscribed to Tesla Full Self-Driving after four free months: here’s why

It has been incredibly valuable to me, and that is what my main factor was in considering whether to subscribe or not. It has made driving much less stressful and much more enjoyable.

Published

16 hours ago

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January 7, 2026

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Credit: Teslarati

I have been lucky enough to experience Tesla Full Self-Driving for the entire duration of my ownership experience for free — for four months, I have not had to pay for what I feel is the best semi-autonomous driving suite on the market.

Today, my free trial finally ran out, and I had two choices: I could go without it for a period until I felt like I absolutely needed it, or I could subscribe to it, pay $99 per month, and continue to experience the future of passenger transportation.

I chose the latter, here’s why.

Tesla Full Self-Driving Takes the Stress Out of Driving

There are a handful of driving situations that I don’t really enjoy, and I think we all have certain situations that we would just rather not encounter. This is not to say that I won’t ever experience them as someone who has driven a car for 15 years (it feels weird saying that).

I don’t love to drive in cities; I really don’t like driving on I-695 on my way to Baltimore, and I truly hate parallel parking. All three things I can do and have done, all three within the past few weeks, too.

However, if I can avoid them, I will, and Tesla Full Self-Driving does that for me.

Tesla Full Self-Driving Eliminates the Monotony

I drive to my alma mater, Penn State University, frequently in the Winter as I am a season ticket holder to Wrestling and have been for 16 years now.

The drive to State College is over two hours and over 100 miles in total, and the vast majority of it is boring as I travel on Rt 322, which is straight, and there is a lot of nature to look at on the way.

I am willing to let the car drive me on that ride, especially considering it is usually very low traffic, and the vast majority of it is spent on the highway.

The drive, along with several others, is simply a boring ride, where I’d much rather be looking out the windshield and windows at the mountains. I still pay attention, but having the car perform the turns and speed control makes the drive more enjoyable.

Tesla Full Self-Driving Makes Navigating Easier

Other than the local routes that I routinely travel and know like the back of my hand, I’ve really enjoyed Full Self-Driving’s ability to get me to places — specifically new ones — without me having to constantly check back at the Navigation.

Admittedly, I’ve had some qualms with the Nav, especially with some routing and the lack of ability to choose a specific route after starting a drive. For example, it takes a very interesting route to my local Supercharger, one that nobody local to my area would consider.

But there are many times I will go to a new palce and I’m not exactly sure where to go or how to get there. The Navigation, of course, helps with that. However, it is really a luxury to have my car do it for me.

To Conclude

There was no doubt in my mind that when my Full Self-Driving trial was up, I’d be subscribing. It was really a no-brainer. I am more than aware that Full Self-Driving is far from perfect, but it is, without any doubt, the best thing about my Tesla, to me.

It has been incredibly valuable to me, and that is what my main factor was in considering whether to subscribe or not. It has made driving much less stressful and much more enjoyable.

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