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SpaceX’s Starship Raptor Vacuum engine plans laid out by CEO Elon Musk
Elon Musk says that SpaceX Starship engine upgrades are on track to begin static fire tests of a Raptor Vacuum variant as few as a “couple months” from now.
Designed to enable more efficient performance in thin atmosphere or vacuum, Musk admitted that the first version(s) of Raptor Vacuum (RVac) will likely be a compromise between efficiency and speed of development. Nevertheless, the faster SpaceX can prepare Raptor Vacuum for flight, the easier it will be for Starship to begin serious (sub)orbital flight tests.
As it turns out, SpaceX’s first and only official render of Raptor – published in September 2016 – showed the engine’s vacuum-optimized variant. In the years since, CEO Elon Musk has vacillated between keeping the vacuum engines as a central Starship feature and simply replacing them with regular sea level Raptors to expedite the spacecraft’s debut. The 2016 and 2017 vehicles featured a mixture of vacuum and sea-level engines, whereas Musk revealed a vehicle with sea-level engines only in 2018.



Perhaps less than a month after Musk’s September 2018 presentation, the SpaceX CEO made the decision to radically redesign the vehicle – newly christened Starship and Super Heavy – by moving from a carbon composite aerostructure to stainless steel. At first, the seven SL Raptors remained a part of the design, but Musk took to Twitter in 2019 to indicate that SpaceX had changed gears again and had reprioritized Raptor Vacuum development.
This came as a bit of surprise and it should go without saying that there’s a significant chance that Musk/SpaceX will oscillate in the opposite direction once again before Raptor Vacuum is actually ready for flight. This time, though, Musk has sketched out a development schedule and strategy that suggests SpaceX is much more serious this time.
Most notably, Musk claims that the first Raptor Vacuum prototype could be ready for static fire testing just a “couple months” from now, an immensely ambitious schedule for any large liquid rocket engine development program. Nevertheless, Musk did indicate that the “V1.0” Raptor Vacuum design would be significantly compromised and “suboptimal”, an intentional decision to prioritize the engine’s “speed of development”.
Even then, Musk believes that the first variant – featuring a shortened bell nozzle – could still be up to 12% more efficient than sea level Raptors and thus already 70-80% of the way to the physical limit of methane-oxygen rocket efficiency.

On a positive note, shrinking V1.0 Raptor Vacuum’s nozzle a bit from its nominal length will likely mean that SpaceX can static fire fully-integrated engines at its McGregor, TX test facilities, critical for speedy development. If not, the company has experience with alternatives through Merlin Vacuum, which can only be tested on the ground with its lengthy nozzle detached. This method just makes it dramatically harder to optimize a vacuum nozzle design, as full-scale, flight-like testing is nearly impossible if a given vacuum engine can’t be tested on the ground with said nozzle installed.
Vacuum engines need such large and unwieldy nozzles in order to make them as efficient as possible. In a very simplistic sense, a rocket engine nozzle directs the flow of superheated, ultrafast gases in order to squeeze as much momentum transfer as possible out of available propellant. The lower the pressure of the surrounding atmosphere is, the more those gases will expand immediately after leaving the nozzle – giant vacuum nozzles simply try to harness the additional momentum available from that extra expansion. This is why rocket exhausts appear to spread and thin out as launch vehicles reach higher and higher altitudes.

In this sense, the perfect theoretical vacuum nozzle is quite literally infinitely long. The job of vacuum rocket engineers is to find the perfect balance between that impractical theoretical perfection and the limits of real-world materials and dynamics. In theory, SpaceX’s sea-level Raptor engines have already been designed to operate in vacuum conditions, while the engine’s closed-cycle design and regeneratively (i.e. propellant) cooled nozzle should apply well to a vacuum design.
If SpaceX is lucky, there will be few roadblocks in the way of simply lengthening a SL Raptor-style nozzle and calling it a day, in which case it would be impressive but not all that surprising if SpaceX is actually able to begin RVac testing before the end of 2019. Once a rough V1.0 engine is in place, the process of optimizing efficiency can be done slowly and methodically, all while exploiting an unprecedented wealth of data from flight and orbit-tested Raptor Vacuum engines.
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Tesla Model Y leads South Korea’s EV growth in 2025
Data from the Korea Automobile and Mobility Industry Association showed that the Tesla Model Y emerged as one of the segment’s single biggest growth drivers.
South Korea’s electric vehicle market saw a notable rise in 2025, with registrations rising more than 50% and EV penetration surpassing 10% for the first time.
Data from the Korea Automobile and Mobility Industry Association showed that the Tesla Model Y, which is imported from Gigafactory Shanghai, emerged as one of the segment’s single biggest growth drivers, as noted in a report from IT Home News.
As per the Korea Automobile and Mobility Industry Association’s (KAMA) 2025 Korea Domestic Electric Vehicle Market Settlement report, South Korea registered 220,177 new electric vehicles in 2025, a 50.1% year-over-year increase. EV penetration also reached 13.1% in the country, entering double digits for the first time.
The Tesla Model Y played a central role in the market’s growth. The Model Y alone sold 50,397 units during the year, capturing 26.6% of South Korea’s pure electric passenger vehicle market. Sales of the Giga Shanghai-built Model Y increased 169.2% compared with 2024, driven largely by strong demand for the all-electric crossover’s revamped version.
Manufacturer performance reflected a tightly contested market. Kia led with 60,609 EV sales, followed closely by Tesla at 59,893 units and Hyundai at 55,461 units. Together, the three brands accounted for nearly 80% of the country’s total EV sales, forming what KAMA described as a three-way competitive market.
Imported EVs gained ground in South Korea in 2025, reaching a market share of 42.8%, while the share of domestically produced EVs declined from 75% in 2022 to 57.2% last year. Sales of China-made EVs more than doubled year over year to 74,728 units, supported in no small part by Tesla and its Model Y.
Elon Musk, for his part, has praised South Korean customers and their embrace of the electric vehicler maker. In a reply on X to a user who noted that South Koreans are fond of FSD, Musk stated that, “Koreans are often a step ahead in appreciating new technology.”
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Samsung’s Tesla AI5/AI6 chip factory to start key equipment tests in March: report
Samsung Electronics seems to be ramping its efforts to start operations at its Taylor, Texas semiconductor plant.
Samsung Electronics seems to be ramping its efforts to start operations at its Taylor, Texas semiconductor plant, which will produce Tesla’s next-generation AI5 chip.
Preparing for Tesla’s AI5/AI6 chips
As per a report by Sina Finance, Samsung Electronics is looking to begin trial operations of extreme ultraviolet (EUV) lithography equipment at its Taylor facility in March. These efforts are reportedly intended to support the full production of Tesla’s AI5 chips starting in the latter half of 2026.
The Taylor factory, Samsung’s first wafer fabrication plant in the United States, covers roughly 4.85 million square meters and is nearing completion. Media reports, citing contractors, have estimated that about 7,000 workers now work on the factory, about 1,000 of whom are reportedly working from the facility’s office building.
Samsung is reportedly preparing to apply for a temporary occupancy permit, which would allow production to begin before the plant is fully completed.
Tesla’s aggressive AI chip roadmap
Elon Musk recently stated that Tesla’s next-generation AI5 chip is nearly complete, while early development on its successor, AI6, is already underway. Musk shared the update in a post on X, which also happened to be a recruiting message for engineers.
As per Musk, Tesla is looking to iterate its in-house AI chips on an accelerated timeline, with future generations, including AI7, AI8, and AI9, targeting a roughly nine-month design cycle. He also stated that the rapid cadence could allow Tesla’s chips to become the highest-volume AI processors in the world.
Previous reports have indicated that Samsung Electronics would be manufacturing Tesla’s AI5 chip, alongside its rival, Taiwan Semiconductor Manufacturing Company (TSMC). The two suppliers are expected to produce different versions of Tesla’s AI5 chip, with TSMC using a 3nm process and Samsung targeting 2nm production.
Elon Musk
Elon Musk’s Boring Company studying potential Giga Nevada tunnel: report
The early-stage feasibility work was funded by a state-affiliated economic group as officials searched for alternatives to worsening traffic and accidents along Interstate 80.
Elon Musk’s tunneling startup, The Boring Company, has been studying a potential tunnel system connecting Reno to Tesla Gigafactory Nevada, as per documents obtained by Fortune. The early-stage feasibility work was funded by a state-affiliated economic group as officials searched for alternatives to worsening traffic and accidents along Interstate 80.
Potential Giga Nevada tunnel
Documents reviewed by Fortune showed that The Boring Company received $50,000 in October to produce conceptual designs and a feasibility report for a tunnel beneath a nine-mile stretch of highway leading to Gigafactory Nevada. The payment came from the Economic Development Authority of Western Nevada (EDAWN), a nonprofit that works with the state to attract and expand businesses.
The proposed tunnel was one of several transportation alternatives being explored to address rising congestion and accidents along Interstate 80, which serves the Tahoe-Reno Industrial Center. The massive industrial park houses major employers, including Tesla and Panasonic, both of which had been in contact with the Nevada Governor’s Office regarding potential transportation solutions.
Emails obtained through public records requests showed that Tesla and Panasonic have also supported a separate commuter rail study that would use existing freight rail alongside the Interstate. It remains unclear if The Boring Company’s feasibility report had been completed, and key details for the potential project, including tunnel length, cost, and if autonomous Teslas would be used, were not disclosed.

Relieving I-80 congestion
Traffic and accidents along I-80 have increased sharply as data centers and new businesses moved into the 107,000-acre industrial center. State transportation data showed that the number of vehicles traveling certain stretches of the highway during peak hours doubled between January and July 2025 alone. Roughly 22,000 employees commute daily to the industrial park, with nearly 8,000 working for Tesla and more than 4,000 for Panasonic at the Giga Nevada complex.
Bill Thomas, who runs the Regional Transportation Commission of Washoe County, shared his thoughts about safety concerns in the area. “At this point in time, there’s about (one accident) every other day,” he said. He also noted that he is supportive of any projects that could alleviate traffic and accidents on the Interstate.
“We’re not paying for it. I’m not involved in it. But I understand there are conversations exploring whether that could be done. If there’s a private solution that helps the problem and improves safety, as far as I’m concerned, more power to them,” Thomas stated.