News
SpaceX to use superalloys in Mars rocket Raptor engines, says Elon Musk
A few days after he touched upon methods of creating BFR propellant on Mars, SpaceX CEO Elon Musk mentioned in a tweet that the launch company was using cutting-edge combinations of metals (known as superalloys) to ensure the efficiency and reliability of its Raptor rocket engine, a critical requirement for BFR to enable sustainable colonization of Mars.
In response to a tweeted question about types of metal alloys currently in use at SpaceX, Musk briefly delved into the complexities of building BFR’s propulsion system, particularly with respect to alloys capable of surviving the intense conditions inside a rocket engine:
“[SpaceX is using] SX 300 & soon SX 500. Kind of a modern version of Inconel superalloys. High strength at temperature, extreme oxidation resistance. Needed for ~800 atmosphere, hot, oxygen-rich turbopump on Raptor rocket engine.” – Elon Musk
There’s a lot to break down for the layperson in Musk’s tweet. First and foremost, commenters (your author included) immediately jumped to the conclusion that “SX 300/500” referred to some sort custom SpaceX material, given that SX is a frequent shorthand for SpaceX used in the enthusiast community. In reality, it was quickly discovered that the requirements Musk described for the material – namely “high strength at temperature [&] extreme oxidation resistance” – were nearly the exact same qualities of single-crystal superalloys, extremely advanced metal formulations also notated as SC or SX. It’s quite the apt coincidence that SpaceX will apparently rely on SX alloys for critical components of BFR propulsion.
A 2017 test-firing of the mature development Raptor, roughly 50% less powerful than the full-scale system. (SpaceX)
Single-crystal superalloys employ small amounts of exotic elements in order to better ensure truly unusual crystal formation in metal structures. In the case of SX alloys, the optimal result is a monolithic metal structure that effectively has no visible grain (think wood grain but in metal) – the resulting metal would be a huge monolithic crystal, in other words, uniform down to a near-atomic level. These SX superalloys are already used regularly for industrial applications requiring the ability to reliably operate in extremely corrosive high-pressure, high-temperature environments for long periods of time, most frequently seen in gas turbines for energy generation and airplane propulsion.
Per Musk, SpaceX intends to take those alloys a step further, developing its own SX-300 and SX-500 iterations for the purpose of building a reliable, robust turbopump for the Raptor propulsion system. In pursuit of the greatest possible efficiency, Raptor’s turbopump will run oxygen-rich, meaning that the inherently imperfect combustion process will lean towards excess oxygen in the exhaust, rather than excess methane. In simple terms, this choice is partially motivated by the fact that oxygen molecules are slightly lighter than methane molecules (15.999u vs. 16.04u). More importantly, the higher the pressure in the turbopump, the higher the pressure in Raptor’s combustion chamber, which directly correlates with more efficient combustion and thus a more efficient rocket engine overall. All improvements to its subcomponents will inherently end up benefiting SpaceX’s BFR booster and spaceship, the latter of which is already nearing initial prototype construction.
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- SpaceX’s current Texas facilities feature a test stand for Raptor, the engine intended to power BFR and BFS to Mars. (SpaceX)
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- SpaceX’s Raptor proceeds through the complex process of ignition. (SpaceX)
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- SpaceX’s subscale Raptor engine has completed more than 1200 seconds of testing in less than two years. (SpaceX)
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- SpaceX’s three-bay Raptor test stand as of April 17. The middle bay is currently home to the subscale Raptor test program. (Aero Photo)
While SpaceX cut its original Raptor specifications by roughly 50% compared to its 2016 goals, it appears that the company’s ambitions for the downsized Raptor are smaller in name only. In a May 2018 presentation, Chief of Propulsion Tom Mueller foreshadowed those future ambitions while humbly acknowledging that the Merlin 1D powering Falcon 9 and Heavy is already a masterpiece of engineering: “Merlin holds the thrust to weight record for now… but Raptor’s coming.”
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News
Tesla Model X shocks everyone by crushing every other used car in America
The Model X is one of Tesla’s flagship models, the other being the Model S. Earlier this year, Tesla confirmed it would discontinue production of both the Model S and Model X to make way for Optimus robot production at the Fremont Factory in Northern California.
The Tesla Model X was the fastest-selling used vehicle in the United States in the first quarter of the year, crushing every other used car in America.
iSeeCars data for the first quarter shows that the Model X was the fastest-selling used car, lasting just 25.6 days on the market on average, two days better than that of the second-place Lexus RX 350h. The Cybertruck, Model Y, and Model S, in seventh, ninth, and thirteenth place, respectively, also made the list.
The Model X is one of Tesla’s flagship models, the other being the Model S. Earlier this year, Tesla confirmed it would discontinue production of both the Model S and Model X to make way for Optimus robot production at the Fremont Factory in Northern California.
Tesla brings closure to flagship ‘sentimental’ models, Musk confirms
Bringing closure to these two vehicles signaled the end of the road for the cars that have effectively built Tesla’s reputation for luxury and high-end passenger vehicles.
Relying on the sales of its mass market Model Y and Model 3, as well as leaning on the success of future products like the Cybercab, is the angle Tesla has chosen to take.
Teslas are also performing extremely well as a whole on the resale market. iSeeCars data shows that, “while the average price of a 1- to 5-year-old non-Tesla EV fell 10.3% in Q1 2026 year-over-year, the average price of a used Tesla was essentially flat at 0.1% lower across the same period. Traditional gas car prices dropped 2.8% during this same period.”
Additionally, market share for gas cars has dropped nearly 3 percent since the same quarter last year. Tesla has remained level, while the non-Tesla EV market share has increased 30 percent, mostly due to more models available.
Nevertheless, those non-Tesla EVs have seen their value drop by over 10 percent, while Tesla’s values have remained level.
Executive Analyst Karl Brauer said:
“Used electric vehicles without a Tesla badge have lost more than 10% of their value in the past year. This compares to stable values for Teslas and hybrids, and a modest 2.8% drop for traditional gasoline vehicles.”
Teslas, as well as non-luxury hybrids, are displaying the strongest resistance in the face of faltering demand, the publication says. But the more impressive performance is that of the Model X alone.
Tesla’s decision to stop production of the Model X may have played some part in the vehicle’s pristine performance in Q1. With the car already placed at a premium price point, used models are already more appealing to consumers. Perhaps second-hand versions were more than enough for those who wanted a Model X, and only a Model X.
Cybertruck
Tesla Cybertruck’s head-scratching trim sold terribly, recall documents reveal
The head-scratching offering was only available for a few months, and evidently, it did not sell very well, which we all suspected. New recall documents on the vehicle from the National Highway Traffic Safety Administration (NHTSA) now reveal just how poorly it sold.
After Tesla decided to build a Rear-Wheel-Drive Cybertruck trim back in 2025, which was void of many features and only featured a small discount.
The head-scratching offering was only available for a few months, and evidently, it did not sell very well, which we all suspected. New recall documents on the vehicle from the National Highway Traffic Safety Administration (NHTSA) now reveal just how poorly it sold.
The recall deals with a potentially separating wheel stud and potentially impacts 173 Cybertruck units with the 18-inch steel wheels. The Cybertruck RWD was the only trim level to feature these, and the 173 potentially impacted units represent a portion of the population of pickups. Therefore, it’s not the entire number of RWD Cybertruck sold, but it could show how little interest it gathered.
The NHTSA document states:
“On affected vehicles, higher severity road perturbations and cornering may strain the stud hole in the wheel rotor, causing cracks to form. If cracking propagates with continued use and strain, the wheel stud could eventually separate from the wheel hub.”
Only 5 percent are expected to be impacted, meaning less than 10 units will have the issue if the NHTSA and Tesla estimates are correct. Nevertheless, the true story here is how terribly the RWD Cybertruck sold.
Tesla ended production and stopped offering the RWD Cybertruck to customers last September. For just $10,000 less than the All-Wheel-Drive trim, Tesla offered the RWD Cybertruck with just one motor, textile seats instead of leather, only 7 speakers instead of 15, no Rear Touchscreen, no Powered Tonneau Cover for the truck bed, and no 120v/240v outlets.
For just $10,000 more, at $79,990, owners could have received all of those premium features, as well as a more capable All-Wheel-Drive powertrain that featured Adaptive Air Suspension. The discount simply was not worth the sacrifices.
Orders were few and far between, and sources told us that when it was offered, sales were extremely tempered because customers could not see the value in this trim level.
Even Tesla’s most loyal supporters thought the offering was kind of a joke, and the $10,000 extra was simply worth it.
News
Tesla Semi sends clear message to Diesel rivals with latest move
The truck is being built at a dedicated facility in Sparks, Nevada, just next to its Gigafactory Nevada facility.
Tesla has officially launched Semi production at what will be a mind-boggling rate of approximately 50,000 units per year.
The truck is being built at a dedicated facility in Sparks, Nevada, just next to its Gigafactory Nevada facility.
The company finally announced on April 29 that the first Tesla Semi truck has rolled off its new high-volume production line at the factory. This marks the transition from limited pilot builds to scaled manufacturing for the Class 8 all-electric heavy-duty truck, nearly nine years after its dramatic 2017 unveiling.
🚨 Tesla Semi mass production is underway in Nevada!
HUGE! https://t.co/ohgQIiI2bK pic.twitter.com/23GvWr8D27
— TESLARATI (@Teslarati) April 29, 2026
Tesla initially promised high-volume deliveries by 2019–2020, but battery supply constraints and prioritization for passenger vehicles delayed progress. The new 1.7-million-square-foot factory, purpose-built next to Gigafactory Nevada’s 4680 cell production lines, resolves those bottlenecks through deep vertical integration.
The Semi uses Tesla’s structural battery packs with cylindrical 4680 cells manufactured on-site. This integration enables efficient supply, reduced logistics costs, and the potential for high output. The factory is designed for an eventual annual capacity of approximately 50,000 trucks, positioning Tesla to address growing demand in long-haul freight electrification.
Tesla is using a redesigned Cybertruck battery cell to mitigate Semi challenges
Operating economics favor the Semi through dramatically lower fuel and maintenance costs compared to traditional diesel rigs, and companies involved in a pilot program for the Semi with Tesla have shown that.
Electricity is far cheaper than diesel on a per-mile basis, while the electric powertrain features fewer moving parts, reducing service intervals and lifetime expenses. Early deployments with customers like PepsiCo and others have validated these advantages in real-world service.
The Nevada factory’s ramp-up is targeted for full volume output before the end of June 2026, aligning with broader Tesla production goals for 2026. This includes parallel efforts on other new vehicles while expanding the Megacharger infrastructure to support widespread adoption.
By localizing battery and truck production, Tesla gains advantages in cost, quality control, and scalability that many competitors sourcing cells externally lack. The start of high-volume Semi production represents a pivotal step in Tesla’s strategy to electrify heavy transportation, potentially accelerating the shift toward zero-emission freight across North America and beyond.
As output increases, the Semi could reshape long-haul logistics with its combination of performance, efficiency, and sustainability.
Tesla Model X shocks everyone by crushing every other used car in America
Tesla Cybertruck’s head-scratching trim sold terribly, recall documents reveal
