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.
-
- SpaceX’s current Texas facilities feature a test stand for Raptor, the engine intended to power BFR and BFS to Mars. (SpaceX)
-
- SpaceX’s Raptor proceeds through the complex process of ignition. (SpaceX)
-
- SpaceX’s subscale Raptor engine has completed more than 1200 seconds of testing in less than two years. (SpaceX)
-
- 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.”
Follow us for live updates, peeks behind the scenes, and photos from Teslarati’s East and West Coast photographers.
Teslarati – Instagram – Twitter
Tom Cross – Twitter
Pauline Acalin – Twitter
Eric Ralph – Twitter
Tesla’s Supercharger Diner in Los Angeles dominated the company’s global usage rankings after just one year, proving the concept is more than just a one-off novelty location that will fade away.
The performance could incite the company to build more locations, something that CEO Elon Musk has hinted at for some time.
Tesla’s Supercharger Diner delivered 21.2 GWh of energy in its first year of operation, the company’s head of Charging, Max de Zegher, revealed on X. Of the top 10 most utilized Supercharger locations in Tesla’s global infrastructure, the Diner in Los Angeles was the most used by drivers, and it wasn’t particularly close:
Tesla Diner opened exactly 1 year ago. Inspiring that futuristic places like this exist.
It’s our highest usage Supercharger in the world: 21.2 GWh delivered in a year, 1.6k sessions/day.
Top 10 Superchargers by energy delivered: https://t.co/9YvJ8lw696 pic.twitter.com/koB3AUJHws
— Max (@MdeZegher) July 21, 2026
On its launch day one year ago, nobody was too sure what the Tesla Diner would be about. It seemed like an interesting concept, and considering it had been in the works for years, it was a highly anticipated launch that many were looking forward to.
Based on its success, we could see additional Diners with Superchargers built throughout the United States, and potentially beyond. Musk has said on several occasions that the company would be willing to bring the Diner idea to more markets.
Tesla makes major change at Supercharger Diner amid epic demand
Of the markets that Musk has mentioned, both Palo Alto and Austin have come to be perceived as ideal selections. However, there are no concrete plans as of now to build new Supercharger Diners anywhere; the location on Santa Monica Boulevard will remain the exclusive spot to pick up Tesla-inspired eats, at least for the time being.
Tesla short sellers won big following the company’s massive fall on Wall Street after it reported subpar Earnings on Wednesday.
Tesla short sellers collected about $4.12 billion in single-day profits on Thursday, according to Bloomberg. Shares fell as much as 15 percent during Thursday’s session. It closed as one of the worst days for Tesla on Wall Street in the past three years.
Investors sold off the stock after Tesla said it would aggressively direct its spending toward AI and its Optimus robot project. The company had record revenues, which were driven by one of the strongest quarters in terms of vehicle deliveries in company history.
However, it missed EPS estimates by reporting just $0.33, a far cry from the $0.53 analysts expected.
S3 Partners reported that about 3 percent of Tesla’s outstanding stock is sold short. Managing Director at S3, Ihor Dusaniwsky, provided the short seller’s potential profit, as well as another figure: shorts have likely had paper gains of $8.92 billion this year, as Tesla shares are down 30 percent in 2026.
Tesla (TSLA) Q2 2026 earnings results: miss on EPS, beat on revenue
Tesla has burned short sellers many times in the past, but the company’s latest Earnings Call was a chance for those skeptics to taste some payback. Although the company gave some very transparent information regarding future projects, the rollout of Robotaxi, Optimus, and Semi, many investors took their profits on Thursday.
Notable short sellers like Michael Burry have been transparent about their skepticism around Tesla shares. Burry just revealed three weeks ago that he had opened up a new short on the stock, stating he shorted Tesla shares at $416.22. “Happy it jumped back to this level,” he said in a blog post.
At the time of publication, Tesla shares were down about 3 percent and the stock was trading at $309.92.
Tesla’s long-standing saga regarding its door handles and a manual release has entered its latest chapter, and as a result, a big change is coming.
On Friday, the National Highway Traffic Safety Administration (NHTSA) denied Tesla’s petition that was seeking a defect investigation into roughly 180,000 Model 3 vehicles for an issue involving the emergency mechanical door release.
🚨 The NHTSA denied a petition from Tesla that would have thrown out concerns regarding its door handles.
NHTSA said Tesla’s petition did not present evidence of a safety-related defect warranting an investigation. The agency said a rulemaking process would be a better strategy. pic.twitter.com/j6PzUBM1mT
— TESLARATI (@Teslarati) July 24, 2026
NHTSA said that Tesla’s petition did not present evidence of a safety-related defect in the door handles or their emergency releases. Instead, the agency determined that it would rather solve the issue of the lack of labeling or location of emergency mechanical door releases and the federal safety rules that govern them.
Essentially, the NHTSA wants to create and enforce rules that would require automakers to make emergency door latch releases more clearly labeled in a car. Despite a Tesla having manual door releases on all four passenger doors, many people do not know they exist or how they work.
Tesla addresses door handle complaints with simple engineering fix
In recent times, Tesla has faced some criticism involving its door handles, specifically because some occupants have reported that they are unable to exit their vehicles after losing power. The door handles on a Tesla are electronically operated, but in the event that the 12V battery dies, there is a manual release that can be used.
The NHTSA only identified a single complaint involving the mechanical door releases: a 2022 Model 3 owner said the release was concealed and unlabeled after the vehicle lost power after a front-end collision. It has also already started to create a separate rulemaking process to make emergency door-egress systems more obvious.
It should be noted that all Teslas have mechanical emergency door releases, but they are placed in various locations as the vehicles have aged and been redesigned from year to year. Refer to the safety manual for your vehicle if you have any confusion about where the emergency releases are and how they work.
Tesla’s Supercharger Diner probably just secured more locations
Tesla short sellers win big after shares fall after earnings
