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 is lowering the monthly price of its Cybertruck Windshield Protection Plan from $35 to $25. The new rate will apply to the first payment on or after October 1, 2026. Tesla has told subscribers that all other benefits stay the same.
The plan covers unlimited repairs for chips and minor cracks on the front windshield. It also includes one full replacement every 12 months at no extra charge. Additional replacements in the same year carry a $100 deductible. Service is performed with Tesla glass and camera calibration, which matters because Autopilot and Full Self-Driving rely on those lenses behind the windshield.
Looks like Tesla is decreasing the Cybertruck windshield protection plan price from $35 to $25
Awesome https://t.co/MRlTU1XTbf pic.twitter.com/PWkMZt1H7G
— TESLARATI (@Teslarati) August 28, 2026
There is no long-term contract. Coverage applies only to the front glass and does not include collision, vandalism, or weather damage.
The Cybertruck’s large, complex windshield has been more expensive to replace than glass on Tesla’s cars, which is why the pickup started at a higher subscription price. The $10 monthly cut reduces the annual cost from $420 to $300. Tesla has not publicly explained the change. The timing coincides with a year of claims data after the plan was extended to the Cybertruck.
Tesla sells several related protection products as monthly subscriptions through the Tesla app. The Windshield Protection Plan is also offered on other models. Model 3 and Model Y currently cost $16 a month. Those passenger-car rates are unchanged in the latest Cybertruck notice.
The Wheel and Tire Protection Plan covers road-hazard damage such as potholes, nails, and debris. Repairs are unlimited. Each wheel or tire replacement appointment has a $25 deductible. Pricing varies by model and whether the vehicle is a Performance version. Tesla is raising some of those rates on the same October 1 date.
Reported examples include Model 3 Performance moving from $16 to $24 and Model Y Performance from $20 to $24. Cybertruck wheel-and-tire coverage has been listed at $20 a month for the standard configuration.
A separate Luxe Package bundles four years of windshield coverage, wheel-and-tire coverage, and recommended maintenance on certain new Model S, Model X, and Cyberbeast orders, although the Model S and X are now defunct.
Tesla also offers an Extended Service Agreement after the basic vehicle warranty ends. That product covers many Tesla-manufactured parts rather than glass or tires. Together, the plans give owners a menu of targeted, cancel-anytime coverage instead of relying only on auto insurance.
UPDATE: The number has now been updated to 45 units, up from 7!
Here we go! Tesla has just added another 38 Cybercabs to its Robotaxi fleet, bringing the total up to 45, according to the Texas DMV.
Robots on robots on robots! This Thursday’s launch event is gonna be awesome🤖🤖🤖 pic.twitter.com/3HF24rHK4T
— Sawyer Merritt (@SawyerMerritt) August 31, 2026
Tesla is bolstering its Cybercab fleet with the State of Texas’s regulatory bodies ahead of the planned launch of the all-electric ride-hailing vehicle this Thursday.
Seven purpose-built Tesla Cybercabs have been added to Texas’s official automated vehicle registry, appearing in the Texas Motor Carrier Credentialing System (TxMCCS) public lookup just three days before Tesla’s invite-only Cybercab launch event in Austin on September 3.
The records, visible through TxDMV’s Motor Carrier and Automated Motor Vehicle Operator Lookup, list seven 2026 Tesla Cybercabs under Tesla Robotaxi, LLC. Their VINs begin with the 5YJA prefix, distinct from the 7SAYG Model Y robotaxis that already dominate Tesla’s Texas fleet.
Community trackers that scrape the same public database recorded the new entries on August 31, bringing Tesla’s authorized Texas robotaxi total to 276 vehicles: 269 Model Ys and the seven Cybercabs:
🚨 There are now SEVEN Tesla Cybercabs registered with the state of Texas
We are just three days from Cybercab! pic.twitter.com/ndwhuFYsep
— TESLARATI (@Teslarati) August 31, 2026
Texas Senate Bill 2807, which took effect in late May 2026, created a self-certification framework for commercial Level 4 operations. Operators file through TxMCCS, attest to SAE Level 4 capability, maintain insurance, and keep an active vehicle list.
Tesla completed that process months earlier for its existing Model Y Robotaxi service, which has carried paying passengers in Austin, Dallas, Houston and other markets. Adding the Cybercabs to the same authorization means the new two-seat, steering-wheel-free vehicles are now legally recognized for commercial use on Texas roads.
The timing is deliberate as Tesla scheduled the September 3 event at its Austin campus after sending invitations to selected Robotaxi riders and other guests. The company has described the evening as a chance to “experience the future of full autonomy” and plans to livestream it.
Production Cybercabs, which lack pedals and a steering wheel, have been rolling off the Giga Texas line for months; some earlier examples still carried temporary driver controls for data collection. Registering a small fleet of the finished design immediately before the public event signals that Tesla intends to move the purpose-built vehicle from factory and test tracks into the same Robotaxi app already used by Model Y passengers.
The seven units remain a tiny fraction of Tesla’s overall Texas authorization and far smaller than competing fleets. Registration does not automatically equal unsupervised public rides; it is the legal prerequisite.
Still, the sudden appearance of Cybercab VINs in the state’s lookup system, after a year of Model Y-only listings, is the clearest official confirmation yet that Tesla’s dedicated robotaxi hardware is entering the regulatory pipeline at the same moment the company is preparing to show it to invited guests and a global livestream audience.
Whether those seven vehicles appear at the September 3 event or begin carrying passengers shortly afterward, their presence in TxMCCS marks a concrete regulatory step that has been anticipated since the Cybercab concept was first revealed.
Tesla has expanded the operational geofence for its driverless Robotaxi service in Austin, Texas, marking the first such increase in some time. The updated Service Area for Robotaxi in Austin now spans about 288 square miles and is roughly 9 percent larger than the previous boundary.
This incremental growth adds approximately 24 square miles of coverage, bringing the prior zone of roughly 264 square miles into a broader footprint that better serves northern suburbs.
The expansion extends the geofence northward toward Pflugerville along the US 183 corridor, incorporating additional neighborhoods north of the Domain and areas such as Mesa Park. These additions include higher-end residential and commercial districts that previously sat just outside the allowed operating zone.
Riders can now request unsupervised trips that begin or end in these newly included locations, provided the entire route remains inside the digital boundary:
Tesla has just expanded its Robotaxi service area in Austin, Texas for the first time in 10 months.
The new service area is roughly 9% larger than the old one, and is about 288 square miles in total. pic.twitter.com/i4oBM1KfWS
— Sawyer Merritt (@SawyerMerritt) August 31, 2026
Tesla first launched public Robotaxi operations in Austin in mid-2025 with a modest initial zone of about 20 square miles. Subsequent enlargements in 2025 and early 2026 steadily grew the map until it covered much of the metropolitan area.
After the last major update roughly ten months earlier, the company held the boundary steady while it collected additional miles and refined the FSD suite.
The modest nine percent increase still matters for daily utility. Longer trips become possible, more residents gain access, and the fleet can accumulate more diverse real-world data across new road types and traffic patterns. Observers note that the added territory aligns with existing Tesla service infrastructure, which could support more efficient vehicle staging in the North end of Austin.
Although the geofence has grown, Tesla continues to operate a relatively small unsupervised fleet in the city. The company has emphasized safety and software readiness over rapid geographic scaling. This latest map update signals that Tesla remains committed to expanding Robotaxi availability in its home market as it prepares for further software improvements and potential Cybercab deployments.
The 288-square-mile zone now gives Austin riders one of the larger driverless service areas currently available in the United States.
Tesla Cybertruck windshield protection just got cheaper
Tesla Cybercab fleet grows in Austin ahead of launch event
