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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
SpaceX just launched a secret payload from California
SpaceX launched a classified Space Force mission from Vandenberg, revealing almost nothing about its payload.
SpaceX launched a classified Falcon 9 mission for the U.S. Space Force from Vandenberg Space Force Base on Saturday night, and the government released almost nothing about what was on board. The mission, designated USSF-366, lifted off from Space Launch Complex 4E with a window that opened at 9:52 p.m. ET and ran into the early hours of Sunday, according to SpaceX’s own mission page, which described the payload only as classified. SpaceX confirmed the launch on its X account and pointed viewers to a livestream that began roughly ten minutes before liftoff.
Watch Falcon 9 launch the USSF-366 mission from pad 4E in California https://t.co/FFEzeYOds1
— SpaceX (@SpaceX) August 16, 2026
The lack of detail did not stop analysts from filling in the blanks. Independent tracking of the rocket’s stage drop zones matched the pattern SpaceX has used on previous Starlink Group 15 missions, according to reporting from Outer Space Today, which pointed to Starshield as the likely payload rather than a one off government satellite. Starshield is SpaceX’s national security product, a version of the Starlink satellite bus built to Pentagon specifications for earth observation, communications and hosted payloads. Unlike consumer Starlink, government agencies do not have to disclose what Starshield satellites are actually doing once they reach orbit.
USSF-366 is the latest entry in a steady flow of classified and semi classified work between SpaceX and the Space Force. The company picked up a $178.5 million task order in April to launch missile tracking satellites for the Space Development Agency, as Teslarati reported at the time, and followed that in July with a $1.6 billion award covering 18 more Falcon 9 missions from Vandenberg through the end of 2027, also detailed by Teslarati. Add those contracts up and SpaceX’s Pentagon business for 2026 alone tops $8 billion.
SpaceX scores another massive Pentagon deal to support military satellites
The Falcon 9 that flew Saturday landed back near the launch site, producing the sonic booms that have become routine for residents near Vandenberg. What is less routine is how little the public will likely ever learn about what the rocket carried. SpaceX and the Space Force have not confirmed the Starshield connection, and government satellite programs built on commercial buses rarely get identified beyond a mission number and a general orbit. For a company that live streams almost everything else it does, from Starship test flights to Optimus robot demos, USSF-366 is a reminder that some of SpaceX’s busiest work now happens entirely out of public view.
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On Friday, Tesla launched the Outlet Adapter that enabled Vehicle-to-Load (V2L) energy transfer, meaning owners could essentially utilize their cars as a power source for things like laptops, electric grills, or string lights.
However, even owners of some of the newest builds of the Model Y are finding out that their cars are not compatible with the new $80 accessory, stirring up a new complaint among members of the community.
Tesla launches V2L Outlet Adapter for Premium Model Y in the U.S.
Upon the release of the Outlet Adapter on Friday, I signed into my Tesla account to order the accessory. However, I was met with the dreaded “This product is not compatible with your 2026 Model Y” message at the bottom of the screen.
Some said their accounts also displayed the same message, but they ordered anyway. However, they might be surprised to find that this is no mistake; some of the newest Model Ys do not have the appropriate Power Conversion System (PCS). Mine, which was ordered on this day last year and delivered on August 31, has the old 48A, single-phase PCS.
Vehicles with the new, two-piece PCS are able to utilize V2L features on their cars:
🚨 Looks like you can hit the Parts Catalog and enter your VIN and check to see if your Model Y will be able to use the adapter for V2L.https://t.co/QA9zRk7n2k
h/t to @SawyerMerritt for finding this out.
-I am sad but this isn’t a huge loss. https://t.co/AYpI12QVV9 pic.twitter.com/LRFSrtRywo
— TESLARATI (@Teslarati) August 16, 2026
Obviously, it’s disappointing. Many owners have taken delivery this year and still can not utilize the Outlet Adapter because their cars feature the old PCS:
Took delivery in February of 2026. I have the older one, so not going to work for me pic.twitter.com/RcOVq8gvvT
— Russell (@QuietTesla) August 16, 2026
It looks like if you have one of these older PCS units, you can upgrade, but the parts alone are $1,750, and that’s before Tesla adds labor for installing. It is honestly more logical to get some kind of portable power supply or power station at that point.
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It is great that Tesla has enabled V2L for Model Y vehicles, but it is also unfortunate that vehicles that are less than one year old are not able to take advantage of this awesome new feature.
With that being said, it truly is a first-world problem; can you really complain when Full Self-Driving is available, maintenance is incredibly inexpensive, and the car has been so good through a year of ownership?
Tesla has launched a new Vehicle-to-Load (V2L) Outlet Adapter for Premium Model Y vehicles in the United States, meaning you can now power devices like laptops or light strings with your vehicle’s battery.
It appears the capability will be available for any Model Y Premium trim, including those that were purchased prior to the Adapter being launched. It will also only impact Juniper Model Y vehicles, so the first-gen owners will unfortunately not have access to this capability.
If your Model Y was purchased before Tesla renamed the trim levels to “Premium” and “Standard,” it does not seem to be compatible. My Model Y is technically a Premium build, as it is the Long Range All-Wheel-Drive. However, Tesla says it is not compatible with my vehicle.
🚨 Tesla has launched the Outlet Adapter for Model Y Premium in the U.S., enabling V2L capability for all Premium trims (that’s what it appears to be as it is available for purchase with all Premium trims)
It’s available for $80. 2.4kW max power and rated for 120v, 20A pic.twitter.com/lDxlVIk5s8
— TESLARATI (@Teslarati) August 14, 2026
For $80, you can now utilize your car as a portable charger for small appliances or devices. This is perfect for things like tailgates, concerts, or camping, as you can now plug in devices that you might use. Those string lights for camping? That laptop for the other games that are on at the tailgate?
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They’ll both utilize energy from your Tesla’s battery to be powered. This is the first time Tesla has expanded the capability to vehicles outside of the Model Y Performance and Cybertruck. However, this feature has been highly requested by owners for an extended period of time.
Tesla launched the Outlet Adapter in China last year:
Tesla China rolls out Model Y L V2L adapter, and it’s free for early owners
You will need the Mobile Connector to operate the Outlet Adapter: the Outlet Adapter will plug into the main housing of the Mobile Connector, where the appropriate adapter to charge your vehicle will plug in.
It is rated for 120 volts and 20 amps, and has a max power rating of 2.4kW.
You can buy it here from Tesla for $80.
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SpaceX just launched a secret payload from California
Tesla V2L adapter for Model Y stirs up a new complaint among owners
