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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.
- 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.”
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News
Tesla Model S and X customization options begin to thin as their closure nears
Tesla’s Online Design Studio for both vehicles now shows the first color option to be listed as “Sold Out,” as Lunar Silver is officially no longer available for the Model S or Model X. This color is exclusive to these cars and not available on the Model S or Model X.
Tesla Model S and Model X customization options are beginning to thin for the first time as the closure of the two “sentimental” vehicles nears.
We are officially seeing the first options disappear as Tesla begins to work toward ending production of the two cars and the options that are available to those vehicles specifically.
Tesla’s Online Design Studio for both vehicles now shows the first color option to be listed as “Sold Out,” as Lunar Silver is officially no longer available for the Model S or Model X. This color is exclusive to these cars and not available on the Model S or Model X.
🚨 Tesla Model S and Model X availability is thinning, as Tesla has officially shown that the Lunar Silver color option on both vehicles is officially sold out
To be fair, Frost Blue is still available so no need to freak out pic.twitter.com/YnwsDbsFOv
— TESLARATI (@Teslarati) February 25, 2026
Tesla is making way for the Optimus humanoid robot project at the Fremont Factory, where the Model S and Model X are produced. The two cars are low-volume models and do not contribute more than a few percent to Tesla’s yearly delivery figures.
With CEO Elon Musk confirming that the Model S and Model X would officially be phased out at the end of the quarter, some of the options are being thinned out.
This is an expected move considering Tesla’s plans for the two vehicles, as it will make for an easier process of transitioning that portion of the Fremont plant to cater to Optimus manufacturing. Additionally, this is likely one of the least popular colors, and Tesla is choosing to only keep around what it is seeing routine demand for.
During the Q4 Earnings Call in January, Musk confirmed the end of the Model S and Model X:
“It is time to bring the Model S and Model X programs to an end with an honorable discharge. It is time to bring the S/X programs to an end. It’s part of our overall shift to an autonomous future.”
Fremont will now build one million Optimus units per year as production is ramped.
News
Tesla Cybertruck Dual Motor AWD estimated delivery slips to early fall 2026
Tesla has also added a note on the Cybertruck design page stating that the vehicle’s price will increase after February 28.
Tesla’s estimated delivery window for new Cybertruck Dual Motor All-Wheel Drive (AWD) orders in the United States has shifted to September–October 2026. This suggests that the vehicle’s sub-$60,000 variant is now effectively sold out until then.
The updated timeline was highlighted in a post on X by Tesla watcher Sawyer Merritt, who noted that the estimated delivery window had moved from June 2026 to September-October 2026, “presumably due to strong demand.”
The Dual Motor AWD currently starts at $59,990 before incentives. Tesla has also added a note on the Cybertruck design page stating that the vehicle’s price will increase after February 28.
If demand remains steady, the combination of a later delivery window and a pending price increase suggests Tesla is seeing sustained interest in the newly-introduced Cybertruck configuration. This was highlighted by Elon Musk on X, when he noted that the Cybertruck Dual Motor AWD’s introductory price will only be available for a limited time.
When the Cybertruck was first unveiled in November 2019, Tesla listed the Dual Motor AWD variant at $49,990. Adjusted for inflation, that figure equates to roughly $63,000 in 2026 dollars, based on cumulative U.S. inflation since 2019.
That context makes a potential post-February price in the $64,000 to $65,000 range less surprising, especially as material, labor, and manufacturing costs have shifted significantly over the past several years.
While Tesla has not announced a specific new MSRP, the updated delivery timeline and pricing note together suggest that the Cybertruck Dual Motor AWD could very well be the variant that takes the all-electric full-sized pickup truck to more widespread adoption.
Elon Musk
SpaceX targets 150Mbps per user for upgraded Starlink Direct-to-Cell
If achieved, the 150Mbps goal would represent a significant jump from the current performance of Starlink Direct-to-Cell.
SpaceX is targeting peak download speeds of 150Mbps per user for its next-generation Direct-to-Cell Starlink service. The update was shared by SpaceX Spectrum & Regulatory Affairs Lead Udrivolf Pica during the International Telecommunication Union’s Space Connect conference.
“We are aiming at peak speeds of 150Mbps per user,” Pica said during the conference. “So something incredible if you think about the link budgets from space to the mobile phone.”
If achieved, the 150Mbps goal would represent a significant jump from the current performance of Starlink Direct-to-Cell.
Today, SpaceX’s cellular Starlink service, offered in partnership with T-Mobile under the T-Satellite brand, provides speeds of roughly 4Mbps per user. The service is designed primarily for texts, low-resolution video calls, and select apps in locations that traditionally have no cellular service.
By comparison, Ookla data shows median 5G download speeds of approximately 309Mbps for T-Mobile and 172Mbps for AT&T in the United States, as noted in a PCMag report. While 150Mbps would still trail the fastest terrestrial 5G networks, it would place satellite-to-phone broadband much closer to conventional carrier performance, even in remote areas.
Pica indicated that the upgraded system would support “video, voice, and data services, clearly,” moving beyond emergency connectivity and basic messaging use cases.
To reach that target, SpaceX plans to upgrade its existing Starlink Direct-to-Cell satellites and add significant new capacity. The company recently acquired access to radio spectrum from EchoStar, which Pica described as key to expanding throughput.
“More spectrum means a bigger pipeline, and this means that we can expand what we can do with partners. We can expand the quality of service. And again, we can do cellular broadband basically, cellular broadband use cases, like AI or daily connectivity needs,” he stated.
SpaceX has also requested regulatory approval to deploy 15,000 additional Direct-to-Cell satellites, beyond the roughly 650 currently supporting the system. The upgraded architecture is expected to begin rolling out in late 2027.



