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SpaceX CEO Elon Musk hints that Starship’s ‘sweating’ metal heat shield is no more
In the latest entry of SpaceX’s ever-changing Starship design process, CEO Elon Musk has indicated that the nominally reusable orbital spacecraft has moved away from a liquid-cooled steel heat shield to something slightly more traditional.
This information came as a SpaceX engineer announced during Cargo Dragon’s CRS-18 webcast that the twice-flown spacecraft would mark the first orbital test of a ceramic heat shield tile meant for use on Starship’s windward side. This major design change comes as a significant surprise and seems likely to either delay Starship’s orbital debut or hinder its ultimate reusability, although Musk just as recently claimed that the spacecraft could reach orbit for the first time less than six months from now.
Testing a possible Starship windward side ceramic tile. Maximizing emissivity is best for conductive/particle heating. Nice thing about steel is that tiles can be very thin, unlike carbon fiber or aluminum airframe.— ln(e) (@elonmusk) July 25, 2019
Thin tiles on windward side of ship & nothing on leeward or anywhere on booster looks like lightest option— ln(e) (@elonmusk) July 25, 2019
Back in late-2018 and early-2019, Musk took to Twitter to announce that SpaceX was pursuing an exotic metallic heat shield that would be cooled in large part by flowing liquid methane through tiny holes on its exterior, effectively ‘sweating’ away energy and preventing steel tiles from melting.
Despite incontrovertible evidence that SpaceX performed some amount of significant testing on the hexagonally-tiled steel heat shield concept, Musk’s July 24th tweets indicate that the liquid-cooled heat shield is unlikely to ever be used on Starship. For unknown reasons, SpaceX is instead pursuing some sort of thin ceramic heat shielding to protect the entirety of Starship’s windward side (i.e. the side facing the atmosphere during reentry). A handful of the first flight-qualified ceramic tiles – shaped for Dragon instead of Starship – will be tested on Cargo Dragon during the spacecraft’s orbital mission and eventual reentry.
Of note, this is not the only major design change Starship has undergone in just the last few months. Speaking on May 30th, Elon Musk stated that the design of Starship’s landing legs/fins and actuating wings and flaps has changed significantly since SpaceX revealed the new tripod fins + canard wings configuration in September 2018. According to Musk, that change will (or at least should) not significantly impact Starship’s schedule.
In fact, per his July 2019 claims that the first full-fidelity Starship prototype(s) could begin test flights in September/October and reach orbit as early as December/January, the Starship/Super Heavy schedule has actually radically sped up in the first half of 2019. In December 2018, Musk stated that he believed Starship had a 60% chance of reaching orbit in 2020, let alone late-2019.
For Starship, the massive spacecraft’s heat shield is arguably its single most important component. A failure to ensure that the heat shield is unprecedentedly reusable and reliable – even in the face of ultra-high-velocity interplanetary reentries – will severely limit Starship’s ability to achieve its ultimate goals of enabling affordable access to space and building a sustainable city on Mars. Musk’s comment that ceramic tiles are just “a possible” Starship heat shield element further indicates that SpaceX has yet to firmly settle on a heat shield design, let alone qualify said shield for orbital flight or kick off the mass-production necessary to completely cover multiple Starship halves.
Admittedly, there is still some good news in this unfortunate development. Most notably, the fact that Starship will still be made of steel means that the non-metallic heat shield tiles can be extremely thin and light, as they can be more or less directly attached to Starship’s steel hull. Additionally, steel Super Heavy boosters may be able to get away with zero heat shielding thanks to the relatively high melting point and heat resistance of certain varieties of stainless steel.
So long as both of those characteristics remain true, it’s likely that it will still make sense for Starship/Super Heavy to be built entirely out of steel instead of something like aluminum or carbon composite. With any luck, Elon Musk will provide a detailed update on the status of SpaceX’s next-generation launch vehicle soon after Starhopper survives its first untethered flight test.
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A Tesla Semi caught fire in Hayward, California, which caused both directions of traffic to shut down for hours before being completely reopened early on Wednesday, the California Highway Patrol said.
The fire occurred just after 5:30 local time in Hayward on Tuesday, as the Semi caught fire in the southbound lanes of I-880 before CHP officials made the decision to shut down both lanes of traffic due to potential risks from hazardous chemical smoke.
There were no injuries reported.
🚨 A Tesla Semi reportedly caught fire, with California Highway Patrol confirming. The Semi was on I-880 SB
An estimated 5,000 to 7,000 semi-truck and large commercial vehicle fires occur on U.S. roadways every year
— TESLARATI (@Teslarati) October 28, 2026
The cause of the fire is currently unknown, as neither Tesla nor the CHP have not determined a cause.
However, some images taken before the Semi was completely destroyed by the fire seem to indicate this might have been an older unit, as it appears to be one of the designs that Tesla shipped as part of its pilot program, before revising it and starting mass production just a month ago.
@Tslachan From on of the videos looks like it’s an old Semi (not the refresh version that recently started production) https://t.co/KzwmR2kXow
— Area Under The Curve 🎗️ (@AreaUnderCurve) October 28, 2026
At the time of publication, CHP had not returned our request for a comment for additional details, including the Semi involved and any potential collaboration on an investigation between the CHP and Tesla. We will update this story when we hear back from them.
The southbound lanes were reopened at 3:30 a.m. on Wednesday, with the northbound lanes opening last night a few hours after the fire began. The CHP did state that the lithium batteries were “incredibly difficult to extinguish,” according to NBC Bay Area.
The truck’s driver said that the Semi caught fire, but he did not have an explanation.
An estimated 5,000 to 7,000 semi-truck and large commercial vehicle fires occur on U.S. roadways every year.
Tesla’s launch of the “Emergency Drive Away” function a few months back offered owners a safe option to evacuate an area if they were in reasonable danger. The function finally got its first use in the real world, but it appears it was by mistake.
A video shared by u/Joshalander in the r/TeslaLounge subreddit recorded the instance from his vehicle and said the incident took place in Austin this past weekend during the city’s F1 Race.
“Was charging around 6 AM this past Sunday in Austin before heading to the F1 race and heard a pop. Looked over and saw the new emergency drive-away feature in action. Genuinely felt bad for the dude when he got out and realized what happened, since he looked exhausted and only seemed to half-read the prompts.”
🚨 Here’s the first look at Tesla’s Emergency Drive Away function in action:
Apparently this driver accidentally enabled it and drove forward; you can see the Supercharger pull with the car.
Tesla said previously this would cost up to $25k if not used properly. https://t.co/B4qQRrsO6B
— TESLARATI (@Teslarati) October 28, 2026
Emergency Drive Away unlatches the Supercharger connector from the vehicle, but still causes damage to both the car and the Supercharger. Tesla has said that it will cost up to $25,000 in repairs to have everything fixed back to normal.
Additionally, the company said that if it were not used in an emergency situation, the driver of the vehicle who activated the Emergency Drive Away feature would be responsible for all repair costs.
Tesla constitutes the following situations as reasonable justifications for activating the feature:
- You face an immediate threat to your life or personal safety.
- You must leave the area immediately.
- Exiting the vehicle is unsafe.
- Unplugging the charge connector would unreasonably delay your departure or expose you to a risk to your personal safety.
After using the feature, Tesla requires the driver to schedule Service so the car can be inspected.
News
Tesla’s Cybercab battery design could make robotaxis even cheaper
Tesla built the Cybercab’s battery pack with spare room for a future switch to LFP.
Tesla built the Cybercab’s battery pack with empty space inside it on purpose, and the reason points to a cheaper robotaxi down the road.
Robert Sumpf, Tesla’s director of mechanical design engineering for battery modules and packs, said the extra room beside and beneath the Cybercab’s modules was left there so the company can move to lithium iron phosphate cells later. “So, we protected this pack to go to an even lower energy dense chemistry as we scale and need to bring LFP into the platform,” Sumpf said in a Cybercab deep dive with Munro Live.
The Cybercab runs on Tesla’s own 4680 cells with a nickel chemistry today. LFP cells store less energy for their size, so a straight swap would cut range. The reserved space lets Tesla add more LFP cells to make up the difference. In return, Tesla would get cells that cost less, run cooler and survive more charge cycles. LFP became the most used EV battery chemistry in the world last year.
Not all of that room was planned for a chemistry change. Lars Moravy, Tesla’s Vice President of Vehicle Engineering, said part of it exists because “we didn’t need as many batteries as we thought we did.” Tesla told Sandy Munro in early 2025 that it was targeting a Cybercab pack under 50 kWh with close to 300 miles of range.
The pack also breaks from the structural design Tesla used in some Model Y and Cybertruck builds. Instead of potting hundreds of cells into one block, the Cybercab uses four separate, individually sealed modules, so a bad module can be replaced without scrapping the whole pack. Sumpf was blunt about the older approach, giving the Model Y structural battery “a grade D” because it was hard to build and nearly impossible to repair. He estimated a fully structural pack gains about 10% more cell volume, but said “the issue is the service cost.”
That cost matters more for a car that rarely sits parked. Cybercab chief engineer Eric Earley said replacing an entire pack “before half a million miles is a killer on cost,” which is why remanufacturing and serviceability were built into the design from the start.
The same Munro Live tour produced Moravy’s admission that the Cybercab line at Giga Texas is now outpacing Robotaxi deployments, along with a look at the robotaxi’s unorthodox paint process. Tesla is aiming to deliver the first Cybercabs to outside customers by the end of 2026, though Elon Musk has said the vast majority will stay owned by Tesla and run as a transport service.
Sumpf did not give a date for an LFP version, name a cell supplier or say how a chemistry change would affect range. For now, the 4680 cars keep piling up: Texas DMV records from Tuesday list 544 Cybercabs authorized for Tesla’s Robotaxi fleet, more than the 507 Model Ys on the same roster for the first time.
Tesla Semi catches fire in California: what we know
Tesla’s ‘Emergency Drive Away’ function gets its first use in the real world
