News
SpaceX is building Starship’s first orbital-class booster at a breakneck pace
Within the last week, SpaceX’s South Texas Starship factory appears to have kicked things into high gear and are now assembling the first orbital-class Super Heavy booster prototype at a breakneck pace.
While the assembly of the Super Heavy known as Booster 4 (B4) wasn’t too dissimilar to what CEO Elon Musk described as a “very hard” build of Booster 3 up to last week, work on the rocket has visibly accelerated. Since January 2020, the process of building Starships and Super Heavy boosters has been fairly simple. Both onsite and offsite, raw materials (mostly sheet steel) are cut, bent, and welded into relatively small parts that then make their way to (or around) Boca Chica by truck, forklift, or crane.
With the help of jigs and good amount of automation, the resulting hardware is then welded together to form domes, header tanks, transfer tubes, tank barrels, flaps, and more. Once subassembly is complete, those integrated rocket sections are reinforced with stringers, ribs, and baffles and outfitted with mechanisms, hardpoints, brackets, plumbing, and more. Finally, final assembly – better known as stacking and by far the most visible step – can begin and technicians stack each of those premade segments on top of each other to form a complete Starship or Super Heavy.
While part fabrication and subassembly integration take weeks or months on their own, those earlier steps can be done concurrently, meaning that SpaceX can prepare sections for several different ships and boosters at the same time. For the last six or so months, at any given moment, SpaceX has had 40-60+ rings in work as part of 15-20+ different ring ‘sections’ visible all across Starbase.
Respectively, each Starship and Super Heavy booster require 20 and 36 rings apiece, while each of the propellant storage tanks SpaceX itself is building for the rocket’s first orbital launch pad require 12-15. All told, SpaceX usually has a combination of around 3-5 ships, boosters, and GSE tanks in some stage of assembly. Unsurprisingly, some assembly tasks are harder than others and building the first in a series of prototypes has almost invariably taken far longer than building those that follow.
Booster 3 Booster 4 LOx tank start May 20th July 16th LOx tank finish June 18th July 30th CH4 tank start June 24th July 28th CH4 tank finish June 27th July 29th Final stack June 29th Aug 1st?
In that sense, it’s not a huge surprise that SpaceX’s Booster 4 assembly has quickly surpassed the pace set with Booster 3 less than a month earlier. SpaceX began stacking Super Heavy B3 around May 20th, starting with the rocket’s aft liquid oxygen (LOx) tank. Five separate stacks are required to turn the LOx tank’s 23 steel rings into a single structure – a process that took SpaceX about a month with Booster 3.
Booster 3 methane (CH4) tank assembly began a few days after the LOx tank’s completion but proceeded far more quickly, wrapping up just a few days later. Two days after that, those two tank sections were then mated and welded together to complete Booster 3’s full ~65m (~210 ft) tall airframe.
Now, just four weeks after Booster 3 was rolled to the launch pad for proof and static fire testing, Super Heavy Booster 4 is well on its way to reaching its full ~65m height almost twice as quickly. With work beginning around July 16th, B4’s oxygen tank is now just missing an (extremely complex) engine section and the booster’s methane tank was stacked to completion – 13 rings tall – in less than two days. That leaves SpaceX’s first potentially flightworthy, orbital-class Super Heavy booster just two stacks away from completion less than two weeks after its assembly began.
If SpaceX can sustain that pace for another few days, Booster 4 assembly will be the fastest of any full-height prototype ever built at Starbase, most of which have been Starship prototypes that are half to about three quarters the size of Super Heavy.
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
