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.
Tesla AI lead Ashok Elluswamy said this week that 24-hour Robotaxi service is close. Replying on X to a rider who wanted Cybercab trips all night, he wrote that the capability would arrive “next month or so” once “the next tech to merge on the v15 plan” is ready.
The comment landed on September 4, one day after Tesla opened public Cybercab rides in Austin. It is the clearest near-term timeline yet for overnight unsupervised operation. Tesla’s paid Robotaxi network currently runs from 6 a.m. to 10 p.m. seven days a week across Austin, Dallas, Houston, Miami, Orlando, and Tampa.
next month or so. the next tech to merge on the v15 plan will enable it.
— Ashok Elluswamy (@aelluswamy) September 4, 2026
That 16-hour window is shorter than the 6 a.m. to 2 a.m. schedule the company used for much of the prior year.
Elluswamy did not name the specific feature or say whether the change would apply first to purpose-built Cybercabs, the existing Model Y fleet, or both. He also offered no city-by-city rollout list. The link to Full Self-Driving v15 is nevertheless significant.
Tesla has described v15 as a step-change architecture with seven parallel improvement tracks and roughly ten times more parameters than earlier builds. Early versions of that software already operate on the Robotaxi fleet and contain about 40 percent of the planned gains.
By July 2026, the unsupervised fleet had logged more than 380,000 miles across six cities in two states with what the company called an impeccable safety record and no notable incidents caused by the vehicles themselves. Tesla has repeatedly argued that camera-based end-to-end neural networks, rather than extra sensors, are the core of the solution.
Overnight service would test that claim in lower-light conditions and would also raise vehicle utilization, a key variable for Robotaxi unit economics. The company has already begun using public Superchargers at night and is building dedicated Robotaxi charging sites.
Riders have asked why software must change if the cars already drive in the dark. The practical answer appears to be reliability and scale: Tesla has held back mass expansion until more of the v15 stack is merged, citing the need for higher confidence before putting thousands of unoccupied vehicles on streets around the clock.
If the next module arrives on the timetable Elluswamy sketched, 24-hour service could begin in October 2026 in at least some markets.
That would mark a shift from a daytime-bounded pilot to a service that can run whenever demand exists, including the late-night hours that have so far remained out of reach.
Tesla is beginning to roll out Full Self-Driving Supervised v14.3.9 with a new active safety layer that can take control even when the driver is operating the car manually.
Tesla AI said the software can activate FSD on the driver’s behalf when an imminent collision is detected and Automatic Emergency Braking may not be enough. It may also engage if the system detects heavy distraction or an accidental FSD disengagement.
FSD Supervised v14.3.9 starting to roll out shortly
This release includes a new active safety feature set: FSD Supervised can now activate on your behalf when an imminent collision is detected and Automatic Emergency Braking (AEB) may not be enough.
It may also engage if we…
— Tesla AI (@Tesla_AI) September 4, 2026
The capability is essentially Automatic Collision Evasion. However, unlike conventional AEB, which mainly applies the brakes in a straight line, this feature can use steering, braking, and acceleration together if the car calculates that stopping alone will not prevent impact and a safer path exists. The system may change lanes or move toward a shoulder when conditions allow, then continue driving after the immediate threat is handled rather than simply coming to a stop.
The intervention is meant as a last-resort safety net, not a replacement for attentive driving.
Tesla Full Self-Driving v14.3.7 early review: FSD saved me from an accident
Tesla’s own description still frames FSD as supervised assistance. Secondary reports on internal release notes say the feature can fire while the car is being driven manually if cabin-camera monitoring suggests the driver is not sufficiently attentive, such as reaching toward the back seat, or if FSD appears to have been turned off unintentionally.
After the emergency maneuver, the car is expected to alert the driver and request a return to manual control.
The safety case is straightforward. Many collisions happen in the last second because a driver is looking away, fumbles a control, or faces an obstacle that braking cannot fully solve. A system that can both recognize that AEB is insufficient and execute a coordinated evasive path can reduce those remaining high-severity events.
Re-engaging after accidental disengagement also addresses a practical failure mode: a small steering nudge that drops FSD at the worst moment. The advantage is a background safety net that uses the same vision stack already running in v14, instead of leaving the car solely to emergency braking once the driver is no longer in command.
The feature still depends on FSD being enabled and, according to reports, an active FSD purchase or subscription. It does not make the vehicle unsupervised. Drivers remain responsible, and Tesla has not published how often the system is expected to intervene or how it will handle false positives.
If the rollout is conservative and the false-alarm rate stays low, the update is a meaningful step: FSD is no longer only a feature the driver turns on. In the rare moments when disaster is already forming, it can step in.
Tesla launched the all-electric, steering wheel-less, and pedal-less Cybercab last night at a quiet and small event in downtown Austin, Texas.
The launch, which marked the beginning of unsupervised ride-hailing for Tesla’s Robotaxi platform with Cybercab, has already caught the attention of the National Highway Traffic Safety Administration (NHTSA) who has more questions.
NHTSA opened an Audit Query (AQ) into the Cybercab’s Federal Motor Vehicle Safety Standards (FMVSS) certification that Tesla gave the vehicle. Manufacturers self-certify vehicles much of the time to avoid excessive regulatory delays.
Tesla Cybercab interior, note the lack of steering wheel and pedals. (Credit: @niccruzpatane/X< /a>)
However, the agency needs more information; it said in a summary:
“On September 3, 2026, Tesla began commercial deployment with a small number of its Cybercab vehicles in Austin, Texas. Tesla notified the Agency that it certified those Cybercab vehicles as compliant with all applicable Federal Motor Vehicle Safety Standards (FMVSS). Tesla also notified the Agency that it plans to gradually expand commercial deployment of the Cybercab to include additional vehicles and locations.”
It also went on to state that the Cybercab lacks traditional automotive controls, which is a groundbreaking move. The process is entirely new to the NHTSA, which gives the agency some leverage to put Tesla’s launch under a microscope:
“The vehicles lack permanently attached, conventional manual controls, such as a brake pedal, gas pedal, steering wheel, and mirrors. NHTSA is opening this AQ to examine the process and technical data on which Tesla relied when certifying the Cybercab and related issues. Among other things, NHTSA will consider the extent to which Tesla’s certification depended on determinations that certain FMVSS are inapplicable to the Cybercab.”
Tesla has added 45 Cybercab units to its fleet of Robotaxi-enabled cars in Austin, according to public documents the company submitted to the State of Texas over the past week. Enabling this level of self-driving is something Tesla has worked toward for many years, and now that it is finally here, it seems more than reasonable that regulatory agencies will have some questions.
Many outlets might try to frame this as a negative, but it is truly an agency looking to gain more information about groundbreaking tech that Tesla has been developing for years.
In an effort to keep riders, pedestrians, and property safe, any and all data accumulated from these first days, weeks, and months of rides will likely be shared with the NHTSA to enable broader rollout strategies across the United States and more in the future.
Tesla Robotaxi will be a 24/7 service: here’s when
Tesla Full Self-Driving will now overtake manual driving to avoid disaster
