News
Elon Musk says SpaceX making good progress on Starship’s upgraded Raptor 2 engines
As is routine, SpaceX CEO Elon Musk has taken to Twitter to offer a few details about the status of Starship, its Raptor engines, and a few upgrades planned for both.
In mid-December, Musk revealed even more ambitious plans to upgrade Starship by stretching its propellant tanks and adding another three Raptor engines, potentially boosting the ship’s maximum thrust by 50% and substantially improving payload performance. These latest details are focused on an upgraded version of the Raptor engine and on additional changes to Starship’s structural design and assembly process.
According to Musk, as SpaceX continues to ramp up ground testing of the upgraded engine variant, “Raptor 2 now operates routinely at 300 bar main chamber pressure.” For context, on February 10th, 2019, just days after SpaceX began testing the first full-scale Raptor prototype ever completed, the engine briefly reached a main combustion chamber pressure just shy of 269 bar (3900 psi). That narrowly beat records set by Russia’s RD-270 and RD-180 engines, the latter of which is used on ULA’s Atlas V.
It took 18 months before Musk revealed clear proof that at least one Raptor prototype sustained such high chamber pressures over a minute or more of steady-state operations. The same engine peaked at an impressive 330 bar (~4800 psi), briefly producing 225 tons (~500,000 lb) of thrust and soundly beating out Russia’s never flown RD-701 engine, which crested 290-300 bar in testing. Another ~18 months after that milestone, Raptor isn’t quite operational in the sense of supporting orbital-class launches but the engine isn’t far from its first and has since supported dozens of Starship static fires and seven flight tests – five of which occurred in a period of just six months.
Already, despite the fact that Raptor 1 or 1.5 engines have yet to even attempt an orbital-class launch, SpaceX has almost entirely moved on to a new and improved variant known as Raptor 2. According to Musk, all Raptor ground testing at the company’s McGregor, Texas development campus is now focused on the new hardware, which reportedly features much cleaner plumbing and wiring. The biggest change to Raptor 2, though, is an almost 25% increase in maximum nominal thrust over Raptor 1/1.5 – from around 185 to 230 tons (408,000-507,000 lbf). That’s partially enabled by widening the ‘throat’ of Raptor’s nozzle, which sacrifices a small amount of efficiency for more power density. However, Raptor 2 also contains design improvements throughout to enable sustained, reliable operation at chamber pressures up to 300 bar – 10% higher than Raptor 1.5.
On October 24th, Musk subtly live-tweeted one of the first Raptor 2 static fires, revealing that the engine reached a chamber pressure of 321 bar (~4650 psi) and briefly produced around 245 tons (~540,000 lbf) of thrust before destroying itself. Now, a little over two months later, Musk says that Raptor 2 prototypes are routinely operating at 300 bar without major issues, meaning that they can ignite and safely shut down after burning for several minutes at those pressures. In theory, given that 300 bar is Raptor 2’s targeted chamber pressure at max thrust, that means that the engine is now “routinely” operating at the level SpaceX wants and needs to take Starship to the next level.
It’s likely that one or several months of work remain before SpaceX can begin qualifying the first Raptor 2 engines (or, more importantly, hypothetical Raptor 2 Vacuum or Boost variants) for the first Starship or Super Heavy prototypes designed for the new engine. Nonetheless, the rapid progress SpaceX has made in the first few months of Raptor 2 testing is extremely encouraging.
Tesla has reached a notable benchmark in its autonomous driving program after its Robotaxi fleet surpassed one million miles of unsupervised operation. The company made the announcement during its Cybercab event in Austin on September 3.
Tesla Vice President of AI Ashok Elluswamy told attendees he was happy to report the fleet had achieved one million miles of unsupervised Robotaxi operation as a testament to safety.
The new total marked a sharp increase from the 380,000 unsupervised miles Tesla disclosed during its second-quarter 2026 earnings update in late July.
In roughly six weeks, the company added about 620,000 miles. That acceleration followed Tesla’s decision to remove in-vehicle safety monitors from most of its operations outside the San Francisco Bay Area.
Credit: Tesla
Tesla first launched Robotaxi service in Austin in June 2025 with safety drivers present. It later began fully unsupervised rides and expanded into Dallas, Houston, Miami, Orlando, and Tampa. The San Francisco Bay Area remains the exception, where a safety monitor still rides in the vehicle under California permitting rules.
The company has not released a city-by-city breakdown of the one million unsupervised miles.
The milestone arrived as Tesla began offering public Cybercab rides in Austin. The purpose-built vehicle has no steering wheel or pedals and is designed only for autonomous ride-hailing. Production versions joined the existing fleet of modified Tesla vehicles already operating in the service.
Tesla’s unsupervised mileage is growing at a double-digit weekly rate according to earlier company comments, yet its fleet size remains modest compared with established competitors. Waymo has accumulated more than 200 million fully autonomous rider-only miles. Tesla has described its own unsupervised operations as having recorded zero notable incidents in the period leading up to the July update.
The one-million-mile figure reflects Tesla’s shift from supervised testing to broader driverless service in multiple states. It also highlights the company’s strategy of using both existing Model Y vehicles and the new Cybercab to scale its network.
Credit: Tesla
Whether the rapid recent growth continues will depend on further city expansions, regulatory approvals, and the performance of the purpose-built Cybercab in everyday paid rides. Tesla has not specified how many of the latest miles involved the new vehicle versus the rest of the fleet.
The announcement underscores Tesla’s progress toward a larger robotaxi network while illustrating the remaining gap in total autonomous experience relative to longer-operating rivals.
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 crosses major Unsupervised Self-Driving milestone
Tesla Robotaxi will be a 24/7 service: here’s when
