News
SpaceX Starship booster survives record-breaking 31-engine static fire
SpaceX’s Starship rocket has survived a record-breaking engine test – potentially the most powerful static fire in the history of rocketry.
According to CEO Elon Musk, Super Heavy Booster 7 (B7) ultimately ignited 31 of its 33 Raptor engines. One engine was manually disabled “just before” the static fire, while the other faulty engine automatically shut down while attempting to ignite. The other 31 Raptors, however, completed a “full duration” static fire that lasted about five seconds. Musk says that even with two engines disabled, those that remained were “still enough…to reach orbit” – an excellent result despite the static fire’s imperfections.
Most importantly, Super Heavy Booster 7 survived the test without catching fire, exploding, or popping its tanks. To partially counteract the thrust of its Raptor engines, the rocket’s tanks were filled with some 3000 tons (6.6M lbs) of liquid oxygen and methane propellant. The stool-like orbital launch mount (OLM), which also survived the test in one piece, held Starship down with 20 clamps to counteract any remaining thrust. From SpaceX’s perspective, the fact alone that its only orbital-class Starship launch site survived the ordeal is likely enough for it to consider the static fire a success. But the test was much more than that.
The update that's rolling out to the fleet makes full use of the front and rear steering travel to minimize turning circle. In this case a reduction of 1.6 feet just over the air— Wes (@wmorrill3) April 16, 2024
Incinerating rocket records
Despite losing two Raptors, SpaceX still broke the all-time record for the number of rocket engines ignited simultaneously. That record was held by the Soviet N1 rocket, which launched four times with 30 NK-15 engines in the late 1960s and early 1970s. None of its test flights were successful, but N1 still set the record for the most thrust produced by a single rocket, generating up to 4500 tons (9.9M lbf) of thrust at liftoff.
Neither SpaceX nor CEO Elon Musk has confirmed it, reducing the odds that Super Heavy Booster 7 broke that historic thrust record. But it certainly could have. Each Raptor 2 engine can generate up to 230 tons (507,000 lbf) of thrust at sea level. Raptor is theoretically designed to throttle as low as 40%, or 92 tons (~200,000 lbf) of thrust. With 33 engines operating nominally at their minimum throttle setting, Super Heavy would have produced 3036 tons (~6.7M lbf) of thrust during today’s static fire – not a record.
For 31 Raptors to break N1’s thrust record, the average throttle setting would have had to be around 64% or higher – far from unreasonable. From a data-gathering perspective, a full-thrust static fire would be the most valuable 33-engine test SpaceX could attempt, but it would also be the riskiest and most stressful for the rocket and pad.
Former SpaceX executive Tom Mueller says that SpaceX broke N1’s record. Mueller is effectively the father of the Raptor engine, and likely still gets information straight from SpaceX engineers he used to work with. Still, one would expect SpaceX itself to proudly confirm as much if a rocket it built became the most powerful in history.
The most powerful rocket test in history?
Whether or not Starship became the most powerful rocket in history, it has likely become the most powerful rocket ever tested on the ground. The first stage of Saturn V produced around 3400 tons (7.5M lbf) of thrust during its first sea-level static fire in 1965. Likely contributing to its failure, N1’s booster was never static-fired. Other powerful rockets like the Space Shuttle and SLS use or used a combination of solid rocket boosters and liquid engines that cannot be tested together on the ground.
Unless SpaceX’s goal was a minimum-throttle static fire, Starship’s 31-Raptor static fire likely beat Saturn V’s record to become the most powerful ground test in the history of rocketry.
SpaceX’s next steps
While the 31 that did ignite appeared to perform about as well as SpaceX could have hoped, the two engines missing from February 9th’s historic Starship static fire have probably complicated the company’s next steps. To be fully confident in Starship’s ability to launch and fly a safe distance away from the launch site, SpaceX would likely need to complete a full 33-engine test. Meanwhile, Starship can’t fly until the Federal Aviation Administration approves a launch license, and the FAA could be stodgy enough to deny SpaceX a license without a perfect 33-engine static fire.
Alternatively, the FAA may accept that Starship could still safely launch and reach orbit while missing several Raptors. SpaceX could also guarantee that it will only allow Starship to lift off if all 33 engines are active, in which case a second 33-engine static fire attempt may not be necessary.
If SpaceX is happy with Booster 7’s 31-engine test results and isn’t too put off by any pad damage the test may or may not have caused, it will likely focus on finishing Starship 24. Ship 24 will then be transported back to the pad and reinstalled on top of Booster 7. SpaceX may choose to conduct another wet dress rehearsal or a static fire with the fully-stacked Starship, but it may also deem additional testing unnecessary.
Once all those tasks are completed, Ship 24 and Booster 7 will be ready to support Starship’s first orbital launch attempt. Prior to February 9th’s static fire, SpaceX CEO Elon Musk and COO/President Gwynne Shotwell agreed that Starship’s orbital launch debut could happen as early as March 2023. After today’s test, a March 2023 launch may be within reach.
Rewatch Super Heavy Booster 7’s historic static fire below.
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
