News
SpaceX Starship fires up Raptor Vacuum engine twice in one hour
After weeks of exceptionally cautious buildup, SpaceX’s first orbital-class Starship prototype has repeatedly broken new ground tests in the first few hours of its first static fire test window.
SpaceX first installed Starship S20 on one of two suborbital launch and test stands more than two months ago. After almost six weeks of largely invisible work, longer than any other new Starship prototype has spent inactive at Starbase launch facilities, Ship 20 came to life for the first time during a ‘pneumatic proof’ test completed on September 27th. Two days later, put the Starship through a complex cryogenic proof test, loading supercool liquid nitrogen instead of ambient-temperature gas and simulating the thrust of six Raptor engines with hydraulic rams.
According to CEO Elon Musk, Ship 20 passed its first ‘cryoproof’ without issue, opening the door for static fire testing with real methane and oxygen (LCH4/LOx) propellant and Raptor engines. However, for unknown reasons, it would ultimately take SpaceX more than three weeks of additional work to prepare Starship S20 for its first engine-involved test.
On October 19th, near the end of a seven-hour test window, Starship S20 sort of fired up for the first time, completing what is known as a preburner test. Effectively the first half of static fire test without full ignition, it was nevertheless the first time a Raptor Vacuum engine was operated on a Starship prototype. Originally, based on road closures scheduled with Cameron County, Texas, that preburner test and associated static fire testing was initially scheduled to begin as early as Friday, September 31st.
SpaceX continued to file for and cancel closures throughout the next week, culminating in a few local residents receiving a routine safety notice about a possible test on October 13th. That attempt was canceled soon after and SpaceX ultimately distributed alerts for tests on October 14th and October 18th. Ship 20’s first preburner test was completed on the 19th, followed by another soon-to-be-rescinded notice on the 20th.
Finally, after perhaps the windiest road yet for a Starship from cryoproof to static fire, Starship S20 sailed through a static fire test flow on October 21st and ultimately fired up for the first time ever at 7:16 pm CDT (00:16 UTC). In perfect opposition to weeks of unprecedentedly slow testing, Starship S20 not only completed its first true static fire early in the test window, but it completed the first on-vehicle static fire of a Raptor Vacuum engine and then, just over an hour later, performed a second static fire – this time simultaneously igniting both a Raptor Vacuum and Raptor Center (sea-level-optimized) engine. Aside from also marking the first time that two Raptor variants have been simultaneously fired on the same vehicle, Starship S20’s two-test surprise was technically the fastest back-to-back static fire SpaceX has ever completed, beating Starship SN9 by about 15 minutes.
Back in January 2021, SN9 completed an unprecedented three back-to-back-to-back Raptor static fires in less than 100 minutes as part of what Musk described as “[a day] about practicing Starship engine starts.” SN9 ultimately completed two of those tests in 75 minutes, setting a niche but still impressive turnaround record. Starship S20, however, managed two static fires in 62 minutes on October 21st.
With any luck, Ship 20’s unexpected first-test milestones will mark the start of a more energetic period for the orbital-class prototype, potentially building up to the first Starship static fire with more than three Raptors and the first test with all six engines installed. Super Heavy Booster 4 is also well overdue for its own proof and static fire test campaign, virtually all of which will be new territory for SpaceX.
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
