News
SpaceX’s repaired Starship booster survives back-to-back cryoproof tests
SpaceX’s upgraded Starship booster has completed a second and third cryogenic proof test in rapid succession after undergoing repairs to fix damage suffered during the first round of testing.
Testing began almost immediately after SpaceX rolled the repaired Super Heavy booster back to the orbital launch site (OLS) on May 6th. After a quick installation on the pad’s stool-like launch mount and another day of systems checks and integration, Booster 7 charged headfirst into its first post-repair cryoproof on May 9th.
Instead of cautiously feeling out the repaired plumbing and header tank over a series of small tests, SpaceX immediately performed a full cryogenic proof (cryoproof) and filled Booster 7 to the brim with about 3000 tons (~6.6M lb) of liquid nitrogen (LN2) or a combination of LN2 and liquid oxygen (LOx). Standing about 67 meters (~220 ft) tall and 9 meters (~30 ft) wide, it took about two hours to fully fill Super Heavy’s tanks with the equivalent of one and a half Olympic swimming pools of cryogenic liquid.
As always, that liquid (well below –320°F or –196°C) rapidly chilled the booster’s 4mm (~0.16″) thick steel tanks to cryogenic temperatures, which then froze moisture directly out of the humid Texas air, coating almost all of Super Heavy’s exterior with a layer of frost and ice.
SpaceX began detanking Booster 7 soon after the fill process was completed. Thanks to plenty of insulated plumbing and well-insulated ground storage tanks, SpaceX is able to recover nearly all of the LN2 and LOx used during cryoproof testing, which helps avoid the hundreds of semi-truck delivers that would otherwise be required to replenish the tank farm after even a single test.
As if to demonstrate that, SpaceX proceeded to put Booster 7 through a whole new cryogenic proof test just two days later, on May 11th. Once again, Super Heavy was fully loaded with thousands of tons of liquid nitrogen and oxygen. Unlike Cryoproof #2’s immediate detank, SpaceX – judging by the frost levels – kept Booster 7 topped off for a good hour before detanking.
In a last-minute surprise, after fully detanking B7 at the end of Cryoproof #3, SpaceX refilled the booster’s liquid oxygen tank with a few hundred tons of LN2 or LOx. Once the rocket’s thrust section reached some degree of thermodynamic equilibrium, SpaceX remotely retracted and reconnected the orbital launch mount’s Super Heavy umbilical. The launch mount umbilical or ‘quick disconnect’ is responsible for connecting Super Heavy to the pad’s gas supplies, propellant storage, power, and communications. The test SpaceX completed after Cryoproof #3 may have been a rough simulation of one scenario Starship could easily face: a post-ignition launch abort. In other words, if an orbital Starship launch was aborted just before liftoff but after quick-disconnect retraction, could it quickly reconnect to the booster with zero human intervention?
In a scenario where a QD failed to reattach to a fully-fueled Super Heavy after a launch abort, the odds of a catastrophic fire or explosion would immediately shoot up to near-certainty. In moderate quantities, simultaneously venting gaseous methane and oxygen from the same rocket is risky but manageable. Venting hundreds – let alone thousands – of tons while trapped on the ground would amount to creating a multi-hour fuel-air bomb just waiting for a spark. Multiple Starship prototypes (SN4, SN10) have already been destroyed in part by the flammability of methane gas.
Combined with the completion of two full cryogenic proof tests in less than two days, it appears that Super Heavy B7’s repairs were extremely successful. Had the first post-repair cryoproof not gone more or less perfectly, it’s hard to imagine that SpaceX would have attempted or completed an almost identical test two days later. If the second cryoproof hadn’t been nearly perfect, it’s even harder to imagine that SpaceX would have accepted the risk involved in detaching Booster 7’s umbilical during the same test window.
On May 12th, SpaceX’s main pad crane attached a lift jig to Super Heavy B7, implying that it will likely be removed from the orbital launch mount in the near future. If the repaired booster aced its tests, SpaceX’s next step would likely be Raptor engine installation and the start of static fire testing. It’s unclear if SpaceX wants to install all 33 engines at once or begin with a small handful. It’s also unclear if SpaceX will return Booster 7 to Starbase’s production facilities to finish Raptor, heat shield, grid fin, and aerocover installation.
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
