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SpaceX Starship aborts Raptor engine test, briefly catches fire
Update: On March 15th, SpaceX got within milliseconds of Starship serial number 11’s (SN11) first Raptor engine test but suffered an abort just before full ignition, briefly leaving the rocket on fire.
Around 12:26 pm CDT, after an otherwise nominal static fire flow, Starship SN11 momentarily ignited one or two of its three Raptor engines’ preburners, referring to a central component that burns cryogenic liquid propellant into gas that’s ready for combustion. As with all preburner tests, intentional or otherwise, the end result looked a bit like a weak static fire and produced a small but visible amount of flame and thrust. Unlike intentional preburner tests, the static fire abort seemingly ignited something hidden inside Starship SN11’s and appeared to burn for at least another 30-40 seconds.
Raptor has proven itself to be an extremely durable engine, up to and including surviving visible onboard fires during actual Starship flight tests. Nevertheless, depending on the source of SN11’s post-abort fire and what it may or may not have burned or damaged, it’s no surprise that SpaceX ended testing for the day instead of quickly trying again, which it’s done several times prior. If the fire was largely harmless, SpaceX has already distributed notices suggesting a second attempt could happen as early as 6am to 12pm CDT (UTC-5) on Tuesday, March 16th. If more time is needed, SpaceX has the rest of the week to conduct any necessary repairs or swap out SN11’s Raptor engines.
Public documents show that SpaceX has plans to static fire and launch its latest Starship prototype within a two-day period that could begin later today.
SpaceX shipped Starship SN11 from its Boca Chica, Texas rocket factory to test and launch facilities a mile down the road on March 8th, less than five days after Starship SN10 exploded minutes after touchdown. The very next day, SpaceX completed ambient-temperature proof testing, filling Starship with benign nitrogen gas to check for leaks and verify system health. Two days after that, Starship SN11 appeared to complete a several-hour cryogenic proof test – swapping nitrogen gas for its supercool liquid form – without issue.
Despite the seemingly successful ‘cryo proof,’ something prevented a subsequent static fire test planned on March 12th before any attempt could be made, delaying the next attempt until after the approaching weekend. An agreement between SpaceX, Cameron County, and the state of Texas currently prevents road closures (and thus rocket testing) on weekends falling between Labor Day and Memorial Day, rules meant to preserve some level of public access to Boca Chica Beach.
As a result, unless SpaceX is already ready to launch (it has waivers for three such weekend closures for launch attempts), the company has to wait until Monday even if a minor issue fixable in hours or a day or so scrubs Friday test plans. While inconvenient, it’s worth noting that the existence of that public beach and the strong regulations that protect its public domain is likely one of the only reasons the general public can still get as close as they can to SpaceX’s Boca Chica ‘Starbase’.
For whatever reason, that road closure agreement does still mean that SpaceX will (in theory) be able to test and launch any day of the week from May 31st to September 6th, save for a few holidays, effectively boosting the number of opportunities by 40% for those 14 weeks. Until then, SpaceX is doing everything it can to take full advantage of the five days a week it is allowed to test Starship prototypes. N
Notably, although Starships SN8 and SN9 both hit a few weeks of technical and regulatory snags while preparing for their high-altitude launch attempts, SpaceX has been gradually speeding up that process over time. Starship SN10, the first prototype of its kind to land in one piece, took just 33 days to go from pad arrival to liftoff and spent just 8 days between its first static fire and launch attempts. The same feats took Starship SN8 77 and 50 days, respectively, with SN9 splitting the difference at 43 days from transport to liftoff and 28 days between its first static fire and launch attempts.
Road closure requests, a safety warning for residents, and a Temporary Flight Restriction (TFR) filed with the FAA all suggest that SpaceX’s current plan is to attempt Starship SN11’s first triple-Raptor static fire between 6am and 12pm CDT on Monday, March 15th. If that test goes almost perfectly, SpaceX wants to turn the rocket around for a 10 km (6.2 mi) launch attempt on Tuesday, March 16th – the very next day. Given the past performance of high-altitude Starship prototypes, that target is decidedly ambitious and likely to incur delays, but it still reveals the true scope of SpaceX’s goals even at this early stage of development.
If Starship SN11 does manage to launch within a few days of its first static fire attempt, SpaceX would still crush SN10’s 33-day record by a factor of three. Stay tuned for updates on Monday’s possible Starship static fire and rapid Tuesday turnaround attempt
Investor's Corner
Tesla Optimus Gen 3 shows off a cleaner, factory-ready design in new app discovery
Renders hidden inside Tesla’s Android app show Optimus Gen 3’s design before any official reveal.
![Tesla Optimus Gen 3 [Credit: Tesla]](https://www.teslarati.com/wp-content/uploads/2026/03/tesla-optimus-gen3-diner.jpg)
Tesla may have accidentally given a first look at its newest Optimus Gen 3 humanoid robot when photos were found in the Tesla smartphone app.
Design files tucked inside a recent Android version of the Tesla app appear to show the third generation humanoid robot next to the older Gen 2.5 prototype. The assets were extracted from the app package by Tesla community member @wholemars, who posted the renders on X late Tuesday night before deleting them. The Tesla Newswire reshared the side by side comparison on Wednesday, and the images have circulated widely since.
Tesla Optimus Gen 2.5 vs Gen 3 comparison via @WholeMars on X
The files are labeled “gen3” and were built as models for Tesla app’s own interface, as validated directly by Grok to be official.
The comparison shows a robot that looks built for a factory line rather than a lab bench. Gen 2.5’s exposed mechanical linkages and gold plating on the knees and shins are gone. In their place, Gen 3 uses matte black fairings on the lower legs, paired with a more contoured champagne gold body. Flexible covers now seal the joint where the torso meets the upper thighs, keeping bearings and moving parts sealed from debris and unnecessary contact.
The body panels fit more tightly, and the hands, which Tesla has said carry 22 degrees of freedom, look far more refined than those on earlier units.
This most recent leak fills a gap Tesla has left open for most of the year. Elon Musk said on March 31 that Optimus 3 was walking around but needed “some finishing touches” before it could be shown, a delay Teslarati covered when Tesla missed its first quarter reveal target. Musk later said Tesla would hold the design back until closer to production, partly to keep competitors from copying it. No reveal date has been announced.
The app itself has been preparing for Optimus for months. In July, code in the Tesla app pointed to a dedicated robot phone key, a consent screen for collecting video and spatial data while Optimus works inside a home, and an alert system for low battery and mechanical faults. Finished 3D models of Gen 3 suggest the interface owners will eventually use is moving past placeholder code toward something Tesla intends to ship.
Manufacturing is moving in parallel. Tesla tore out the original Model S and Model X lines at Fremont this summer to make room for Optimus production, with a planned capacity of one million robots a year. At Giga Texas, the steel frame of a dedicated Optimus factory is nearing completion ahead of a targeted 2027 start, with Musk pointing to an eventual output of 10 million units annually.
News
Tesla Semi lands the biggest electric truck deal in U.S. history
Tesla leads a record 2,500 truck order, but not every truck will be a Semi.
Tesla has landed the largest electric truck order in U.S. history. ZET SCALE, a new alliance of shippers and carriers, named Tesla its primary manufacturer on Tuesday for an initial order of 2,500 electric Class 8 trucks. The deal alone would nearly double the number of electric heavy trucks operating in the country.
According to the press release from Catalyst Mobility, the nonprofit formerly known as CALSTART, Kenworth, RIDE and Volvo were also selected as secondary manufacturers that carriers can pick if their operations call for it. No split between the four brands has been published, so the exact number of Semis in the order is not yet known.
Tesla was selected as the primary OEM for the largest electric Class 8 order in the US by ZET SCALE, a new shippers’ alliance
With 2,500 Semis on order, this will double the entire US electric Class 8 fleet
We’re serious about scale, and ZET SCALE is too!… pic.twitter.com/IiTAdzgken
— Tesla Semi (@tesla_semi) September 22, 2026
Tesla won the top slot through a competitive request for proposals. The alliance, which Catalyst Mobility runs with the Smart Freight Centre, scored bidders on price, range, charging capability and production capacity. Pooling freight demand from founding shippers, including Microsoft and PepsiCo, let every truck maker bid lower than it would for a single fleet. “The Tesla Semi is designed for lower cost per mile operations than diesel,” said Dan Priestley, director of the Tesla Semi program, as noted in the press release.
The financing is built to pull in carriers who have avoided electric trucks. ZET Financial is issuing the purchase order for all 2,500 units and will place them with fleets through a fair market value lease. The trucks will be deployed over the next few years across 10 freight hubs in Los Angeles, Stockton, Bakersfield, Seattle and Tacoma, Houston, Dallas, San Antonio, Chicago, Atlanta, and the Newark and New York area. ZET SCALE says the first order is only the opening round, with a longer term goal of 10,000 trucks or more.
Even if Tesla ends up with only a majority share, it would still be the biggest Semi deal to date. Einride’s 500 unit order in August was the previous record, and WattEV’s 370 truck order in May was the largest California deal at the time. Einride’s CEO has since said he expects all 500 trucks delivered by the end of 2027.
The announcement lands two days before Tesla formally inaugurates its Semi factory in Nevada on September 24. The 1.7 million square foot plant sits next to Gigafactory Nevada’s 4680 cell lines and is designed for 50,000 trucks a year.
Tesla has expanded Grok from an in-car chatbot into a hands-free work assistant. On September 22, Tesla officially launched Grok Bot capability, confirming that drivers can now manage email, calendars, files, chats, and tasks by voice and then hand more ambitious errands to the AI-fueled productivity cheat code.
Grok itself is built by xAI. The new car features split into two layers: Connectors link Grok to outside accounts. Grok Bot, currently limited to SuperGrok Heavy subscribers, can complete multi-step tasks such as placing a usual coffee order, booking a reservation, or scheduling an appointment. It truly puts the driver in a nearly complete hands-free driving and productivity setting, with ironically the only task truly requiring your hands being to touch the “Start Self-Driving” button.
We were granted access to Grok Bot’s Tesla integration a few weeks back, and we’ve been able to do a handful of things with it. On a handful of occasions, we’ve used it to order food and have it ready for pickup slightly later into the evening; we’ve managed to pick up groceries after a day of errands with Grok Bot, and outside of the car, it’s helped with budgeting and even my fantasy football draft.
We’ve been using @Grok Bot in Tesla for a few weeks after gaining Early Access, which we thank the awesome engineers for
Grok Bot makes things much easier across your entire life. From the Tesla, I’ve used it to place pickup orders for my Fiancée and I, we’ve ordered groceries… https://t.co/ZJSLieG1s5
— TESLARATI (@Teslarati) September 22, 2026
Tesla shows another way to utilize it: in their demo, a driver says “Hey Grok,” asks the assistant to check an inbox, and hears that a message concerns a weekend reservation. Grok then scans the calendar, reports no conflicts, and confirms the Tahoe trip is clear. It can also add check-in details to a road-trip itinerary. The point is not novelty chat. It is keeping eyes on the road, or on Full Self-Driving, while the car handles the paperwork of a trip:
.@Grok in your Tesla can now do meaningful work for you
With Connectors, you can manage your inbox, clean up your calendar, or talk through existing files/chat/tasks – all hands-free pic.twitter.com/W1LuybQh0P
— Tesla (@Tesla) September 22, 2026
This Grok rollout is not a gadget add-on as much as it is Tesla’s thesis in software form: the car should stop being a machine you operate and start being a room you occupy.
Connectors and Grok Bot treat the cabin as an office that happens to move, and that has truly been Tesla’s intention for years now. The car has slowly become an extension of a home more than a vehicle. Inbox, calendar, groceries, takeout, and reservations become voice work, not dashboard chores that you need to do before you get in your car.
Responsibility shifts from the driver to the stack, and as many Tesla owners rely on FSD for travel, Grok Bot now handles the monotony of dinner reservations or appointments.
![Tesla Optimus Gen 3 [Credit: Tesla]](https://www.teslarati.com/wp-content/uploads/2026/03/tesla-optimus-gen3-diner-80x80.jpg)
Tesla Optimus Gen 3 shows off a cleaner, factory-ready design in new app discovery
Tesla Semi lands the biggest electric truck deal in U.S. history
