News
SpaceX CEO Elon Musk posts uncut Raptor, drone videos of Starhopper’s flight test debut
Some two hours after Starhopper’s inaugural untethered flight, SpaceX CEO Elon Musk took to Twitter to post an uncut video showing the ungainly rocket’s launch and landing from the perspective of both a drone and Starhopper’s lone Raptor engine.
As noted by commenters, Starhopper’s first flight also marks perhaps an even more fascinating milestone: it’s technically the first launch ever of a full-flow staged-combustion (FFSC) rocket engine. Whether or not the development hell Raptor required is or was worth it to SpaceX, the company has become the first and only entity on Earth to develop and fly a FFSC engine, beating out the national space agencies of both the United States and Soviet Union, both of which built – but never flew – prototypes.
Instead of inexplicably shelving a mature prototype development and test program, SpaceX iterated through several subscale Raptor prototypes, test-fired the engines for more than 1200 seconds total, used that data to design and build full-scale Raptors, and finally sped into a hardware-rich test campaign with six (soon to be seven) new engines. After SpaceX settled on a full-flow staged-combustion cycle and methane/oxygen (methalox) propellant, Raptor conducted its first full-scale tests all the way back in 2014, performing preburner flow and ignition tests at NASA’s Stennis Space Center.
Two years and many additional subcomponent tests later, SpaceX successfully performed the inaugural static fire test of its first completed subscale Raptor, a huge milestone for any rocket engine. In the 12 months following its first static fire (September 2016), SpaceX performed dozens of static fire tests with several subscale engines, putting the new propulsion system through >1200 seconds of combined testing.
A year after that, SpaceX was still testing subscale engines but the first full-scale Raptor engine was just a few months away from completing assembly in Hawthorne and heading to McGregor to kick off full-scale static fire testing. Indeed, four months after CEO Elon Musk’s September 2018 update, Raptor serial number 01 (SN01) shipped to Texas in late January and successfully ignited for the first time on February 3rd. SpaceX’s finalized full-scale Raptor engine is designed to produce more than 2000 kN (450,000 lbf, 200 tons) of thrust at full-throttle.
Since that inaugural ignition, SpaceX’s propulsion team – perhaps to their detriment, under orders from Musk – pushed SN01 and several of its successors to their limits as quickly as possible, resulting in severe, irreparable damage in several cases. On the other hand, the no-holds-barred, ‘hardware-rich’ (i.e. destructive) test program has allowed SpaceX to relatively quickly solve several major bugs that prevented the engine from passing longer test fires.
Raptor SN05 was originally expected to support Starhopper’s first flight(s) but had to be passed up after suffering damage in one of its final June 2019 acceptance tests. Raptor SN06 became the first engine – likely thanks to tweaks afforded by data gathered from its failed brethren – to pass all of those acceptance tests, leading to its eventual installation on Starhopper in early July.
Raptor’s impressive development culminated on July 25th with the engine’s first untethered flight while attached to Starhopper, a 9m-diameter (30 ft) low-fidelity prototype that is more or less a mobile test stand for the next-generation SpaceX engine. Raptor is now the only FFSC engine in history that has powered a flight-capable vehicle’s launch and landing, even if said flight featured an apogee of just 20-30 meters (65-100 ft).
“In full-flow staged combustion (FFSC), even more complexity is added as all propellant that touches the engine must necessarily end up traveling through the main combustion chamber to eke every last ounce of thrust out of the finite propellant a rocket lifts off with. As such, FFSC engines can be about as efficient as the laws of physics allow any given chemical rocket engine to be, at the cost of exceptional complexity and brutally difficult development.“
SpaceX delays Starhopper’s first flight a few days despite Raptor preburner test success
For more on what exactly makes full-flow staged-combustion engines uniquely capable and challenging to develop, the subject has been covered at length in past Teslarati articles.
According to Musk, the next major challenge facing Starhopper and (presumably) Raptor SN06 is far more ambitious 200-meter (650 ft) hop and flight test that could happen as soon as the first half of August.
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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 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.
News
Tesla integrates Grok Bot into its vehicles for the ultimate personal assistant
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.