News
SpaceX begins installing Raptor engines on first Super Heavy booster
SpaceX has installed a Raptor engine on a Super Heavy booster prototype for the first time, defying expectations and setting the rocket up for two major tests as early as this week.
On Thursday, July 8th, SpaceX briefly filled Super Heavy Booster 3’s (B3) propellant tanks with benign nitrogen gas. The vehicle seemingly came to life for the first time that morning when it was spotted using its tank vents – a generally incontrovertible sign that the complex mechanical system that is a rocket is functional. Later that day, the public highway and beach adjacent to SpaceX’s launch site were briefly closed for what was expected to be an ambient pressure and/or cryogenic proof test.
Booster 3 never got to the cryogenic proof test – easily confirmed thanks to the frost that forms on most rockets’ exteriors as main tanks are filled with extremely cold liquid nitrogen. No such frost formed, no major venting occurred, and the road was only closed for the first two hours of a six-hour test window.
According to Next Spaceflight’s Michael Baylor, SpaceX did complete a “brief ambient proof” during that relatively short closure, though very little activity was visible during the test. Friday’s 14-hour test window was canceled the next morning, leaving SpaceX the rest of the weekend to prepare the first functional Super Heavy booster for its first truly challenging test – cryo proof.
Instead, late on Saturday, July 10th, SpaceX rolled Raptor 57 (R57) from build site to launch pad and began installing the engine on Booster 3 just a few hours later. Prior to Raptor 57’s installation, most prominent (albeit unofficial) voices in the SpaceX fan community anticipated no more than cryogenic proof testing for Booster 3 – no static fires, in other words.
However, it was fairly apparent that Super Heavy Booster 3 and the modified suborbital launch mount it was installed on were both outfitted for testing more complex than a cryo proof alone. Notably, B3 rolled to the pad with multiple labeled methane pressure vessels (COPVs), extensive plumbing, and autogenous pressurization control panels installed – all of which continued to be actively worked on after the booster was installed at the launch site.
While it’s technically not impossible to build a ground testing Starship prototype that’s capable of a wide variety of tests but never actually used to its full extent, doing so would be well out of character for SpaceX and make little sense in general. As such, it’s not a major surprise that SpaceX has now begun to install Raptor engines on Super Heavy Booster 3. What is surprising is that SpaceX is installing Raptor engines on a first-of-its-kind Super Heavy prototype before any fully integrated booster has completed cryogenic testing.
Based on Starship’s ~18-month test history, there is a real possibility Super Heavy B3 will fail during cryogenic proof testing. Even accepting that SpaceX’s testing processes and expertise have matured dramatically after dozens of Starship tests on the ground and in flight, the chance remains. In other words, SpaceX’s decision to begin installing Raptors on Super Heavy before ensuring structural and mechanical integrity implies some combination of unusual confidence in a prototype as unproven as Booster 3 and a distinct lack of concern at the prospect of losing at least two Raptor engines in a hypothetical test failure.
Knowing SpaceX and CEO Elon Musk’s goals for Raptor, the latter implication isn’t much of a surprise but it’s always interesting to have direct visual evidence that Raptor is, in fact, so cheap to build and easy to install that the minor effort and few days of possible delays required to reduce the risk of losing multiple engines just aren’t worth it.
As such, it’s now clear that Super Heavy Booster 3 will have at least one or two Raptor engines installed during its very first cryogenic proof test – currently no earlier than 12pm to 8pm CDT (UTC-5) on Monday, July 12th. Assuming SpaceX’s confidence is well-placed and Booster 3 passes its first cryogenic tests without issue, the real question now is how many Raptors will be installed and ignited during Super Heavy’s first static fire test?
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
