News
SpaceX fires Falcon Heavy’s 27 booster engines ahead of “most difficult launch ever”
For the third time ever, SpaceX has successfully performed a critical static-fire test of an integrated Falcon Heavy, briefly igniting all 27 of its Merlin 1D engines to verify the health and readiness of the rocket.
Per SpaceX’s official confirmation, a “quick-look” inspection of static fire telemetry has indicated that the company’s Falcon Heavy rocket is ready for its second launch in less than three months, a milestone that could also allow both flight-proven side boosters to tie SpaceX’s own record for booster turnaround. Falcon Heavy Flight 3 is now scheduled to launch the US Air Force’s Space Test Program 2 (STP-2) mission no earlier than 11:30 pm ET (03:30 UTC), June 24th. According to SpaceX CEO Elon Musk, the mission will unequivocally be the company’s “most difficult launch ever”.
Coincidentally, on top of being Falcon Heavy’s first scheduled night launch, STP-2 has now also marked the massive rocket’s first nighttime static fire. During this critical test, Falcon Heavy briefly ignites all 27 of its three boosters’ Merlin 1Ds and throttles the engines up to full thrust, much like airliners sometimes set their brakes and throttle up before attempting to take off. The difference between Falcon Heavy and passenger aircraft is nevertheless rather significant, given that Falcon Heavy produces ~15x the thrust of an A380 – the world’s most powerful mass-produced passenger aircraft – at liftoff: 22,820 kN (5.1M lbf) to the massive jet’s meager 1,440 kN (0.3M lbf).
Despite all of that thrust, Falcon Heavy is held down during static fire by eight accurately-named hold-down clamps, themselves a part of a massive transport/erector, which is itself anchored directly to Pad 39A’s concrete foundation. In short, Falcon Heavy (and especially Falcon 9) is not going anywhere until those hold-down clamps are explicitly released. Thanks to SpaceX’s avoidance of the solid rocket boosters used by almost every other modern launch vehicle, Falcon 9 and Heavy rockets can abort at any point prior to clamp release, offering a uniquely broad abort capability.
As such, not only does SpaceX’s dedicated pre-launch static fire fully test the rocket’s health, but the same procedure is essentially repeated in the seconds before clamp release during an actual orbital launch attempt. If at any point Falcon 9’s autonomous onboard computer decides that it doesn’t like any of the thousands of channels of telemetry it’s constantly analyzing, it can command an engine shutdown and total launch abort even if all first stage engines have already ignited and reached full thrust. If routine McGregor, TX acceptance testing – also involving a full static fire – is accounted for, every single Falcon 9 booster technically completes three fully-integrated static fires before its inaugural liftoff. Falcon Heavy is slightly different, as each booster is independent test-fired in Texas but the integrated rocket can only perform static fires at Pad 39A.
After those three critical tests, flight-proven Falcon boosters are subjected to the less stringent few-second static fires SpaceX performs at the launch pad 3-7 days before a given launch. With Falcon Heavy Flight 3, the rocket’s center core, upper stage, and payload fairing are all brand new, fresh from either SpaceX’s Hawthorne factory or McGregor acceptance testing. However, both side cores – Block 5 boosters B1052 and B1053 – are flight-proven, having successfully completed their first launches and landings on April 11th, less than 70 days ago.
Set by regular old Falcon 9 boosters, SpaceX’s current record for booster turnaround time (time between two launches) is 71 days (set in June 2018), while the Block 5 upgrade’s record stands at 74 days (set in October 2018). If Falcon Heavy’s STP-2 launch holds strong on June 24th, B1052 and B1053 will simultaneously tie SpaceX’s Block 5 turnaround record. This would be accomplished despite the added pressure from the US Air Force’s decision to use STP-2 as a sort of dress rehearsal for certifying all flight-proven commercial rockets, an honor (and burden) that likely added extra work, oversight, and scrutiny to the process of refurbishing and relaunching B1052 and B1053.
“[T]he US Air Force has decided that STP-2 presents an excellent opportunity to begin the process of certifying flight-proven SpaceX rockets for military launches. The STP-2-related work is more of a preliminary effort for the USAF to actually figure out how to certify flight-proven commercial rockets, but it will still be the first time a dedicated US military mission has flown on a flight-proven launch vehicle. Down the road, the processes set in place thanks – in part – to STP-2 and Falcon Heavy may also apply to aspirational rockets like Blue Origin’s New Glenn and ULA’s “SMART” proposal for Vulcan reuse.”
— Teslarati.com, 06/16/2019
In a last-second surprise, SpaceX updated Falcon Heavy center core B1057’s planned drone ship landing site from a brief 40 km (25 mi) to more than 1240 km (770 mi) off the coast of Florida. SpaceX set its current record for recovery distance less than three months ago during Falcon Heavy’s commercial launch debut, in which Block 5 center core B1055 landed nearly 970 km (600 mi) offshore on drone ship Of Course I Still Love You (OCISLY). If all goes well, B1057 – the second finished Block 5 center core – will absolutely crush its predecessor’s record, implying that the booster will likely be subjected to SpaceX’s most difficult reentry and recovery yet.
For more on what CEO Elon Musk describes as “[SpaceX’s] most difficult launch ever”, check out these previous articles on an unexpected ultra-fast booster reentry and the extraordinary challenge facing Falcon upper stage.
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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 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
