News
SpaceX’s Starship Raptor Vacuum engine plans laid out by CEO Elon Musk
Elon Musk says that SpaceX Starship engine upgrades are on track to begin static fire tests of a Raptor Vacuum variant as few as a “couple months” from now.
Designed to enable more efficient performance in thin atmosphere or vacuum, Musk admitted that the first version(s) of Raptor Vacuum (RVac) will likely be a compromise between efficiency and speed of development. Nevertheless, the faster SpaceX can prepare Raptor Vacuum for flight, the easier it will be for Starship to begin serious (sub)orbital flight tests.
As it turns out, SpaceX’s first and only official render of Raptor – published in September 2016 – showed the engine’s vacuum-optimized variant. In the years since, CEO Elon Musk has vacillated between keeping the vacuum engines as a central Starship feature and simply replacing them with regular sea level Raptors to expedite the spacecraft’s debut. The 2016 and 2017 vehicles featured a mixture of vacuum and sea-level engines, whereas Musk revealed a vehicle with sea-level engines only in 2018.



Perhaps less than a month after Musk’s September 2018 presentation, the SpaceX CEO made the decision to radically redesign the vehicle – newly christened Starship and Super Heavy – by moving from a carbon composite aerostructure to stainless steel. At first, the seven SL Raptors remained a part of the design, but Musk took to Twitter in 2019 to indicate that SpaceX had changed gears again and had reprioritized Raptor Vacuum development.
This came as a bit of surprise and it should go without saying that there’s a significant chance that Musk/SpaceX will oscillate in the opposite direction once again before Raptor Vacuum is actually ready for flight. This time, though, Musk has sketched out a development schedule and strategy that suggests SpaceX is much more serious this time.
Most notably, Musk claims that the first Raptor Vacuum prototype could be ready for static fire testing just a “couple months” from now, an immensely ambitious schedule for any large liquid rocket engine development program. Nevertheless, Musk did indicate that the “V1.0” Raptor Vacuum design would be significantly compromised and “suboptimal”, an intentional decision to prioritize the engine’s “speed of development”.
Even then, Musk believes that the first variant – featuring a shortened bell nozzle – could still be up to 12% more efficient than sea level Raptors and thus already 70-80% of the way to the physical limit of methane-oxygen rocket efficiency.

On a positive note, shrinking V1.0 Raptor Vacuum’s nozzle a bit from its nominal length will likely mean that SpaceX can static fire fully-integrated engines at its McGregor, TX test facilities, critical for speedy development. If not, the company has experience with alternatives through Merlin Vacuum, which can only be tested on the ground with its lengthy nozzle detached. This method just makes it dramatically harder to optimize a vacuum nozzle design, as full-scale, flight-like testing is nearly impossible if a given vacuum engine can’t be tested on the ground with said nozzle installed.
Vacuum engines need such large and unwieldy nozzles in order to make them as efficient as possible. In a very simplistic sense, a rocket engine nozzle directs the flow of superheated, ultrafast gases in order to squeeze as much momentum transfer as possible out of available propellant. The lower the pressure of the surrounding atmosphere is, the more those gases will expand immediately after leaving the nozzle – giant vacuum nozzles simply try to harness the additional momentum available from that extra expansion. This is why rocket exhausts appear to spread and thin out as launch vehicles reach higher and higher altitudes.

In this sense, the perfect theoretical vacuum nozzle is quite literally infinitely long. The job of vacuum rocket engineers is to find the perfect balance between that impractical theoretical perfection and the limits of real-world materials and dynamics. In theory, SpaceX’s sea-level Raptor engines have already been designed to operate in vacuum conditions, while the engine’s closed-cycle design and regeneratively (i.e. propellant) cooled nozzle should apply well to a vacuum design.
If SpaceX is lucky, there will be few roadblocks in the way of simply lengthening a SL Raptor-style nozzle and calling it a day, in which case it would be impressive but not all that surprising if SpaceX is actually able to begin RVac testing before the end of 2019. Once a rough V1.0 engine is in place, the process of optimizing efficiency can be done slowly and methodically, all while exploiting an unprecedented wealth of data from flight and orbit-tested Raptor Vacuum engines.
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Elon Musk
Tesla reveals various improvements to the Semi in new piece with Jay Leno
Tesla Chief Designer Franz von Holzhausen and Semi Program Director Dan Priestley joined Leno in a 47-minute segment revealing all of the various things it did to make the Semi even better as it heads toward volume production this year.
Tesla has revealed the various improvements it has made to the Semi with its redesign, which was unveiled late last year, on a new episode of Jay Leno’s Garage.
Tesla Chief Designer Franz von Holzhausen and Semi Program Director Dan Priestley joined Leno in a 47-minute segment revealing all of the various things it did to make the Semi even better as it heads toward volume production this year.
Last year, Tesla revealed it had updated the Semi design to fit the bill of its aesthetic, which, on its other vehicles, includes things like lightbars and a sleeker and more aerodynamic design. The changes were not all to appease the eye, but the drivers who will use the Semi on a daily basis to haul goods regionally as the program gets off the ground running.

Weight Reduction
Priestley revealed almost immediately that Tesla was able to cut out about 1,000 pounds of weight from the Semi compared to the previous version.
This does several things, all of which are positive to the mission of a Class 8 truck, which is to haul goods and obtain more efficient travel to cut down on logistics costs.
Initially, this can increase payload capacity, which is often the biggest value driver for fleets that frequently hit gross vehicle weight limits. Tesla’s early Pilot Program members, like PepsiCo. and Frito-Lay, are large-scale companies. They will benefit from a decreased overall weight.
Lighter vehicles also require less energy to accelerate, climb hills, and maintain highway speeds. This new design has that advantage, and as Leno said in his first drive with the Semi as he hauled another unit behind, “I don’t feel like I’m pulling anything.”
Drag Coefficient
Franz said one of the goals of the Semi was to get the drag coefficient down below that of a Bugatti Veyron. This would increase efficiency tremendously, a major need with a large truck like a Semi.
Drag coefficient is extremely valuable when it comes to electric vehicles, because the displacement of air is incredibly important for range ratings.
Franz said aerodynamic efficiency has been improved by 7 percent compared to the last model. He says the coefficient is around 0.4.
New Features and Improvements
Priestley shed some additional light on the Semi and some of the improvements the company has made under the hood.
These include:
- Fully Electric Steering Assist
- Cybertruck actuators are being used for more strength
- Tesla included a 48-volt architecture
- Semi will utilize 4680 battery cells, which are designed to last 1 million miles

These changes come after Tesla rolled out the Semi to various companies for its Pilot Program, which yielded tremendous results. Due to the years it has been working with those companies, it knew what things it had to change and what it had to improve upon before selling the Semi openly.
Fleet Data
The fleet data Tesla has gathered from the Pilot Program has been one of the most widely discussed parts of the Semi program.
Franz and Priestley said that there are currently a few hundred Semi units in the real world, and Tesla has gathered 13.5 million miles. One of those units has traveled over 440,000 miles in the years it has been on the road.
Tesla Semi’s latest adoptee will likely encourage more of the same
Pilot Program members have reported an uptime of 95 percent, and Tesla’s maintenance and Service teams have kept things running:
“80% of breakdowns if you have one, are returned back to the customer in less than 24 hours, and half are back in less than 1 hour.”
Demand
Priestley says demand for the Semi has never been higher, and due to the recent political climate and the impact things have had on gas prices, Tesla has never received more inquiries for the Semi than it has recently.
Many companies will be surprised to hear that the Semi Pilot Program has been an overwhelming success. As Tesla begins to build out the infrastructure for the vehicle, it will only benefit the all-electric Class 8 trucks that keep things moving.
CEO Elon Musk said Tesla plans to start high-volume production this year. The company also plans to start deliveries this year.
News
Tesla launches amazing new feature for shared vehicles
Tesla has quietly introduced one of its most practical software features yet in update 2026.8: real-time visibility of the active driver profile directly in the Tesla mobile app. Available under the Security & Drivers section, this new tool lets owners see exactly who is behind the wheel or who last drove the vehicle.
Tesla is launching an amazing new feature for shared vehicles, giving owners more transparency when they choose to have a Tesla ownership experience with another driver.
This is one of the many advantages of having a Tesla. New features are constantly rolled out through software updates and Over-the-Air fixes, which download directly to the car with an internet connection.
Tesla has quietly introduced one of its most practical software features yet in update 2026.8: real-time visibility of the active driver profile directly in the Tesla mobile app. Available under the Security & Drivers section, this new tool lets owners see exactly who is behind the wheel or who last drove the vehicle.
The feature works seamlessly. While the car is driving, the app displays the name of the currently selected driver profile in real time.
When the vehicle is parked or asleep, it shows the last active profile.
Requiring both the 2026.8 vehicle software and the latest Tesla app, the update brings this capability to every model in the lineup, including legacy Model S and Model X vehicles, which are unfortunately being phased out of the company lineup later this year.
Tesla makes latest move to remove Model S and Model X from its lineup
The feature was first reported on by Not a Tesla App.
Tesla driver profiles have always excelled at personalization, automatically adjusting seat positions, mirrors, steering wheel height, climate settings, navigation recents and favorites, and media preferences.
These profiles link to specific phone keys for automatic activation and support PIN protection for privacy and security. Restricted profiles for teens can also limit speed or features.
This feature shines brightest in single-car households with multiple drivers. Families, couples, and roommates frequently share one Tesla, leading to constant adjustments and questions about settings. Now, a quick app check reveals the current profile, allowing users to anticipate seat configurations or confirm usage without entering the vehicle.
Tesla’s cloud-synced driver profiles to bring custom settings across multiple cars
Parents particularly benefit: they can verify that teens are driving under their assigned (and possibly restricted) profiles, adding a layer of safety oversight and peace of mind. Teslas are already so incredibly safe that many parents dream of putting their kids in one.
Two kids around the same age could now share a Tesla, and this feature would make that effort, which is likely to be a difficult one at times, more seamless.
Beyond convenience, it promotes accountability and reduces everyday friction. No more manual profile switching or arguments over mirror positions. Before approaching the car, anyone can check the app and know exactly what to expect, no more wasted minutes readjusting everything.
In multi-driver setups, it transforms the shared EV into a truly intelligent, user-aware machine that respects individual preferences while keeping the primary owner informed.
Tesla’s commitment to over-the-air updates continues to enhance ownership value years after purchase.
This small but significant addition highlights how software can solve real-world problems in multi-user environments, making Tesla vehicles more family-friendly and practical than ever. For the millions of owners sharing a single car, the 2026.8 update delivers transparency, time savings, enhanced safety, and effortless personalization. It is a great new feature that is rolling out to vehicles now.
Elon Musk
Elon Musk’s TERAFAB project: Everything you need to know
The CEO has hinted heavily for several quarters that it would probably need to produce its own computing power to stay up to speed on the demand it is facing for its projects. It is now taking matters into its own hands.
On Sunday, Elon Musk formally made TERAFAB official—a groundbreaking $20-25 billion joint venture uniting Tesla, SpaceX, and xAI, three of the world’s richest man’s most significant and powerful ventures.
Musk described the project as “the most epic chip building exercise in history by far.”
Elon Musk launches TERAFAB: The $25B Tesla-SpaceXAI chip factory that will rewire the AI industry
The initiative aims to produce over one terawatt of AI compute annually, dwarfing the global industry’s current output of roughly 20 gigawatts per year. Musk framed the effort as “the next step towards becoming a galactic civilization,” positioning it as essential for scaling humanity into a multi-planetary species.
The Need for TERAFAB
Existing chip suppliers such as TSMC, Samsung, and Micron cannot expand quickly enough to meet the explosive demand for AI hardware.
We’re building TERAFAB to close the gap between today’s chip production & the future’s demand – a future among the stars.
Join us → https://t.co/512DIlqNgY pic.twitter.com/ATr0e0pRDJ
— SpaceX (@SpaceX) March 22, 2026
Musk explained the situation clearly:
“We’re very grateful to our existing supply chain… but there’s a maximum rate at which they’re comfortable expanding. We either build the Terafab or we don’t have the chips, and we need the chips, so we build the Terafab.”
The CEO has hinted heavily for several quarters that it would probably need to produce its own computing power to stay up to speed on the demand it is facing for its projects. It is now taking matters into its own hands.
Chip Types and Production Goals
The facility will manufacture two specialized chip families, according to the presentation:
- Edge-inference AI5 and AI6 processors optimized for Tesla’s Optimus humanoid robots and Full Self-Driving systems in vehicles and Robotaxis
- High-power D3 chips hardened for space environments
Musk outlined annual output targets, which are between 100 and 200 gigawatts of terrestrial compute for robotics, supporting Musk’s vision of producing 1-10 billion Optimus units per year, and the majority (80%) of chips dedicated to orbital AI data centers. Overall, TERAFAB aims to produce 100-200 billion custom AI and memory chips each year.
Scale and Strategy
The size of the TERAFAB project will be remarkable, as Musk indicated after the presentation that the entire Gigafactory Texas campus would not be large enough to fit the needs of the project. In fact, Musk said it would be around 100 million square feet in size, the equivalent of 15 Pentagons or three Central Parks.
Yes, the one in New York City.
Construction will begin with an “advanced technology fab” on the Giga Texas campus in Austin, enabling rapid iteration: design a chip, fabricate lithography masks, produce and test wafers, all within days.
However, the full-scale TERAFAB requires thousands of acres and over 10 gigawatts of power, far exceeding what Giga Texas can accommodate. Musk stated:
“We couldn’t possibly fit the Terafab on the GigaTexas campus. It will be far bigger than everything else combined there.”
Multiple large sites are currently under consideration, but this will need a sprawling land mass to get started.
The sheer scale of TERAFAB is going to be insane.
Elon said it wouldn’t be suitable for anywhere on Giga Texas property because it’s too big:“We couldn’t possibly fit the Terafab on the GigaTexas campus. It will be far bigger than everything else combined there.
Several… pic.twitter.com/79GbhNNuf4
— TESLARATI (@Teslarati) March 23, 2026
Key Applications
TERAFAB will be a crucial part of the development of some of Tesla’s most valuable projects, including Optimus and data center development, especially from an orbital standpoint. For that reason, we will break this down into Terrestrial and Orbital applications:
- Terrestrial: Powers autonomous vehicle fleets and billions of Optimus robots performing physical labor
- Orbital: Starship will launch massive AI satellite constellations, starting with 100-kilowatt “Mini” units, and scaling to larger Megawatt models, creating the world’s largest data center in low-Earth orbit.
Space-based advantages include five times greater solar irradiance, efficient vacuum heat rejection, and freedom from terrestrial grid constraints (U.S. electricity generation totals just 0.5 terawatts). Musk emphasized the principle:
“Quantity has a quality all its own.”
We wrote about SpaceX’s recent filing with the FCC for 1 million orbital data center plans.
Strategic Vision
TERAFAB represents vertical integration at an unprecedented scale, combining AI hardware, robotics, and orbital infrastructure.
Musk described the project as “the final missing piece of the puzzle.” With production ramping toward 2027, TERAFAB is set to accelerate an era of abundance, transforming science fiction into reality and positioning Musk’s companies at the forefront of galactic-scale innovation.