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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Tesla has lost its Model Y Program Manager, he announced on LinkedIn, marking the second major departure from the company today.
Emmanuel Lamacchia has been in the role for 4 years and 7 months, responsible for the rollout of the all-electric crossover in several markets.
The Model Y became the best-selling vehicle in the world for two years under Lamacchia’s watch, making this a huge loss for the company. However, it seems the decision was made under Lamacchia’s own initiative.
He confirmed his decision on LinkedIn:
“After 8 incredible years, I’m moving on from Tesla.
What a journey it’s been… from leading NPI for Model 3 and Model Y variants to becoming the Vehicle Program Manager for Model Y, the best-selling car in the world!
Leading the All-New Model Y launch was the highlight: converting all 4 factories across 3 continents in just 2 weeks. Something that had never been done before in the auto industry.
To the teams who made this possible: you should be incredibly proud. This achievement belongs to you: the engineers, designers, buyers, and associates in Fremont, Shanghai, Berlin, and Austin who turned an impossible timeline into reality.
Grateful to the leaders who trusted me with programs that stretched my capabilities and to the cross-functional partners who showed me that great solutions come from collaboration, not hierarchy.
Tesla taught me how to move fast without breaking things and how to scale from prototypes to millions of units.
Excited for what’s next. More to share soon.”
It marks the second major program loss for Tesla today, as it also bid farewell to Cybertruck and Model 3 Program Manager Siddhant Awasthi, who said he left voluntarily in “one of the hardest decisions of his life.”
Lamacchia was at Tesla for just a shade under eight years, and previously worked for Rolls-Royce for roughly the same amount of time.
After the loss of both Lamacchia and Awasthi today, Tesla has lost a handful of key executives in 2025, including:
- David Imai, Director of Design
- David Lau, VP of Software Engineering
- Mark Westfall, Head of Mechanical Engineering
- Prashant Menon, Regional Director in India
- Vineet Mehta, Head of Battery Architecture
- Omead Afshar, VP/Head of Sales and Manufacturing in North America
- Milan Kovac, Head of Optimus Team
- Jenna Ferrua, Director of HR
- Troy Jones, VP of Sales, Service, and Delivery
- Pete Bannon, VP of Hardware Engineering
- Piero Landolfi, Director of Service
News
Tesla prepares to expand Giga Texas with new Optimus production plant
Drone operator Joe Tegtmeyer recognized Tesla construction crews performing ground leveling and clearing efforts at the plant earlier today.
Tesla is preparing to expand Gigafactory Texas once again with a brand new facility that will house the eventual manufacturing efforts for Optimus, its humanoid robot.
It is already building some units on a Pilot line at the Fremont Factory in Northern California, but Tesla is planning to build the vast majority of its Optimus project at Gigafactory Texas.
Tesla Optimus gets its latest job, and it’s not in the company’s factories
It will build one million units per year in Fremont, but CEO Elon Musk said the company would build 10 million units every year in Texas at a new building at Giga Texas.
Musk said:
“I think there could be tens of billions of Optimus robots out there. Um, now obviously it’s very important we pay close attention to safety here. Then a 10 million unit uh per year production line here the I don’t know where we’re going to put the 100 million unit production line. on Mars. Maybe on Mars, I don’t know.”
Evidently, Tesla is ready to begin thinking about the production efforts of Optimus beyond a theoretical standpoint and is starting to prepare for the construction of the manufacturing plant on Giga Texas property.
Drone operator Joe Tegtmeyer recognized Tesla construction crews performing ground leveling and clearing efforts at the plant earlier today:
Giga Texas News!
A brand-new, stand-alone factory is starting construction! This follows the Shareholders meeting & info that a 10-million-per-year @Tesla_Optimus production facility “on the Giga Texas campus” will be built & enter into production in 2027!
Here are some… pic.twitter.com/7ig5DohfOt
— Joe Tegtmeyer 🚀 🤠🛸😎 (@JoeTegtmeyer) November 10, 2025
Production is still slated for 2027, at least at Gigafactory Texas. As previously mentioned, the company is building some units in Fremont for the time being, at least until subsequent versions of the Optimus project advance.
Tesla has done a great job of advancing Optimus forward, but it also has truly grand expectations for the project.
Musk said it could potentially be the biggest product in the history of the planet, as it will revolutionize the way humans perform tasks, probably eliminating monotonous tasks from everyday life.
Tesla revealed its first customer for the all-electric Semi truck after it launches next year. Who it truly is should not be a surprise.
The Semi is going to finally start deliveries to new companies outside of Tesla’s pilot program starting in 2026. The company has been building a dedicated production facility in Reno, Nevada, that has finally taken shape, but Tesla was evidently not finished with the Semi’s development.
Last week at the Annual Shareholder Meeting, Tesla said it had implemented some new designs into the Semi, helping with efficiency, updating its design, and making it a more suitable vehicle for hauling loads, as the changes also helped increase payload.
Tesla has obtained a lengthy list of companies that have committed to implementing the Semi in their own fleets, hoping to bring their logistics lineups up to date with electric powertrains and autonomous technologies.
While it is already operating a pilot program with PepsiCo. and Frito-Lay, Tesla will expand to other businesses, primarily using it internally after its launch.
Head of the Semi program at Tesla, Dan Priestley, said the company would be the first user of the vehicle after its launch next year. It has been using it to a certain extent, but the company has not been able to completely abandon gas haulers.
Instead, it will implement the Semi into its fleet for more sustainable vehicle logistics starting next year:
Tesla will be the first customer as we electrify our supply chain. This includes Texas operations.
— Dan Priestley (@danWpriestley) November 7, 2025
Tesla has already received orders for the Semi from a variety of large companies, including Walmart, Sysco, Anheuser-Busch, UPS, DHL, J.B. Hunt, among others.
Many analysts see the Tesla Semi as a major contributor to future growth and increasing value within the company, especially from a Wall Street perspective. Some firms say the Semi is one of several near and medium-term contributors to the company increasing its market cap.
Cantor Fitzgerald is just one of those firms, as last week it explicitly listed the Semi as a catalyst.
Analyst Andres Sheppard said, “Overall, we remain bullish on TSLA over the medium to long term. We continue to see meaningful future upside from Energy Storage & Deployment, FSD, Robotaxis/Cybercab, Semis, and Optimus Bots.”
Tesla loses Model Y program manager in second blow in single day
Tesla prepares to expand Giga Texas with new Optimus production plant
Tesla reveals its first Semi customer after launch
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