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.
Check out Teslarati’s Marketplace! We offer Tesla accessories, including for the Tesla Cybertruck and Tesla Model 3.
Elon Musk
Tesla’s next-gen Optimus prototype with Grok revealed
The video shows a new Optimus prototype answering questions and taking some very robotic steps, evidently revealing that the next-generation version is in its early stages of development.
Tesla’s next-generation Optimus robot with AI assistant Grok has been revealed in a new video shared on X.
Tesla CEO Elon Musk was with Salesforce CEO Marc Benioff last night, and it appears the frontman gave Benioff an exclusive look at some upcoming technology.
Tesla talks Semi ramp, Optimus, Robotaxi rollout, FSD with Wall Street firm
The video shows a new Optimus prototype answering questions and taking some very robotic steps, evidently revealing that the next-generation version is in its early stages of development. It features Grok for some additional utility, as it answered questions Benioff asked in the short video.
Here’s what was uploaded to X:
Crazy look at Tesla Optimus from Salesforce CEO Marc Benioff, who was hanging out with Elon Musk yesterday!
Love this gold color on you @Tesla_Optimus https://t.co/NGgDqVVf1g pic.twitter.com/q8286aBNKy
— TESLARATI (@Teslarati) September 3, 2025
It appears that there are several big changes to this next-generation version of Optimus, some of which have been discussed by Musk and Tesla in the past.
The first is purely cosmetic, but the gold color that Optimus is wearing in this is a new and fresh look that we have not seen before.
Perhaps the most interesting change that is evident here is the hands, which are much more detailed than past versions of Optimus:
However, we’re not too sure that these are what will be released with the next-gen Optimus, because they don’t appear to be functional, and they are more reminiscent of mannequin hands than anything.
The hands on Optimus have been a significant part of the program, as they are among the most crucial pieces of equipment on a robot. It needs to be able to perform both delicate and more imposing tasks. Tesla has aimed for Optimus to be able to thread needles or play the piano.
It was one of the most discussed improvements the company mentioned in past comments regarding how it planned to improve from Gen 2 to this next version.
Musk mentioned regarding Optimus:
“Next-generation Optimus hand, which we have in prototype form, has actuators that have moved to the forearm, just like humans, and they operate the fingers through cables, just like human hands.”
Within Optimus lies a significant opportunity for Tesla to gain considerable strength in terms of market share and valuation.
If Tesla can efficiently develop and deploy the humanoid robot over the next several years, the company stands to gain, as companies will utilize it for tasks that require tedious labor.
Musk recently said Optimus will be a major contributor to Tesla’s valuation moving forward. He believes it will make up roughly 80 percent of the company’s value.
Elon Musk
Tesla CEO Elon Musk to provide more details for Master Plan Part IV
Musk stated that he would be adding specifics to the plan in a later update.
Tesla CEO Elon Musk will be adding more specifics to the recently-released Master Plan Part IV. Musk shared the update on social media platform X amidst conversations about the general nature of the Master Plan Part IV.
In a conversation on X, Musk responded to a post from Tesla retail shareholder and bull Dave Lee, who observed that the currently released Master Plan Part IV could really just be the introduction to the real plan due to its absence of specifics.
Elon Musk responded, stating that he would be adding specifics to the plan in a later update. “Fair enough. Will add more specifics,” Musk wrote in his post.
Tesla has been following Elon Musk’s Master Plans for decades. The first Master Plan, released in 2006, outlined the company’s path from the original Tesla Roadster to the Model 3, as well as the first steps for Tesla Energy. Master Plan Part Deux, released in 2016, covered the ramp of Tesla Energy, the expansion of Tesla’s vehicle lineup, and the rollout of a Robotaxi service.
Master Plan Part 3 was more ambitious as it was generally an in-depth proposal for achieving a global sustainable entry economy by transitioning to electricity-powered vehicles, homes, and industry, which will, in turn, be powered by renewable energy sources like solar and wind. Master Plan Part 3 also included a five-step plan to accomplish this, allowing the world to transition to a fully electrified future.
Master Plan Part IV, which was released a few days ago, focused on automation and artificial intelligence to achieve sustainable abundance. But while the first two Master Plans were very clear and specific and Master Plan Part 3 was very in-depth, Master Plan Part IV was quite general and vague in comparison. It was easy to tell that Optimus would play a big role in the pursuit of sustainable abundance, but apart from that, there were no specifics as to how Tesla intended to achieve its goals.
Fortunately, these specifics would be discussed by Musk in a later update to the plan.
News
Tesla just had its best wholesale month this year in China
Tesla China’s wholesale figures include both vehicles that are sold domestically and exported abroad.
Tesla China just had its best wholesale month this 2025 so far. In August, the electric vehicle maker sold 83,192 vehicles wholesale, a 22.55% increase compared to July 2025’s 67,886 units.
Tesla China’s wholesale figures are still down year-over-year, but the company’s momentum seems notable, especially with the arrival of the Model Y L.
August 2025 figures
As noted in a CNEV Post report, August 2025’s 83,192 wholesale figures are 4.04% less than the 86,697 units that were sold in the same period last year. It is, however, a 22.55% improvement from the previous month. From January to August, Tesla China sold 515,552 units wholesale, a 12.24% year-over-year decrease.
It should be noted that Tesla China’s wholesale figures include both vehicles that are sold domestically and exported abroad. With this in mind, August’s results bode well for Tesla China, as it suggests that Gigafactory Shanghai is now hitting its pace with both its domestic deliveries and its exports. Giga Shanghai serves as Tesla’s primary vehicle export hub.
Model Y L factor
Tesla had a challenging first quarter this year, thanks in part to the changeover to the Model Y across the Fremont factory, Giga Texas, Giga Shanghai, and Giga Berlin-Brandenburg. This changeover resulted in low sales in the first quarter. Political controversies surrounding Elon Musk and violence against Tesla stores and vehicles in the first and second quarters in the United States and Europe did not help much either.
This Q3, however, Tesla seems to be hitting its stride, especially in China. The launch of the new Model Y L has allowed Tesla to compete in the six-seat, large SUV segment, a market that was previously closed to the standard Model Y. Reports have suggested that Tesla China has been seeing a lot of demand for the Model Y L, which should help the company achieve higher sales this quarter and the remaining months of the year.
Tesla’s next-gen Optimus prototype with Grok revealed
Tesla CEO Elon Musk to provide more details for Master Plan Part IV
Tesla just had its best wholesale month this year in China
-
News4 days agoTesla is overhauling its Full Self-Driving subscription for easier access
-
Elon Musk5 days agoElon Musk shares unbelievable Starship Flight 10 landing feat
-
Elon Musk6 days agoElon Musk reveals when SpaceX will perform first-ever Starship catch
-
Elon Musk1 week agoSpaceX Starship Flight 10 was so successful, it’s breaking the anti-Musk narrative
-
News2 days agoTesla appears to be mulling a Cyber SUV design
-
News5 days agoTesla expands crazy new lease deal for insane savings on used inventory
-
News5 days agoTesla talks Semi ramp, Optimus, Robotaxi rollout, FSD with Wall Street firm
-
News6 days agoTesla launches Full Self-Driving in a new region