Connect with us

News

SpaceX’s Starship Raptor Vacuum engine plans laid out by CEO Elon Musk

A 2016 render of Raptor Vacuum. Much has changed about the engine's design in the three years since, but SpaceX is still pursuing a vacuum variant. (SpaceX)

Published

on

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.

Known as the Interplanetary Transport System in 2016, the ship featured six vacuum Raptors and 3 SL engines. (SpaceX)
In 2017, Big Falcon Spaceship shrunk and changed to 4 x RVac and 3x x Raptor SL engines. (SpaceX)
In 2018, Musk decided to sidestep vacuum engines entirely, moving to 7 SL Raptors. (SpaceX)

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.

Advertisement
A sea-level Raptor engine is static-fired at SpaceX’s McGregor, TX test facilities. (SpaceX)

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.

A Falcon 9 upper stage’s vacuum nozzle glows white hot during an orbital MVac burn. (SpaceX)

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.

Eric Ralph is Teslarati's senior spaceflight reporter and has been covering the industry in some capacity for almost half a decade, largely spurred in 2016 by a trip to Mexico to watch Elon Musk reveal SpaceX's plans for Mars in person. Aside from spreading interest and excitement about spaceflight far and wide, his primary goal is to cover humanity's ongoing efforts to expand beyond Earth to the Moon, Mars, and elsewhere.

Advertisement
Comments

Elon Musk

Tesla and xAI team up on massive new project

It is the latest move by a Musk company to automate, streamline, and reduce the manual, monotonous, and tedious work currently performed by humans through AI and robotics development. Digital Optimus will be capable of processing and actioning the past five seconds of a real-time computer screen video and keyboard and mouse actions.

Published

on

Credit: Grok

Elon Musk teased a massive new project, to be developed jointly by Tesla and xAI, called “Digital Optimus” or “Macrohard,” the first development under Tesla’s investment agreement with xAI.

Musk announced on X that Digital Optimus will “be capable of emulating the function of entire companies.”

It is the latest move by a Musk company to automate, streamline, and reduce the manual, monotonous, and tedious work currently performed by humans through AI and robotics development. Digital Optimus will be capable of processing and actioning the past five seconds of a real-time computer screen video and keyboard and mouse actions.

Essentially, it will be an AI version of a desk worker in many capacities, including accounting, HR tasks, and others.

Musk said:

“Grok is the master conductor/navigator with deep understanding of the world to direct digital Optimus, which is processing and actioning the past 5 secs of real-time computer screen video and keyboard/mouse actions. Grok is like a much more advanced and sophisticated version of turn-by-turn navigation software. You can think of it as Digital Optimus AI being System 1 (instinctive part of the mind) and Grok being System 2. (thinking part of the mind).”

Its key applications would be used for enterprise automation, simulating entire companies, high-volume repetitive tasks, and potentially, future hybrid use with the Optimus robot, which would handle physical tasks, while Digital Optimus would handle the clerical work.

Tesla announces massive investment into xAI

The creation of a digital AI suite like Digital Optimus would help companies save time and money, as well as become more efficient in their operations through massive scalability. However, there will undoubtedly be concerns from people who are skeptical of a fully-integrated AI workhorse like this one.

From an energy consumption perspective and just a general concern for the human workforce, these types of AI projects are polarizing in nature.

However, Digital Optimus would be a great digital counterpart to Tesla’s physical Optimus robot, as it would be a hyper-efficient addition to any company that is looking for more production for less cost.

Musk maintains that there is no other company on Earth that will be able to do this.

Continue Reading

Elon Musk

Tesla China posts strong February wholesale growth at Gigafactory Shanghai

The update was shared by Tesla observers on social media platform X, citing monthly China Passenger Car Association (CPCA) data.

Published

on

Credit: Grace Tao/Weibo

Tesla China sold 58,599 vehicles wholesale in February, reflecting strong year-over-year growth. The figure includes both domestic deliveries in China and vehicles exported to international markets.

The update was shared by Tesla observers on social media platform X, citing monthly China Passenger Car Association (CPCA) data.

Tesla’s February wholesale result represents a 91% increase year over year, compared with 30,688 vehicles in February 2025. Month over month, the result was down 15.2% from January, when Tesla China recorded 69,129 wholesale units.

The February total reflects combined sales of the Model 3 and Model Y produced at Gigafactory Shanghai. The facility produces the two vehicles for both domestic sales and exports.

Advertisement

Gigafactory Shanghai continues to serve as Tesla’s primary vehicle export hub, supplying vehicles to markets across Asia and Europe. Data compiled by Tesla watchers shows that 18,485 vehicles were sold domestically in China in January 2026, while exports accounted for 50,644 units during the same period.

Tesla has also been extending financing programs in China as it pushes to strengthen domestic demand. The company recently extended its seven-year ultra-low-interest and five-year interest-free financing programs through March 31, marking the second extension of the promotion this year.

The financing initiative was first introduced on January 6 as a strategy aimed at offsetting higher ownership costs ahead of China’s planned 5% NEV purchase tax in 2026. The promotion was originally scheduled to expire at the end of January before being extended to February and then again through the end of the first quarter.

Tesla’s efforts come amid growing competition in China’s EV market. According to data compiled by CNEV Post, Tesla’s 2025 retail sales in China reached 625,698 vehicles, representing a 4.78% year-over-year decline. Part of that decline was linked to the Model Y changeover to its updated variant in early 2025, which temporarily reduced deliveries during the transition period.

Advertisement
Continue Reading

News

Tesla Model Y L spotted on transport trucks in Australia

One of the sightings was reported along Victoria Parade in Melbourne, and it showed multiple Model Y L vehicles on a transport carrier. 

Published

on

Tesla’s upcoming Model Y L has been spotted on transport trucks in Australia. Sightings of the six-seat extended wheelbase Model Y variant have been reported on social media platform X by members of the Australian Tesla community.

One of the sightings was reported along Victoria Parade in Melbourne, and it showed multiple Model Y L vehicles on a transport carrier. 

The sighting follows earlier observations by Tesla enthusiasts in Sydney, where a covered vehicle believed to be a Model Y L was spotted at a Supercharger.

The Sydney sighting drew attention after observers noted that the vehicle’s tare weight appeared to match the ADR approval listing for the Model Y L, suggesting it could indeed be the extended wheelbase variant of the electric SUV.

Advertisement

Tesla has previously confirmed that the Model Y L will launch in Australia and New Zealand in 2026. The confirmation was reported by techAU following a media release from Tesla Australia and New Zealand.

The Model Y L expands the existing Model Y lineup with seating for six passengers. The vehicle features a longer body compared with the standard Model Y in order to accommodate a spacious second and third row.

Tesla has opted for a 2-2-2 seating configuration instead of a traditional seven-seat layout for the Model Y L. The design includes two individual seats in the middle row to provide easier access to the third row and additional passenger space.

Tesla Australia and New Zealand has also stated that the Model Y L will be covered under the company’s updated warranty structure beginning in 2026.

Advertisement

Tesla has not yet announced pricing or official range figures for the Model Y L in Australia.

Continue Reading