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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 owners in Sweden get direct attention from pro-union groups
As part of their efforts, the group has started distributing informational leaflets to Tesla vehicles across Stockholm, urging them to pressure the electric vehicle maker to sign a collective agreement.
Amid Tesla Sweden’s ongoing conflict with trade union IF Metall, a group of pro-union supporters has begun directing their attention to actual Tesla owners.
As part of their efforts, the group has started distributing informational leaflets to Tesla vehicles across Stockholm, urging them to pressure the electric vehicle maker to sign a collective agreement.
Leaflets on parked Tesla vehicles
As noted in a Dagens Arbete (DA) report, participants of the protest place yellow information slips on parked Tesla vehicles across parts of Stockholm. The slips resemble parking notices that contain information related to the unions’ ongoing strike against Tesla Sweden.
Participants involved in the activity said the leaflets were intended to inform consumers rather than target individual owners. The action was carried out in public areas, with leaflets placed on windshields of parked vehicles. When vehicle owners are present, organizers said they provide verbal explanations of the labor dispute.
Tesla has not commented publicly about the matter as of writing.
Recurring demonstrations against Tesla
The leaflet distribution effort follows weekly demonstrations that have taken place outside Tesla’s workshop and office in Upplands Väsby, where protesters typically gather to express support for a collective agreement. Those demonstrations have included informational outreach to customers and workers and, at times, police presence, according to prior reporting.
In a comment, one of the protesters stated that even Tesla owners must be concerned about the unions’ conflict with the electric vehicle maker. “You may think it doesn’t concern you, as you only drive a car. But it does, as we all have a responsibility for the rules in Sweden.
“We are not looking to hunt down individual Tesla owners. Rather, this is a way to spread opinion and increase pressure on Tesla. It should have some impact if several Tesla owners come in and say that you should sign a collective agreement,” one of the protesters stated.
Tesla has landed a massive deal to expand its charging infrastructure for heavy-duty electric trucks — and not just theirs, but all manufacturers.
Tesla entered an agreement with Pilot Travel Centers, the largest operator of travel centers in the United States. Tesla’s Semi Chargers, which are used to charge Class 8 electric trucks, will be responsible for providing energy to various vehicles from a variety of manufacturers.
The first sites are expected to open later this Summer, and will be built at select locations along I-5 and I-10, major routes for commercial vehicles and significant logistics companies. The chargers will be available in California, Georgia, Nevada, New Mexico, and Texas.
Each station will have between four and eight chargers, delivering up to 1.2 megawatts of power at each stall.
The project is the latest in Tesla’s plans to expand Semi Charging availability. The effort is being put forth to create more opportunities for the development of sustainable logistics.
Senior Vice President of Alternative Fuels at Pilot, Shannon Sturgil, said:
“Helping to shape the future of energy is a strategic pillar in meeting the needs of our guests and the North American transportation industry. Heavy-duty charging is yet another extension of our exploration into alternative fuel offerings, and we’re happy to partner with a leader in the space that provides turnkey solutions and deploys them quickly.”
Tesla currently has 46 public Semi Charger sites in progress or planned across the United States, mostly positioned along major trucking routes and industrial areas. Perhaps the biggest bottleneck with owning an EV early on was charging availability, and that is no different with electric Class 8 trucks. They simply need an area to charge.
Tesla is spearheading the effort to expand Semicharging availability, and the latest partnership with Pilot shows the company has allies in the program.
The company plans to build 50,000 units of the Tesla Semi in the coming years, and with early adopters like PepsiCo, DHL, and others already contributing millions of miles of data, fleets are going to need reliable public charging.
🚨 Pilot working with Tesla to install and expand Semi Chargers is a perfect example of two industry leaders working together for the greater good.
As more commerce companies expand into EVs, Semi Charger will be more commonly available for electrified fleets, making efforts… pic.twitter.com/VPLIYyq15b
— TESLARATI (@Teslarati) January 27, 2026
Tesla is partnering with other companies for the development of the Semi program, most notably, a conglomeration with Uber was announced last year.
Tesla lands new partnership with Uber as Semi takes center stage
The ride-sharing platform plans to launch the Dedicated EV Fleet Accelerator Program, which it calls a “first-of-its-kind buyer’s program designed to make electric freight more affordable and accessible by addressing key adoption barriers.”
The Semi is one of several projects that will take Tesla into a completely different realm. Along with Optimus and its growing Energy division, the Semi will expand Tesla to new heights, and its prioritization of charging infrastructure.
Elon Musk
Elon Musk’s Boring Company opens Vegas Loop’s newest station
The Fontainebleau is the latest resort on the Las Vegas Strip to embrace the tunneling startup’s underground transportation system.
Elon Musk’s tunneling startup, The Boring Company, has welcomed its newest Vegas Loop station at the Fontainebleau Las Vegas.
The Fontainebleau is the latest resort on the Las Vegas Strip to embrace the tunneling startup’s underground transportation system.
Fontainebleau Loop station
The new Vegas Loop station is located on level V-1 of the Fontainebleau’s south valet area, as noted in a report from the Las Vegas Review-Journal. According to the resort, guests will be able to travel free of charge to the stations serving the Las Vegas Convention Center, as well as to Loop stations in Encore and Westgate.
The Fontainebleau station connects to the Riviera Station, which is located in the northwest parking lot of the convention center’s West Hall. From there, passengers will be able to access the greater Vegas Loop.
Vegas Loop expansion
In December, The Boring Company began offering Vegas Loop rides to and from Harry Reid International Airport. Those trips include a limited above-ground segment, following approval from the Nevada Transportation Authority to allow surface street travel tied to Loop operations.
Under the approval, airport rides are limited to no more than four miles of surface street travel, and each trip must include a tunnel segment. The Vegas Loop currently includes more than 10 miles of tunnels. From this number, about four miles of tunnels are operational.
The Boring Company President Steve Davis previously told the Review-Journal that the University Center Loop segment, which is currently under construction, is expected to open in the first quarter of 2026. That extension would allow Loop vehicles to travel beneath Paradise Road between the convention center and the airport, with a planned station located just north of Tropicana Avenue.
Tesla owners in Sweden get direct attention from pro-union groups
Tesla lands massive deal to expand charging for heavy-duty electric trucks
