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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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SpaceX just cleared a key FCC hurdle in its fight with Verizon and AT&T
The FCC accepted SpaceX’s bid for Grain’s 800 MHz spectrum, opening review for Starlink Mobile.
The Federal Communications Commission has formally opened its review of SpaceX’s plan to buy a nationwide block of 800 MHz spectrum from Grain Management, moving Starlink Mobile one step closer to operating as a full U.S. wireless carrier.
In a public notice issued Tuesday, the FCC’s Wireless Telecommunications Bureau said it accepted for filing the applications to transfer control of two Grain license companies, Prism License Co. 1 and Prism License Co. 2, to Starlink Spectrum Holdings, a wholly owned SpaceX subsidiary. The deal covers 546 paired licenses across 3,224 counties, reaching roughly 100% of the U.S. population in all 50 states, Washington, D.C., Puerto Rico and the U.S. Virgin Islands. The proceeding sits under WT Docket No. 26-313.
Acceptance is not approval. It means the applications cleared an initial review and the public comment window is now open. Comments and petitions to deny are due December 1, and oppositions are due December 8. The bureau also said the conditions attached to Grain’s July purchase of the licenses from T-Mobile, which require rapid buildout for terrestrial and direct to device service, would carry over to SpaceX if the transfer is approved.
SpaceX announced the agreement on October 8, saying the new airwaves would let Starlink Mobile’s signal reach phones inside buildings, something its 2 GHz spectrum from EchoStar cannot do as well. The portfolio includes up to 14 MHz of paired spectrum in the 817 to 824 MHz and 862 to 869 MHz bands, which most existing phones already support. Elon Musk called it “the last critical piece of the spectrum puzzle needed for SpaceX to provide complete phone coverage in America.”
According to the filing, SpaceX would hold up to 89 MHz of total spectrum in any given market after the deal closes, including up to 14 MHz below 1 GHz. That is far under the 385 MHz threshold the FCC uses to flag a transaction for closer competitive scrutiny, and well short of the roughly 300 MHz each of AT&T, Verizon and T-Mobile holds.
Tuesday’s notice does not decide how SpaceX can use the spectrum from orbit. A separate application SpaceX filed on October 27 seeking authority to provide supplemental coverage from space on the same frequencies, along with related waiver requests, is still pending before the commission.
The ground network is already taking shape. Last week, SpaceX picked Qualcomm to supply radios, baseband units and software for a nationwide 5G build, with deployment across tens of thousands of U.S. cell sites starting in 2027. The FCC also voted on October 29 to advance a proposal opening another 482 MHz to direct to device service, though AT&T, Verizon and T-Mobile hacritive pushed to strip nearly 300 MHz from it. SpaceX President Gwynne Shotwell has said service on SpaceX’s own airwaves is targeted for early 2028.
A Tesla upfitter has offered to take over Cybertruck lines from the company in a last-ditch effort to save the all-electric pickup from being completely canceled in the middle of 2027.
Unplugged Performance, the Hawthorne, California-based Tesla aftermarket specialist, has publicly offered to take over Cybertruck production from Tesla, funding the effort “through a consortium of investors.”
An open offer to Tesla: We fully support putting Cybercab first, and we’d be glad to take the Cybertruck line off your hands.
We’d fund it with a consortium of investors and run it at no cost to Tesla’s floor space, headcount, or focus. All of that goes to Cybercab. Cybercab gets first call on battery cells too. We’ll wait our turn.
Tesla gains incremental profit: a license fee, plus FSD and Robotaxi network revenues on every vehicle built.
We’d build the Cybertruck, a three-row CyberSUV, and an unmanned CyberCargo hauler. More autonomous miles, across every surface of this planet and beyond.
Worth a conversation?— UP (@UnpluggedTesla) November 10, 2026
The proposal comes as Tesla prioritizes its Cybercab Robotaxi program and prepares to wind down Cybertruck assembly at Gigafactory Texas around mid-2027.
Founded in 2013 by Ben Schaffer and located adjacent to Tesla’s Design Studio and SpaceX, Unplugged Performance has become a leading provider of premium upgrades for Tesla vehicles, including extensive Cybertruck packages under its UP INVINCIBLE line.
Through its UP.FIT division, the company has also developed purpose-built police and fleet versions of the Cybertruck, including deliveries to agencies such as the Las Vegas Metropolitan Police Department.
In an X post on Tuesday, Unplugged said:
“An open offer to Tesla: We fully support putting Cybercab first, and we’d be glad to take the Cybertruck line off your hands. We’d fund it with a consortium of investors and run it at no cost to Tesla’s floor space, headcount, or focus. All of that goes to Cybercab. Cybercab gets first call on battery cells too. We’ll wait our turn. Tesla gains incremental profit: a license fee, plus FSD and Robotaxi network revenues on every vehicle built. We’d build the Cybertruck, a three-row CyberSUV, and an unmanned CyberCargo hauler. More autonomous miles, across every surface of this planet and beyond. Worth a conversation?”
The arrangement would free Tesla resources and manufacturing capacity for Cybercab while allowing continued production of the stainless-steel pickup and expanded variants. Unplugged Performance indicated it would wait for battery cells after Cybercab needs are met and would generate ongoing revenue for Tesla through licensing and software/network services on the vehicles it produces.
Following strong initial interest, Unplugged Performance posted a follow-up inviting potential investors and strategic partners to email cyber@unpluggedperformance.com. The company clarified that the outreach is solely to gauge interest and does not constitute an offer to sell securities or acceptance of funds at this stage.
The proposal arrives shortly after Elon Musk indicated that Cybertruck production in Texas would be phased out by roughly the middle of 2027 to expand Cybercab output.
Whether Tesla engages with the offer remains to be seen, but the public overture highlights both the aftermarket specialist’s deep experience with the Cybertruck platform and the growing focus on autonomy within Tesla’s manufacturing plans.
Elon Musk said the Tesla Cybercab will perform “a majority of all passenger miles” where it is allowed to operate and that point is “obvious to anyone with eyes and a brain.”
Musk used the point to double down on the company’s decision to ax the cult-favorite Cybertruck, as its production space will be removed and transitioned into additional Cybercab lines. The move has catalyzed a polarizing conversation on whether its right or wrong.
Whatever side you are on — it’s happening.
Dodge ended the Viper.
Audi retired the R8.
Mitsubishi said goodbye to the Lancer Evo.
Ford bid farewell to the Bronco (at one point).
Chevrolet sunset the Camaro.Tesla is ending the Cybertruck. I’m pissed. I’m upset.
Fans of those five automakers mentioned did the same thing. It happens. It sucks. I don’t like it.
But I still love Tesla. I love my Model Y. I hoped to be in a Cybertruck in a little under two years.
I won’t be. But I still won’t put my family in anything else. Too safe. Too advanced. Too much better than everything else.
— TESLARATI (@Teslarati) November 10, 2026
Regardless, Musk seems to be getting to the point that he is done talking about the choice. At some point, you have to think that this was truly a difficult decision for him and the company as well, and this is not something he took lightly. In fact, he’s probably a little bit disappointed with it, too.
But the point remains that the Cybertruck is gone. Musk’s focus is purely on developing an autonomous platform that the world will utilize for transportation, and he’s telling you that anyone “with eyes and a brain” can see it:
@PalmerLuckey @carlhancock Cybercab will do a majority of all passenger miles in any jurisdiction where it is not prohibited by law.
Obvious to anyone with eyes and a brain.
— Elon Musk (@elonmusk) November 10, 2026
Tesla is betting that all of its passengers in the future will be okay with not owning their own personal cars and will be fine with ride-hailing for the rest of their lives. Every dinner, every errand, every trip to the airport and transportation thereafter, will all be operated by ride-sharing, and in Tesla’s perfect world, it will happen in a Cybercab.
As of now, Cybercab is only active in Austin, but it has been spotted all over the country with a driver behind the wheel in those prototypes. In Austin, the car has no steering wheel or pedals for people to control the vehicle.
The Cybertruck dilemma is one that has truly come across the entire Tesla community and while it seems to be a great idea to keep it because people love it, the business side of things is steering Musk and Tesla in another direction.
SpaceX just cleared a key FCC hurdle in its fight with Verizon and AT&T
Tesla upfitter offers to keep Cybertruck alive
