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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)

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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.

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.

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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.

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Nvidia’s board meets on Jensen Huang, and Elon Musk already has an answer

Elon Musk says it would be an honor to hire Jensen Huang amid Nvidia turmoil.

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Elon Musk says he would welcome Jensen Huang at one of his companies if Nvidia’s board decides to push out its longtime chief executive.

On Wednesday evening, the financial account ZeroHedge posted “Elon please hire Jensen” on X. Musk replied roughly two hours later: “That would be an honor.” Neither Huang nor Nvidia had responded publicly as of Wednesday night.

Musk’s reply came as Nvidia’s board met to decide Huang’s future. The Wall Street Journal reported that directors were preparing to oust him following reports of two extramarital relationships. One involves Alice Huang, a Singapore-based businesswoman whom U.S. intelligence officials reportedly believe was working for China’s Ministry of State Security. The New York Times separately reported a relationship with Kimberly Powell, Nvidia’s vice president of health care. Huang acknowledged being unfaithful in a memo to employees on Sunday but gave no details.


Under Nvidia’s bylaws, a majority of its 11 directors can remove the CEO with or without cause. Bloomberg reported that the board has been working with an outside firm on possible replacements and may name an interim chief, with CFO Colette Kress seen as the likely pick. Nvidia shares fell more than 8 percent in extended trading, according to CNBC, and the company is scheduled to report quarterly earnings on November 17.

Musk has more riding on Nvidia’s leadership than most tech executives. In August, he told investors on SpaceX’s first earnings call as a public company that it would build its AI infrastructure exclusively on Nvidia hardware, calling Vera Rubin “the best architecture.” SpaceX is also working with Nvidia on the compute payload for Starmind, its planned orbital AI constellation. In October, SpaceX said it had a binding commitment for a roughly $40 billion lease of Vera Rubin GPUs and related equipment, with the leases expected to begin in the first half of 2027.

The scale of that dependence is already enormous. On its Q3 call, SpaceX said it was bringing roughly 200,000 to 220,000 Nvidia GB300 GPUs online each month and expects 2.5 to 3 GW of nameplate compute by the end of the year. That buildout is now reaching new sites like the proposed $24 billion power plant and supercomputer campus at Starbase.

The relationship between the two executives also goes back nearly a decade. Huang has often told the story of personally delivering Nvidia’s first DGX-1 AI supercomputer to Musk in 2016, when no other customer wanted one. “Nobody wanted to be part of it, except for Elon,” Huang said on the Joe Rogan Experience last December.

Musk did not say what role Huang might fill, and his reply stops short of a formal offer. Huang co-founded Nvidia in 1993 and still owns about 3.6 percent of its stock, so any move to a Musk company would depend on whether, and how, he leaves the chipmaker he has run for more than three decades.

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Starlink Mini 2 arrives with one feature for true off-grid connectivity

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Credit: SpaceX

SpaceX officially launched the Starlink Mini 2 on November 10, delivering the first portable Starlink terminal designed around independent power.

Invitation-only preorders for select U.S. customers are priced at $999 plus tax, a figure that includes a full year of Roam Unlimited service valued at roughly $2,100. A refundable $100 deposit reserves the kit, with the balance due at shipment, expected to begin in mid-December. Broader availability is listed as coming soon.

The headline feature is the quick-swap 71 Wh battery. Clipped to the rear of the dish without tools, it delivers up to 4.5 hours of connectivity on a single charge.

The 490-gram pack includes its own USB-C port and LED indicators, so users can charge a spare separately and swap it in seconds while staying online. Starlink notes that the terminal can continue operating while the battery charges or run directly from a 60 W USB-C source. The retail box includes one battery, a 60 W USB-C charger, and a 3-meter cable.

Beyond power, the Mini 2 is thinner at 23.1 mm (versus 38.5 mm on the original Mini) while measuring 263 × 314 mm. With the battery and kickstand attached it weighs 1.6 kg.

Built-in Wi-Fi 6 expands coverage to up to 1,800 square feet, an IP67 rating protects against dust and water, and a standard 1/4-20 tripod thread plus physical power button round out the design. Field of view remains 110 degrees, and the unit retains support for mobile use.

For travelers, campers, and remote workers, the swappable battery removes the longstanding requirement for an external power bank or vehicle outlet that defined the first Mini. Spare packs sold separately further extend runtime, turning the compact terminal into a more self-contained solution.

While the bundled $999 invitation price sits well above the original Mini’s current $149 starting point, the included year of service and genuine untethered operation mark a clear step forward in portable satellite internet.

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SpaceX’s $24B Starbase supercomputer plan slipped past a key roadblock

SpaceX wants a Starbase tax break for a $24 billion gas plant and supercomputer campus.

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Concept rendering of SpaceX President Gwynne Shotwell overlooks the company’s Hawthorne, California headquarters as an American flag flies over the campus at sunset.

SpaceX is asking its own company town for a tax break on a $24 billion natural gas power plant and supercomputing facility at Starbase, Texas, and the land it picked sits just outside the reach of a data center moratorium that took effect in neighboring Brownsville last week.

A City of Starbase public hearing notice says SpaceX “proposes to construct, own, and operate a gas-fired power plant and super-compute facility” on roughly 444 acres between Boca Chica Boulevard and the Port of Brownsville. The $24 billion figure covers only the initial phases, and the notice leaves room for future expansions. The Starbase City Commission will consider a property tax abatement and a related economic development agreement at a 7 p.m. hearing on December 9. The notice does not disclose the size or length of the abatement, or how much computing capacity the site would hold.

The location has a history. Over the summer, SpaceX asked Brownsville to remove the tract from its city limits and offered $220 million for water and wastewater projects in return. Brownsville approved the move in August, and Starbase later annexed the land. Brownsville’s own 90-day pause on data center applications took effect last week, and had the tract stayed inside the city, the project likely would have needed a different home.

The power side is already in front of state regulators. SpaceX has applied to the Texas Commission on Environmental Quality for air permits covering 35 mobile gas turbines producing roughly 750 megawatts, according to Politico, which also noted that two of the three Starbase commissioners voting on the incentives are SpaceX executives.

Building its own plant lets SpaceX skip the Texas grid. Gov. Greg Abbott paused new data center grid connections in August pending an audit, but a facility that generates its own electricity does not need one. The air permit still has to clear the TCEQ, where Abbott also ordered a halt on data center permits.

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The bigger test arrives in January. Governor-elect Gina Hinojosa, who unseated Abbott last week, has said she will block data center approvals until the legislature passes new protections, and she has already asked state officials to hold off on any sale of Boca Chica State Park to SpaceX until she is sworn in. Tesla and SpaceX shares both fell the day after the election, and Musk’s first reaction on X was “Data centers in space looking pretty appealing right now.”

That line points to Starmind, SpaceX’s orbital compute constellation. Musk has said terrestrial compute will be “peanuts compared to orbital compute” and expects monthly orbital deployments to pass ground deployments around the end of 2028, as Teslarati reported. Until then, SpaceX still needs gigawatts on the ground. It ended the third quarter with 1.7 GW of nameplate compute, is targeting 2.5 to 3 GW by the end of this year and wants at least 10 GW more in 2027. Its existing Colossus sites around Memphis already run on gas turbines and face a lawsuit from residents over emissions.

Local reaction is split. The South Texas Environmental Justice Network has announced a protest, citing air quality, water use and energy bills, while some Brownsville residents told the Tribune they welcome the jobs. SpaceX did not respond to the Tribune’s questions about the project.

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