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
Elon Musk just set a condition that could end Falcon 9 as we know it
Elon Musk says SpaceX will finally retire Falcon 9 once Starship flies reliably every week.
Elon Musk gave the clearest timeline yet for retiring Falcon 9, SpaceX’s workhorse rocket.
The comment came in a reply on X, where Musk wrote that “once Starship is flying reliably several times per week, it makes sense to shift super scarce SpaceX engineering and production resources to Starship to get launch rate to several times per day, which means winding down Falcon.” He was responding to physicist Casey Handmer, who noted that NASA is reportedly uneasy about SpaceX phasing out Falcon after building what Handmer called the most successful launcher ever, with the fleet nearing 1,000 total launches.
Now @SciGuySpace reports NASA is in a tizzy because after running the most successful launcher ever for more than a decade and nearing 1000 launches, @SpaceX is planning to retire Falcon in favor of Starship in a few years.
TESLARATI Premium Membership
$19.99 USDSorry, NASA, you’ve had 15 years to burn down the… https://t.co/uCNoMwK0v9
— Casey Handmer (@CJHandmer) August 22, 2026
Falcon 9 is still SpaceX’s busiest vehicle by far. The company is on pace for roughly 140 to 145 Falcon flights this year, following 165 in 2025, president Gwynne Shotwell told Time earlier in 2026. She has already said Falcon flights would “tail off” as Starship comes online, while reports indicate that SpaceX has stopped booking new Falcon 9 launches past 2028 and halted production of some expendable Falcon hardware, according to Bloomberg.
It’s worth noting that Musk’s post is a condition, and not a countdown on when Falcon will retire. Starship has not yet flown weekly, let alone daily. Its most recent flight in July ended with a soft splashdown in the Indian Ocean, a milestone Musk pointed to earlier this month when he said the vehicle’s heat shield problem was effectively solved. SpaceX towed that ship to Christmas Island for inspection, and the next flight, Flight 14, is aimed at putting Starship into orbit for the first time. A tower catch attempt for the upper stage has been pushed back to what Musk has called “a few months” away.
SpaceX and a new Trump order that could rewrite the next decade of launches
The gap between Falcon’s role today and Starship’s promised role tomorrow matters most to NASA. Falcon and its Dragon capsule remain the only way the agency rotates astronauts to and from the International Space Station, and Starship is not certified to carry NASA crews. Musk’s post did not address how that handoff would work if Falcon winds down before a crew-rated Starship variant exists. The timing lines up with Musk’s other recent Starship comments. Two days before the Falcon post, he told a different X user that SpaceX is aiming for more than 30 Starship launches a day by 2030, or roughly 10,000 a year, a figure tied to the Trump administration’s new push for higher national launch cadence. Falcon, which took over a decade to reach its first 100 launches, was never built to approach that kind of volume.
For now, Falcon 9 keeps flying at a near-record pace while Starship works to prove it can do the job Musk has already picked out for it.
Tesla Cybercab is set to launch in Austin, Texas, on September 3, as the company has officially started sending out invitations to a dedicated event it will hold in the city where its headquarters is located.
The Cybercab is Tesla’s dedicated ride-sharing vehicle: it features just two seats and has no steering wheel or pedals. It is aimed at fully autonomous passenger transport, and will operate in the Robotaxi fleet alongside the Tesla Model Y, which has been performing driverless rides for real-world passengers for more than a year.
Thank you so much @Tesla for inviting us to the Cybercab launch in Austin! 🤠 pic.twitter.com/F1rAR8zd5O
— TESLARATI (@Teslarati) August 22, 2026
The launch of the Cybercab marks the next chapter in Tesla’s autonomy story. The company has been developing autonomous transport for years with its Full Self-Driving (Supervised) platform, which is available in any vehicle the company has built with the proper hardware and software capabilities.
Its capabilities vary by hardware and software version, but Tesla says its latest hardware version, known as AI4, can deliver full autonomy. However, future vehicles will operate with even more robust hardware packages, as Tesla will develop AI4.5 and AI5 for even more capability in its vehicles.
Following a report from The Information that surfaced earlier this week, the writing was on the wall that Tesla was set to launch Cybercab in the near term. The report stated Tesla could launch Cybercab as soon as the end of August. Tesla came close and has booked it for September 3.
The big thing with this event being scheduled is not necessarily that Tesla is launching a new vehicle, but instead that it is launching a vehicle that has no steering wheel or pedals and will operate exclusively on a self-driving program that is evidently nearing full autonomy. If the event allows vehicles to take passengers on public roads and drop them off wherever they please within the City of Austin, it will be a drastic advancement in the company’s self-driving story.
People have ridden in Cybercab previously: Tesla had the “We, Robot” event in October 2024, which allowed people to experience fully autonomous rides in a closed circuit at Warner Bros. Studios in Burbank.
🚨 Ride in a Tesla Cybercab with us
— TESLARATI (@Teslarati) May 11, 2025
Additionally, Tesla launched employee rides in Cybercab in July.
It’s a drastic step forward for Tesla, whose CEO, Elon Musk, has promised for years that the company would release a fully autonomous vehicle and platform capable of allowing drivers to relinquish any responsibility behind the wheel.
Elon Musk put a number on where he thinks SpaceX’s Starship program is headed by 2030, replying on X a day after President Trump signed a memo pushing the country toward 1,000 space launches and reentries a year.
The exchange started when Aaron Burnett, co-founder of propulsion startup Mach 33, posted that “1,000 launches/reentries is the goal,” quoting White House science adviser Michael Kratsios on the newly signed National Space Transportation Policy. Burnett noted that the FAA’s own bull-case forecast reached only 385 annual launches by 2030, while his firm’s conservative model already put SpaceX alone near 940. Musk responded, “We’re aiming to reach 30+ Starship launches/day in 2030, which is ~10k annualized. Still tiny numbers compared to airplane flights!”
We’re aiming to reach 30+ Starship launches/day in 2030, which is ~10k annualized.
Still tiny numbers compared to airplane flights!
— Elon Musk (@elonmusk) August 21, 2026
That figure is specific to Starship, the rocket SpaceX is still developing for orbital and lunar missions, not the Falcon 9 fleet that carries most of the company’s current launch volume. Starship has flown twice this year, a slower pace than the four and five flights SpaceX managed in 2024 and 2025. Getting from two flights a year to 30 a day is the scale of jump the new federal policy is meant to clear regulatory room for.
Trump’s memo, signed Thursday, directs agencies to identify new launch and reentry sites on federal land, including a new reentry site within 90 days, and to speed up the permitting and environmental reviews that have long slowed cadence growth. It also sets a goal of returning American astronauts to the moon by 2028 and placing initial lunar base elements by 2030, tying the launch buildout directly to NASA’s Artemis program.
SpaceX has already been pushing the FAA toward higher numbers on its own. The agency approved up to 44 annual Starship launches from Kennedy Space Center in February, on top of a 2024 review that raised the cap at Starbase in Texas to 25 a year. Those approvals cover a fraction of the 10,000 annual flights Musk is now describing, which shows how far current permitting still sits from the administration’s stated target.
The near-term test of all this is more modest. SpaceX cleared a full-duration, six-engine static fire on its next Starship vehicle this week, the last major hardware checkpoint before Flight 14, which is targeting no earlier than August 28 and is expected to attempt the vehicle’s first full orbital mission. Musk said last week that a tower catch of the upper stage is still probably months away, a reminder that the immediate roadmap remains far more incremental than the daily launch numbers he just posted.
Elon Musk just set a condition that could end Falcon 9 as we know it
Tesla will launch Cybercab on September 3
