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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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Tesla launches improved Model 3 in China with V2L, new interior option

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Credit: Tesla

Tesla has launched its newest iteration of the Model 3 in China with a slew of new features, including the highly requested V2L (vehicle-to-load) feature and a new interior option.

The Model 3 now has a 16″ front touchscreen with improved resolution, a black headliner, V2L capabilities, Zen Grey interior in the Premium and Performance trims, as the White option has officially been discontinued, and 19″ Dark Nova Wheels, which are standard on the Model 3 Premium only.

The touchscreen in the U.S. version of the Model 3 is just 15.4″, so the newly upgraded screen is .6″ larger. Additionally, the Black Headliner, now standard on Model Y vehicles in the U.S., is coming to China.

Additionally, Tesla’s decision to end the white interior option has also made its way to the Asian market, as Zen Grey is the lighter color consumers can now go with. It is slightly different from the previously offered White option:

These options are available in China, Australia, and New Zealand as well, as Giga Shanghai serves those markets, bringing its mass-market vehicles to those countries in the South Pacific.

The Model 3 trims are now priced at:

  • Rear-Wheel-Drive – 235,500 yuan (~$35,000)
  • Long Range Rear-Wheel-Drive – 259,500 yuan ($38,700)
  • Long Range All-Wheel-Drive – 285,500 yuan (~$42,600)
  • Performance – 339,500 yuan (~$50,600)

These features have yet to make their way to the U.S., which might upset some buyers, but it is probably a good sign that Tesla will bring these changes to U.S. trims sometime next year. Potentially, these could come even sooner, as they could be used to stimulate demand for the year-end sales push.

Nevertheless, when things start at Giga Shanghai, they usually end up in the U.S. market. Tesla has also already started to install things like the Black Headliner and larger touchscreen in certain U.S.-built vehicles, so these things will be easy to implement across other vehicles in the lineup.

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The Pentagon taps Elon Musk to design the battlefield of the future

Hegseth named Elon Musk to help lead Project Meridian, a Pentagon study of future warfare.

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Elon Musk has a new role in the Trump administration. Defense Secretary Pete Hegseth announced on war.gov Wednesday that Musk will help lead Project Meridian, a new Pentagon study meant to identify the weapons and technologies the U.S. military will need to fight wars decades from now.

Hegseth unveiled the project during his State of the Force address at Marine Corps Base Quantico in Virginia. Musk will direct the effort alongside Anduril founder Palmer Luckey and former House Speaker Newt Gingrich, working under Pentagon Chief Technology Officer Emil Michael. All three men were in attendance, and Hegseth said their first meeting would take place directly after the speech inside a secure compartmented facility, according to The Hill.

Hegseth said the group “will be focused on discovering, developing, and fielding the weapons and systems that our children and our grandchildren will need in their lifetimes, without any creative limitations or restrictions, on any future battlefield, from under the Earth to beyond the Moon.” He added that Meridian is not meant to produce new strategy or policy documents.

SpaceX to become America’s Military data backbone for missiles, drones, and warfighters

A memo released after the announcement gives Michael until January 28, 2027, to deliver findings, a window of 120 days. It names artificial intelligence, autonomy, directed energy, robotics and biotechnology as the fields expected to change how wars are fought. The results will come as a public report with a classified annex. The memo says the study will run through a partner organization it does not name, and it does not mention Musk directly. His role comes from Hegseth’s speech and a Pentagon press release.’

Musk had not commented publicly on the appointment as of Wednesday evening. This will be Musk’s first official advisory role in the administration since he left DOGE last year.

The mandate overlaps heavily with Musk’s companies. SpaceX is one of the Pentagon’s largest contractors, with 2026 defense awards topping $8 billion, much of it tied to launches and a suspected Starshield buildout out of Vandenberg. The Pentagon’s release says Meridian will examine domains “from subterranean depths to the cislunar frontier,” which maps onto The Boring Company’s tunneling and Starship’s lunar plans. Tesla’s work on autonomy and Optimus falls within the fields the memo lists.

Meridian was one of six initiatives Hegseth announced Wednesday. Another is a new Autonomous Warfare Command, which the department wants operating as a four-star combatant command by October 1, 2027.

The news lands a day before SpaceX is scheduled to fly a classified National Reconnaissance Office payload on Falcon Heavy, one of three launches the company has planned for Thursday.

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SpaceX set to launch astronauts and a classified Falcon Heavy mission on the same day

SpaceX plans three launches Thursday, including Crew-13 astronauts and Falcon Heavy’s first classified NRO mission.

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Crew Dragon sits atop Falcon 9 at sunrise on Cape Canaveral's pad 40, less than a day before four astronauts are set to launch to the ISS. (Credit: SpaceX)
Crew Dragon sits atop Falcon 9 at sunrise on Cape Canaveral's pad 40, less than a day before four astronauts are set to launch to the ISS. (Credit: SpaceX)

SpaceX is lining up one of the busiest single days in its history, and the company offered a preview on Wednesday morning with a simple post on X: “Sunrise at pad 40.” The video and photos show Falcon 9 standing at Space Launch Complex 40 at Cape Canaveral, roughly a day before it is scheduled to carry four astronauts to the International Space Station.

That launch is only the first of three SpaceX missions planned for Thursday, October 1, across both coasts.

Crew-13 is targeting liftoff at 11:10 a.m. ET, with a backup opportunity Friday at 10:47 a.m. ET. NASA astronaut Jessica Watkins will command the mission, with NASA’s Luke Delaney as pilot and Canadian Space Agency astronaut Joshua Kutryk and Roscosmos cosmonaut Sergey Teteryatnikov serving as mission specialists. According to NASA, Dragon is set to dock with the forward port of the station’s Harmony module around 8 p.m. ET, less than nine hours after launch. Watkins is the only member of the crew who has flown before, and Kutryk will become the first Canadian to reach orbit through NASA’s Commercial Crew Program.

The Falcon 9 booster is flying for the third time after supporting Crew-12 and a Starlink mission, and it will attempt a landing at Landing Zone 40 beside the pad. That site made its debut in February when the Crew-12 booster touched down there, as Teslarati reported at the time. Crew-13 will relieve the Crew-12 astronauts, who have been aboard the station since the middle of February.

On the West Coast, another Falcon 9 is scheduled to lift off from Vandenberg Space Force Base in a window running from 2:18 to 3:16 p.m. ET, a flight NASASpaceflight lists as a Transporter rideshare mission.

The day is set to close at 11:53 p.m. ET, when Falcon Heavy launches from Launch Complex 39A with NROL-97, the first National Reconnaissance Office payload ever to fly on the rocket. SpaceX rolled the vehicle out to the pad Tuesday night. Its two side boosters, which previously flew GOES-U, ViaSat-3 F3 and NASA’s Roman Space Telescope, will return to Landing Zones 1 and 2, while a new center core will be expended in the Atlantic. The Roman launch took place on August 30, so NROL-97 will come barely a month later as Falcon Heavy’s third flight of 2026 and 14th overall.

NASA taps SpaceX to launch the telescope that could unlock new worlds

If all three Florida boosters land as planned, it would be the first time the Space Coast has seen landings at LZ-40, LZ-1 and LZ-2 on the same day, according to the Orlando Sentinel, which has warned residents in Brevard, Orange and Volusia counties that more than one sonic boom is possible.

The schedule arrives just three days after Starship reached orbit for the first time on Flight 14 from Starbase, Texas, deploying 26 Starlink V3 satellites. If Thursday’s missions stay on time, SpaceX will have flown Starship, Falcon 9 and Falcon Heavy from four different pads in about four days.

Crew-13 is also the start of a longer run for Dragon. NASA recently added Crew-15, Crew-16 and Crew-17 to SpaceX’s contract in a $946 million modification, keeping Dragon as the agency’s only operational ride to the station while Boeing’s Starliner remains grounded.

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