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Stoke Space to build SpaceX Raptor engine’s first real competitor

Stoke Space has begun testing parts of an engine similar to SpaceX's famous Raptor.

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3 years ago

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Seattle startup Stoke Space has revealed plans to develop an efficient rocket engine similar to the Raptors that power SpaceX’s Starship.

Formed in October 2019, Stoke Space secured its first significant round of funding – $9.1 million – less than three years ago. At that time, CEO and co-founder Andy Lapsa says that the startup had just five employees, no permanent workspace, and a “barren field” for a test site. Within 18 months, Stoke Space had turned that empty field into an impressive test facility, conducted numerous component tests, and assembled its first full-scale rocket engine – an exotic UFO-like device unlike any seen before.

It also raised another $65 million – enough funding to begin earnestly developing a potentially revolutionary rocket capable of launching more than 1.65 tons (~3600 lb) into orbit for less than half a million dollars. To realize that extremely ambitious goal, Stoke Space has taken the even more ambitious step of attempting to make the first rocket it develops fully reusable. Simultaneously, the company has incorporated several exotic technologies into that rocket, recently culminating in a surprise announcement that it will attempt to develop one of the most difficult types of engines to power that rocket’s booster stage.

Full-flow staged combustion

At the end of an extended interview and tour with YouTuber Tim Dodd (The Everyday Astronaut), CEO Andy Lapsa revealed that Stoke Space has decided to build a full-flow staged combustion (FFSC) engine for the first stage of its reusable rocket. FFSC is the most efficient type of combustion cycle available for a chemical bipropellant rocket engine, but it’s also the most difficult to develop.

A full-flow engine attempts to squeeze every possible ounce of performance out of the propellant it consumes. The most powerful and efficient chemical rocket engines must consume huge volumes of propellant in a short amount of time without destroying the launch vehicle they’re attached to. To create pressure and spin the pumps that are needed to feed that propellant into their main combustion chamber, engines often burn a small amount of propellant in a separate gas generator or preburner. Gas-generator engines vent that exhaust overboard, reducing efficiency but making for a much simpler design. Staged-combustion engines use preburners to create gas that pumps liquid propellant, and that exhaust gas is eventually injected into the main combustion chamber.

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Full-flow staged combustion sets itself apart by having two separate pumps and preburners for oxidizer and fuel. Unlike simpler variants of staged combustion, FFSC engines turn all of their propellant into gas before injecting it into the combustion chamber. That hot gas increases the heat of combustion and the pressure inside the combustion chamber, ensuring that virtually all of the propellant that flows through the engine is combusted and turned into thrust as efficiently as possible. FFSC is exceptionally difficult because of the extra-high temperatures and pressures it requires, as well as the need for an oxygen-rich preburner and pump. In a high-pressure, hot-oxygen environment, virtually anything imaginable – including most metals – will spontaneously combust.

SpaceX’s Raptor engine.
A single-Raptor static fire.
The 33-engine base of Starship’s first stage.
Stoke’s fully-reusable rocket.
The booster appears to have seven FFSC engines.
The upper stage has a single engine with 30 combustion chambers.

Only complex custom-designed alloys can survive those conditions. SpaceX’s Raptor, the only FFSC engine that has ever flown, is especially difficult because it’s meant to be highly reusable. To be successful, Raptor will have to survive those conditions dozens or even hundreds of times in a row with little to no maintenance in between.

The first booster engine Stoke Space ever attempts to build will be a reusable full-flow staged combustion engine powered by liquid methane and liquid oxygen – essentially a smaller version of SpaceX’s Raptor. Stoke’s booster is otherwise familiar and features deployable landing legs like SpaceX’s Falcon boosters. Lapsa says it will likely also have grid fins.

Reusing the upper stage

In some ways, the upper stage of Stoke’s first rocket is even more ambitious. Powered by hydrogen and oxygen propellant, Stoke has designed a conical capsule-like upper stage with an integral fairing. The upper stage’s propulsion is exotic and unique. A large pump will feed propellant to up to 30 combustion chambers distributed around the rim of its heat shield. The exhaust coming from those 30 chambers will expand and partially push against the upper stage’s equally exotic metallic, liquid-cooled heat shield. That expansion against the heat shield improves the efficiency of the upper stage and means that its engine will technically be an aerospike.

The upper stage prepares for reentry.
The upper stage separates from the booster.
A render of the upper stage heat shield.
The upper stage touches down.
Individual Stoke thrusters.
A 15-chamber static fire.
A prototype of the upper stage heat shield and engine.
A prototype of the upper stage tanks. (Everyday Astronaut)

Stoke has already begun testing a full-scale version of the upper stage’s UFO-like rocket engine with 15 combustion chambers. Since testing began in the second half of 2022, Stoke has completed dozens of static fires. Everyday Astronaut’s tour also revealed that the startup has made significant progress fabricating and assembling its first full-scale upper stage prototype – tanks, nosecone, heat shield, engine, and all.

Reminiscent of SpaceX’s Grasshopper and Starhopper campaigns, Stoke plans to conduct hop tests with that prototype if it makes it through qualification testing. On February 7th, Stoke also revealed that it’s begun testing a crucial component of its full-flow booster engine. All told, Stoke Space is making progress at a remarkable pace and continues to tackle the hardest problems. The startup has also avoided widely publicizing any specific deadlines, instead choosing to let hardware and tangible results speak for themselves. Only time will tell if that approach pays off, but Stoke is off to an exceptionally impressive start in an industry full of impressive rocket startups.

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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 owners show off improvements with new Full Self-Driving v14 rollout

Some of the big things that Tesla faced head-on with the development and release of v14 were navigating in parking garages and handling parking after arriving at a destination.

Published

2 hours ago

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October 7, 2025

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Credit: Tesla Europe & Middle East/X

Tesla owners with access to the company’s Full Self-Driving new version, v14, which rolled out on Tuesday morning, are showcasing some of the very impressive improvements that have arrived.

CEO Elon Musk called v14 “sentient” a few weeks ahead of its rollout, claiming the newest iteration of the company’s Full Self-Driving platform would be the most accurate to date.

Tesla FSD (Supervised) V14.1 with Robotaxi-style dropoffs is here

It was obvious this narrative had Tesla owners keeping their expectations high, as there were very evidently things that needed to be improved upon that were present in v13. I wrote about several improvements I was hoping to see, and based on the release notes for v14, Tesla did have these things in the works already.

Some of the big things that Tesla faced head-on with the development and release of v14 were navigating in parking garages and handling parking after arriving at a destination.

Tesla said it was working to increase the capabilities of Summon within parking garages, as many owners believe that is where it would be the most beneficial.

While that does not appear to be part of this initial v14 rollout, it does seem Tesla is focused on improving the suite’s ability to navigate through these garages, including stopping for a ticket to enter the facility, finding a spot, and parking in an appropriate space.

It was evident this was a huge improvement based on one example from an owner who received v14:

If you look closely, you will even see the car shift slightly to the right when it arrives at the ticketing station, making it easier for the driver to hand over their ticket and payment. It then moves back out to the right when leaving to return to the center of the lane. It’s very intuitive.

Additionally, it appears to be more accurate when parking, thanks to improvements that enable owners to select the type of parking upon arrival at a destination.

In the v14.1 release notes, Tesla said that it has added “Arrival Options for you to select where FSD should park: in a Parking Lot, on the Street, in a Driveway, in a Parking Garage, or at the Curbside.”

One owner chose to navigate home and chose a garage to park in. Full Self-Driving performed it without any issues:

These are just two evident improvements so far, and there are likely many more on the way. The changes and fixes will be tracked by anyone with access to FSD v14 in the coming weeks.

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Tesla Optimus steals the show during TRON: ARES premiere

Now that kung-fu Optimus demonstration makes sense.

Published

4 hours ago

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October 7, 2025

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Credit: Tesla Optimus/X

Just a few days ago, Elon Musk shared a video of Tesla Optimus demonstrating some kung fu moves with a human partner. The video was impressive, though some were confused about why the Optimus team was busying itself with what appeared to be a cool but frivolous demonstration. 

With the premiere of TRON: ARES, we now know that Optimus’ kung fu demonstration was part of the robot’s preparations for the red carpet. 

Optimus “starts a fight”

As noted by X Business on its official account on the social media platform, the TRON: ARES red carpet world premiere was a showcase of today’s AI-powered technologies. With this in mind, xAI, X, Walt Disney, and Tesla collaborated to provide attendees with an immersive experience on real-world AI. This included Optimus engaging with attendees, and even distributing theater concessions. 

But one black and red painted Optimus unit definitely stole the show. The humanoid robot, in front of several attendees, attempted to “pick a fight” with Jared Leto, who starts in the movie alongside Greta Lee, Evan Peters, and Jeff Bridges. As could be seen in the video of Optimus, the robot’s moves in the red carpet were similar to the kung fu demonstration that Elon Musk showcased last week. 

TRON: ARES

Monique Pintarelli, Head of Americas at X, shared some insights about the event, which ended up being a collaboration of sorts between several Elon Musk-led companies. 

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“This partnership with Disney lets fans and stars experience the world of TRON like never before – turning the red carpet event into a collision between the real world and AI. By leveraging X’s unparalleled real-time engagement and xAI’s cutting-edge technology alongside Tesla’s Optimus robots, we’re creating shared, immersive experiences that redefine storytelling,” the X executive noted.

TRON: ARES releases on U.S. theaters on October 10, 2025. 

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Tesla FSD (Supervised) V14.1 with Robotaxi-style dropoffs is here

This represents FSD’s most significant update in nearly a year.

Published

10 hours ago

on

October 7, 2025

By

Credit: Sawyer Merritt/X

Tesla has started the rollout of Full Self-Driving (Supervised) V14.1, the advanced driver-assist system’s most significant update in nearly a year. The release introduces vision-based navigation for real-time detour handling and a new “Arrival Options” feature that simulates Robotaxi-style drop-offs.

New Tesla Vision-based features

With Version 14.1, Tesla has integrated navigation and routing directly into its vision-based neural network, enabling the system to respond to scenarios such as blocked roads or closures in real time. The update also enhances emergency vehicle detection, allowing the car to pull over or yield when police, fire, or ambulances are nearby.

Other improvements include refined responses to debris, school buses, and lane cut-ins, as well as smoother handling of unprotected turns and gated entries. The update also adds a Robotaxi-style automatic camera-cleaning system. Tesla also promises improved fault recovery for greater reliability during degraded system operation.

New Speed Profiles and other features

Drivers can now personalize FSD’s behavior more precisely through new Speed Profiles. A new “Sloth” mode has joined the lineup, offering a more conservative lane and speed selection than “Chill.” Preferences for parking and arrival positions are saved per destination, while the system’s reasoning model automatically recommends several options for each route.

Users can start FSD from a single tap, adjust settings from the central visualization, and expect fewer driver “nags,” according to Elon Musk. The CEO noted that Version 14 features a 10x higher parameter count and said it “feels sentient” compared to earlier builds. While it’s still a supervised system, unlike the Austin Robotaxi pilot, FSD 14.1 seems to be a key milestone toward the refinement of Tesla’s autonomous driving efforts.

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FSD (Supervised) V14.1 release notes

Following are the release notes for FSD (Supervised) V14.1:

FSD(Supervised) v14.1 includes:

• Added Arrival Options for you to select where FSD should park: in a Parking Lot, on the Street, in a Driveway, in a Parking Garage, or at the Curbside.

• Added handling to pull over or yield for emergency vehicles (e.g. police cars, fire trucks, ambulances).

• Added navigation and routing into the vision-based neural network for real-time handling of blocked roads and detours.

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• Added additional Speed Profile to further customize driving style preference.

• Improved handling for static and dynamic gates.

• Improved offsetting for road debris (e.g. tires, tree branches, boxes).

• Improve handling of several scenarios including: unprotected turns, lane changes, vehicle cut-ins, and school buses.

Improved FSD’s ability to manage system faults and recover smoothly from degraded operation for enhanced reliability.

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• Added automatic narrow field washing to provide rapid and efficient front camera self-cleaning, and optimize aerodynamics wash at higher vehicle speed.

• Added alerting for residue build-up on interior windshield that may impact front camera visibility. If affected, visit Service for cleaning!

Upcoming Improvements:

• Overall smoothness and sentience

• Parking spot selection and parking quality

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• You can now select an arrival option such as Parking Lot, Street, Driveway, Parking Garage and Curbside for Robotaxi-style drop offs.

• Your preferences for arrival options and preferred parking positions are persisted for each destination.

• Our reasoning model will assess the suitable options for your destination and pick an intuitive default.

Speed Profiles:

FSD (Supervised) will now determine the appropriate speed based on a mix of driver profile, speed limit, and surrounding traffic:

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• Introduced new Speed Profile SLOTH, which comes with lower speeds & more conservative lane selection than CHILL.

• Driver profile now has a stronger impact on behavior. The more assertive the profile, the higher the max speed.

• Right scroll-wheel up/down now adjusts Speed Profile setting rather than your precise max speed offset selection in mph/kph.

UI Improvements:

• Start Self-Driving with a tap of the touchscreen from Park, or any time during your drive.

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• Adjust settings like the Speed Profile and Arrival Options directly from the Autopilot visualization on the center display.

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