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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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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.

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.

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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.

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.

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 Cybercab fleet doubles to well over 100 units

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(Credit: Teslarati)

Tesla quietly doubled the size of its Cybercab fleet within the Robotaxi program in Austin, Texas, over the weekend to well over 100 units.

The move not only establishes more of the steering-wheel-less and pedal-less vehicles within the ride-sharing fleet Tesla has been operating for a year, but it also solidifies a more robust Robotaxi fleet as a whole.

Riders started receiving notifications from the Robotaxi app that stated: “Cybercab fleet has doubled: more rides available.”

Tesla first launched rides in the Cybercab in early September, although the Robotaxi fleet has been active for over a year, as rides began last Summer. Cybercab is truly Tesla’s most crucial vehicle release yet, as it is the first car any company has built that is geared toward full-fledged and end-to-end autonomy, never needing human intervention for anything.

Only available in Austin at the current time, Cybercab has two seats and has been spotted testing around various U.S. states and regions; Tesla plans to deploy the Cybercab in various U.S. cities in the coming months as a best-case scenario.

Tesla Cybercab gets initial tie-in to localized, in-house cathode plant

The availability of the Cybercab has doubled from just 58 units last Monday to 125 the following Friday. Marking a substantial increase in Cybercab availability, the additional ride-sharing units are more than welcome, as wait times for Cybercabs, especially, were quite high.

The dramatic increase is a sign that demand for Robotaxi is growing and Tesla is feeling more confident that its driverless ride-hailing suite, especially its Full Self-Driving software, is able to handle any traffic situation without explicit direction or supervision from a human being.

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Tesla has a ‘no human contact’ approach for Semi production

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Tesla is advancing a fully automated pipeline for the 4680 battery cells used in its all-electric Semi, spanning production from Giga Texas through shipment and direct consumption on the line at the new dedicated Semi Factory in Sparks, Nevada.

The approach was outlined by Tesla at its September 24 Semi Handover event, which launched high-volume production at its new 1.8-million-square-foot plant in Nevada, which sits adjacent to Gigafactory Nevada and is designed for an annual production rate of 50,000 trucks per year.

After years of pilot builds and what was a four-year-long redesign of the truck, Tesla moved the Semi from 2170 batteries to its in-house 4680 cells, which are made in Austin. The change cuts battery mass and total energy while holding range, a key step in making volume production a realistic possibility.

Cells will leave Giga Texas in trailers, and at the Nevada Semi plant, Tesla intends for a dedicated line to unload those trailers automatically, station the cells, and feed them straight into pack and vehicle assembly.

Both Lars Moravy, Tesla’s VP of Vehicle Engineering, and Dan Priestley, the Head of Tesla’s Semi program, described the goal as a “zero human touch point” from the moment the trailer arrives in Texas until a finished Semi drives off the production line in Nevada.

The unloading system that Moravy and Priestley described is just one piece of a much broader automation push. The plant uses what Tesla calls the highest-capacity electric monorail conveyance in vehicle manufacturing, carrying frames-in-white simultaneously. Powder-coating replaces conventional paint, and many processes that would normally require operators have been designed out.

Tesla has repeatedly said that “the best part is no part,” and the cell-handling plan extends that philosophy from the cell factory floor in Texas all the way to final assembly in Nevada.

If executed as described, the closed-loop flow would reduce labor, handling damage, and inventory buffers while tightening quality control on a component that represents a large share of the truck’s cost and weight. It also shortens the physical and organizational distance between two factories separated by more than 1,200 miles. The Semi itself now shares a bar-wound stator and other components with the Cybertruck, further linking Tesla’s passenger and commercial production systems.

High-volume output is expected to ramp gradually after the first trucks left the new line in April 2026. Early customers include PepsiCo, DHL, and U.S. Foods. Whether the automated trailer-to-line process reaches the promised zero-touch standard will be visible in the coming months as production scales. For Tesla, the Semi factory is another test of how far it can push “the machine that builds the machine” across sites.

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Elon Musk’s AI Grok Bot can now handle banking while your Tesla FSD handles the road

Elon Musk says Grok Bot can manage your finances through linked bank and investment accounts.

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Concept of SuperGrok Bot handling banking in a Tesla via Grok
Concept of SuperGrok Bot handling banking in a Tesla via Grok

Grok Bot now wants access to your wallet, with SpaceXAI rolling out a new Finance integration for its agent platform that lets users link bank, credit card and investment accounts thereby letting their Bots help manage spending, investments and more. Elon Musk amplified the announcement on X with a short endorsement, “Grok Bot can manage your finances.”

The feature builds on two earlier steps. In early September, Grok gained the ability to answer questions about spending, savings, investments and cash flow using accounts connected through Plaid, starting with users in the U.S. Before that, on August 28, SpaceXAI let Grok Bot buy things online through Link, with users approving every spend request and the Bot receiving a single use card for each payment.

Musk has already shown how far he wants users to push it. In late August, when Tesla investor account Teslaconomics said he was weighing whether to give Grok Bot access to his bank accounts, Musk replied, “Try it out. If Grok Bot messes up, we will make you whole.” That promise goes beyond SpaceXAI’s consumer terms, which make users responsible for what their agents do and generally cap the company’s liability at the greater of fees paid or $100. SpaceXAI’s own documentation recommends requiring approval for purchases and financial transfers.

For Tesla owners, the update lands five days after Tesla brought Grok Bot into its vehicles, letting drivers hand off errands by voice while FSD (Supervised) handles the road. Bot access inside the car is currently limited to SuperGrok Heavy subscribers, though Connectors are open to anyone signed into Grok. With Finance linked, a driver could ask for a spending summary or a check on upcoming bills during the commute.

Grok’s role in the car has grown quickly since Tesla’s Summer Update let it control cabin features by voice. We have been using Grok Bot in our own Tesla for several weeks, and here’s how our latest test went.

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