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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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SpaceX’s Starfall just went from secret to storefront

SpaceX now pitches Starfall missions with 1,000 kg payloads, weeks of microgravity, and Starlink connectivity.

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An artist’s illustration of a SpaceX Starfall capsule reentering Earth’s atmosphere. (Image: SpaceX)

SpaceX has put up a dedicated commercial page for Starfall, its disk shaped reentry capsule, laying out for the first time what customers actually get when they book a flight. The page, live at spacex.com/starfall, pitches “affordable, routine access to microgravity” and invites companies to get in touch about flying manufacturing, research or testing payloads.

The specs are short and specific. Each Starfall mission carries up to 1,000 kg of payload, supplies 1 kW of power and connects through an Ethernet interface. Mission length is tailored to the customer, and the payload stays online the entire time through Starlink, which means researchers can pull data from an experiment while it is still in orbit instead of waiting for splashdown.

SpaceX is launching a secret spacecraft that could change how things are made in space

SpaceX is aiming the service at three markets. Biomedical customers are told they can grow stem cell organoids, replacement tissue and layered biomaterials. Pharmaceutical companies are pitched on protein and small molecule drug crystals, which form smaller and more uniform shapes without gravity driven convection. Materials science rounds out the list, with semiconductors and other next generation materials grown in vacuum and microgravity.

The page also makes clear which rocket SpaceX is counting on. “By launching on Starship, Starfall brings a reliable and scalable cadence previously unavailable to the market,” the company wrote, contrasting weeks of continuous microgravity with the seconds offered by drop towers and parabolic flights. No price or first operational flight date is listed.

The commercial push is a sharp turn from how Starfall started. SpaceX said almost nothing about the capsule ahead of its first flight in June, and nearly everything known came from FAA and FCC filings describing a disk about 10.2 feet wide and 2.5 feet tall that can return 2,200 pounds of cargo. By its second flight on the Bandwagon-5 rideshare in October, Starfall was listed by name on the mission page, though SpaceX still did not say what it carried.

Customers appear to be lining up. SpaceX said in its third quarter results that it signed three commercial Starfall missions during the quarter. On the earnings call, President Gwynne Shotwell described the capsule as providing “routine relatively low cost access to microgravity environments for scientific research, including improving our understanding of diseases like cancer and diabetes,” and said the three new missions would fly on Starship.

The branding effort extends past the website. SpaceX added a Starfall T-shirt to its online store on Monday as part of a batch of new merchandise, giving the program a place next to Starship, Starlink and Starshield in the company’s lineup.

The move also puts SpaceX in more direct competition with companies it launches. Varda Space Industries, which has built much of the in-space manufacturing market so far, flew its W-Series 7 capsule on the same Bandwagon-5 mission as Starfall in October. Varda’s capsules are roughly three times smaller than Starfall, and SpaceX controls the ride to orbit for both.

Starfall’s near term cadence depends on Starship. SpaceX is preparing for Flight 15 after completing static fires of Ship 42 and its Super Heavy booster in late October, and is aiming to catch both stages with the launch tower on that flight.

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Grok Bot users hit with weekly limits early, Elon Musk explains what happened

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Credit: Grok Bot

Elon Musk said weeks ago during SpaceX’s third-quarter earnings call that the company’s Grok Bot, its autonomous AI Agent platform, was showing “the fastest growth of a product” that he’d ever seen in his life.

Now, SpaceXSI is scaling back Grok Bot users’ weekly limits, much to the surprise of those who have relied on it to take away monotonous tasks in their lives.

Elon Musk’s terse November 1 reply on X captured a sharp tension in the early days of agentic AI. Responding to a user who asked for a Grok Bot usage reset after hitting 100 percent with four days still left on the weekly cycle, Musk wrote: “The cost of serving Grok Bot was unsustainably high relative to revenue.”

The post arrived amid a wave of similar complaints from paying subscribers whose meters had jumped unexpectedly toward or to the limit, sometimes overnight and with little corresponding activity. It also stood in clear contrast to statements Musk had made only days and weeks earlier.

On the SpaceX third-quarter earnings call in mid-to-late October, Musk had described Grok Bot in almost the opposite terms. He called it “the fastest growth of a product that I’ve ever seen in my life” and said he had “never seen anything grow this fast.”

Company figures put paid weekly users at roughly 800,000 earlier in the month, more than doubling over the prior period. Daily active users had climbed from under 100,000 in early September to over 600,000 by late October.

Musk emphasized that the product has no free tier and that users appear to be getting real value beyond what they pay. In other remarks, he noted that usage per user was rising rather than declining, the opposite of the usual decay pattern for new software.

Grok Bot, launched around August, functions as an always-available agent with its own persistent cloud computer; it can schedule, research, shop, browse, and execute multi-step workflows even after the user steps away. Access is bundled into X subscription tiers (roughly $30, $100, and $200 per month) and certain Cursor plans, drawing from shared weekly usage pools whose exact sizes have not been publicly detailed.

The economics of that model are what Musk’s November 1 post put in the spotlight. Agentic systems burn far more compute than ordinary chatbot exchanges. Each task can trigger repeated model calls, tool use, web actions, and sustained background work.

When growth is as rapid as Musk celebrated, the absolute compute bill scales quickly even if average revenue per user stays fixed under flat monthly subscriptions. Industry observers noted the opportunity cost as well: the same GPUs can be rented to other AI labs at higher rates.

A simple back-of-the-envelope comparison circulating after the post illustrated the gap: if every reported daily user paid the top tier, annualized subscription revenue would still be modest relative to the scale of compute infrastructure SpaceX is building and leasing to companies like Anthropic.

Some users also reported possible dashboard anomalies around the same period, though Musk’s framing treated the underlying cost-revenue imbalance as the core issue rather than a pure metering glitch.

The juxtaposition is the core of this exchange. Within roughly two weeks of publicly framing Grok Bot as an unprecedented success with strong unit economics and no free tier, Musk acknowledged that serving the same product had become unsustainable relative to the revenue it generates.

For the broader industry, the episode underscores a structural challenge of the agent era: demand is real and growing faster than many expected, yet the cost of fulfilling that demand through always-on, multi-step agents can outrun subscription pricing before companies can adjust limits, introduce metered billing, or raise prices.

Musk’s reply did not promise an immediate reset or higher allowances; it simply stated the constraint. In doing so, it supplied a rare, explicit public data point on the unit economics of a high-profile AI agent just as adoption numbers were still being celebrated as the fastest in Musk’s experience.

The tension between rapid, paid growth and the compute required to deliver it is now on the record.

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Tesla owners who tap Emergency Drive Away for fun are in for a surprise

Tapping Activate on Tesla’s Emergency Drive Away reportedly triggers a $539 service bill without moving.

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Tesla owners who press Activate on Emergency Drive Away may be on the hook for a service bill even if their car never leaves the Supercharger stall.

Yaro, who posts about Tesla service cases on X as @Tutrifour, said a customer called after tapping Activate while still plugged into a Supercharger. The owner was about to pull away, remembered the cable was still connected and stopped. The car never moved, but the touchscreen showed a red alert reading “Emergency Drive Away has been activated” with “Service is required” underneath. A Service Mode screenshot showed the active alert BMS_a228_EmergencyDriveAwayServiceRequired, which Yaro said only Tesla Service can clear.


The cost of clearing it was the bigger surprise. “Don’t press Activate on the new Emergency Drive Away feature on your Tesla because service charges $539 to inspect the charge port and to clear the alert. Yes, even if you didn’t move the car an inch,” Yaro wrote.  The $539 figure comes from that single case, and Tesla has not published a set price for the inspection or commented on the post. Yaro also noted that the car would still charge with the alert on screen.

Tesla launched Emergency Drive Away on October 1 with software update 2026.38.3, letting drivers pull away from a U.S. Supercharger with the cable still attached, as Teslarati reported. To use it, a driver shifts into Drive while connected, holds the brake and taps Activate. The prompt warns that driving with the cable connected will damage the vehicle and the Supercharger, and that short camera recordings will be shared with Tesla.

Tesla Charging has been clear about what follows a real activation. Repairs to a Supercharger stall can run up to $25,000 depending on the site, a service visit for the car’s charge port is mandatory, and deliberate misuse “will invoke additional penalties.” What the company had not spelled out is that the service requirement is triggered the moment Activate is pressed, not the moment the cable breaks away.

From an engineering standpoint, that is the cautious choice. Once Activate is pressed, the car cannot be sure the charge port latch was not stressed, so flagging it for inspection removes the guesswork. It also means the button carries a price on its own, which is a stronger deterrent against casual use than any warning screen.


The report follows the feature’s first known real world use, when a driver in Austin during F1 weekend appeared to trigger it by accident and dragged the Supercharger cable along with the car. The Reddit user who filmed it said the driver seemed to have only half read the prompts.

For owners, the takeaway is to treat the red prompt as a stop sign. If it appears after shifting out of Park by mistake, shift back and unplug the normal way from the touchscreen, the Tesla app or the button on the charge handle. Activate is meant for moments when staying at the stall is the bigger risk, and Tesla is now pricing it that way.

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