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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.

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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.

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.

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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 Semi gets strange-but-understandable comparison from Jay Leno

In a recent interview with MotorTrend, legendary comedian and automotive enthusiast Jay Leno shared his impressions after driving Tesla’s long-range Semi truck, offering one of the most vivid descriptions to date:

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Credit: Jay Leno's Garage

The Tesla Semi recently received a strange-but-understandable comparison from automotive enthusiast and former long-time late-night television show host Jay Leno.

In a recent interview with MotorTrend, legendary comedian and automotive enthusiast Jay Leno shared his impressions after driving Tesla’s long-range Semi truck, offering one of the most vivid descriptions to date:

“It’s like driving an office building.”

The comparison may seem quirky—office buildings evoke images of immobility rather than motion—but it aptly conveys the experience of commanding a massive 23,000-pound Class 8 electric truck that delivers sports-car acceleration.

Lenotested the production-spec Long Range model, which is rated for up to 500 miles of range. He was visibly impressed by its performance, noting how the enormous vehicle moves with surprising urgency.

“It’s as fast as a Tesla, but it’s like driving an office building,” he remarked. “It’s this huge thing that moves like right now. You go 500 miles. You get 60% charge in 30 minutes. You’re saving on fuel costs. It seems quite good.”

The reaction highlights the cognitive dissonance at the core of the Tesla Semi. Traditional diesel semi-trucks are slow, noisy, and expensive to run. The Semi rewrites the rules with instant torque from its tri-motor electric powertrain, producing up to 800 kW.

Despite its size, the truck feels agile thanks to full electric steering assist, upgraded actuators borrowed from the Cybertruck, and a 48-volt electrical architecture that improves responsiveness and efficiency.

Tesla reports real-world energy consumption below 1.7 kWh per mile for the Long Range version. Megacharger stations can deliver a 60% charge in roughly 30 minutes, making the truck suitable for long-haul operations.

Additional features include an electric Power Take-Off (ePTO) capable of 25 kW for trailer refrigeration or other equipment, and a driver-focused cab with a central seating position for optimal visibility and a quiet, high-tech interior.

Fleet operators stand to benefit significantly from the economics. Diesel trucks often cost nearly one dollar per mile when including fuel, maintenance, and downtime.

Tesla projects the Semi can reduce operating costs to as low as 15 cents per mile through cheaper electricity, regenerative braking that minimizes brake wear, and reduced service requirements. While early deployments, like Pepsi’s, focused on shorter routes, the 500-mile variant targets cross-country applications.

Obstacles remain. A fully loaded tractor-trailer can reach 80,000 pounds, which reduces real-world range compared to the unloaded test conditions. Building out a nationwide Megacharger network will be essential for broader adoption. The Semi also carries a higher upfront price than conventional diesels, though total cost of ownership and available incentives frequently tip the scales in its favor over time.

Tesla Semi hauls fresh Cybercab batch as Robotaxi era takes hold

Leno’s “office building” description resonates because it captures the unexpected thrill of piloting something so large yet so capable. As the trucking industry faces pressure to cut emissions and control rising fuel expenses, the Semi offers a compelling alternative that excels in performance, comfort, and efficiency.

Coming from a man who has driven everything from vintage classics to modern hypercars, Leno’s genuine enthusiasm adds weight to the verdict.

The Tesla Semi is emerging as more than an experimental EV—it represents a practical vision for the future of heavy-duty transport where massive rigs accelerate instantly, and the numbers finally make sense. If fleet results continue to validate the claims, the era of diesel dominance could be drawing to a close.

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Tesla expands its mass-market color palette in the U.S.

Delivering a fresh splash of color to its lineup, Tesla is giving U.S. buyers two stunning new blue options that are already turning heads.

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Credit: Brand0n | X

Tesla has expanded the color palette it offers on its mass market vehicles in the United States, giving buyers of the Model 3 and Model Y a few additional options than before.

Delivering a fresh splash of color to its lineup, Tesla is giving U.S. buyers two stunning new blue options that are already turning heads. Starting on May 8, the automaker updated its North American configurator to introduce Marine Blue on Model Y Premium trims and Frost Blue exclusively on the Model 3 Performance.

The move replaces the long-running Deep Blue Metallic, a staple for over eight years, and brings previously exclusive shades stateside.

Marine Blue, a deep, rich oceanic hue formerly limited to Europe and Asia-Pacific markets, is now available on Model 3 and Model Y RWD and Long Range AWD Premium variants. Priced at a $1,000 upgrade—standard for Tesla’s premium paints—it delivers a sophisticated, metallic finish that shifts beautifully under light.

Tesla North America highlighted the change directly in an official post, confirming Marine Blue as the new flagship blue for non-Performance models.

Frost Blue, on the other hand, is the real crowd-pleaser for enthusiasts. Previously reserved for the flagship Model S and Model X, this lighter, icy metallic shade is now offered at no extra cost on Model 3 Performance and Model Y Performance trims.

Performance buyers effectively get a premium color included in the base price, a smart perk that Tesla has extended to higher-end variants across the board. Early in-person sightings and configurator renders show Frost Blue’s cool, modern vibe popping against the cars’ sleek lines, especially with black wheels and red brake calipers.

The timing couldn’t be better. With Tesla pushing refreshed Model 3 and Model Y refreshes amid growing competition, these updates add visual excitement without major redesigns.

Deep Blue Metallic orders are being transitioned to the new shades, according to customer reports and Tesla communications. In the U.S., Puerto Rico, and Mexico, the options are live now; Canada sees limited Frost Blue availability on the Model 3 Performance.

Tesla’s color strategy continues to evolve, borrowing from higher-end models to refresh mass-market EVs. Now that we bid farewell to the Model S and Model X, some of their colors might be available on the more widely available Model 3 and Model Y.

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Tesla Semi’s official battery capacity leaked by California regulators

A California regulatory filing just confirmed the exact battery size inside each Tesla Semi variant.

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A regulatory filing published by the California Air Resources Board in April 2026 has put official numbers on what Tesla Semi owners and fleet buyers have long wanted confirmed: the exact battery capacities of both the Long Range and Standard Range Semi truck variants. CARB is California’s independent air quality regulator, and it certifies zero-emission powertrains before they can be sold or operated in the state. When a manufacturer submits a vehicle for certification, the resulting executive order becomes a public document, making it one of the most reliable sources for confirmed production specs on any EV.

The document lists two certified powertrain configurations. The Long Range Semi carries a usable battery capacity of 822 kWh, while the Standard Range version comes in at 548 kWh. Both use lithium-ion NCMA chemistry and share the same peak and steady-state motor output ratings of 800 kW and 525 kW respectively. Cross-referencing Tesla’s published efficiency figure of approximately 1.7 kWh per mile under full load, the 822 kWh pack supports roughly 480 miles of real-world range, which aligns closely with Tesla’s advertised 500-mile figure for the Long Range trim. The 548 kWh Standard Range pack works out to approximately 320 miles, again consistent with Tesla’s stated 325-mile target.

Here is a direct comparison of the two versions based on the CARB filing and published specs:

Tesla Semi Spec Long Range Standard Range
Battery Capacity 822 kWh 548 kWh
Battery Chemistry NCMA Li-Ion NCMA Li-Ion
Peak Motor Power 800 kW 525 kW
Estimated Range ~500 miles ~325 miles
Efficiency ~1.7 kWh/mile ~1.7 kWh/mile
Est. Price ~$290,000 ~$260,000
GVW Rating 82,000 lbs 82,000 lbs

The timing of this certification is not incidental. On April 29, 2026, Semi Programme Director Dan Priestley confirmed on X that high-volume production is now ramping at Tesla’s dedicated 1.7-million-square-foot facility in Sparks, Nevada. A key advantage of the Nevada location is vertical integration: the 4680 battery cells powering the Semi are manufactured in the same complex, eliminating the supply chain bottleneck that had delayed the program for years.

Tesla’s long-term goal is to reach a production capacity of 50,000 trucks annually at the Nevada factory, which would represent roughly 20 percent of the entire North American Class 8 market. With CARB certification now in hand and the production line running, the regulatory and manufacturing groundwork for that target is in place.

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