News
Stoke Space to build SpaceX Raptor engine’s first real competitor
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.
The update that's rolling out to the fleet makes full use of the front and rear steering travel to minimize turning circle. In this case a reduction of 1.6 feet just over the air— Wes (@wmorrill3) April 16, 2024
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.
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.
SpaceX just picked up another $1.6 billion from the Pentagon, with the U.S. Space Force awarding two task orders worth $1.6 billion to fly 18 Falcon 9 missions from Vandenberg Space Force Base in California through the end of 2027. The launches will carry satellites for the Space Based Sensing and Targeting portfolio, a set of programs meant to help the military detect and track airborne threats and relay that information across forces in near real time.
The award falls under National Security Space Launch Phase 3 Lane 1, the Space Force’s faster, commercial style procurement track for missions that do not require the military’s most demanding certification process. It is also the largest single order publicly disclosed under that program so far, and the first task order issued since the Space Force nearly tripled Lane 1’s contract ceiling from $5.6 billion to $17 billion on July 17.
SpaceX to become America’s Military data backbone for missiles, drones, and warfighters
Eric Zarybnisky, the Space Force’s acting portfolio acquisition executive for space access, said the entire process, from identifying the requirement to signing the contract, took about two months, including a month set aside for companies to prepare proposals.
SpaceX is not just launching these satellites. It already holds the contracts to build two of the programs within the same portfolio, $4.16 billion for the Space Based Airborne Moving Target Indicator system and $2.29 billion for the Space Data Network Backbone, which Teslarati covered in May. That means SpaceX is now responsible for both building key pieces of the military’s next generation sensing network and getting them into orbit.
With this latest award, SpaceX’s Pentagon contract total for 2026 alone tops $8 billion, adding to a defense portfolio that already includes the Golden Dome missile defense software group SpaceX joined in April and a string of GPS launches it inherited after ULA’s Vulcan rocket ran into a booster anomaly, which we detailed in March.
Lane 1’s vendor pool technically includes seven companies: SpaceX, ULA, Blue Origin, Rocket Lab, Stoke Space, Impulse Space, and Relativity Space. In practice, SpaceX remains the only provider with the combination of launch cadence, flight proven Falcon 9 hardware, and West Coast infrastructure to support a campaign requiring roughly one Vandenberg launch a month for the next year and a half.
Some lawmakers have flagged the growing concentration of national security launches with one company as a risk worth watching. For now, the Space Force keeps backing SpaceX, with it being the company that shows up ready to launch.
Elon Musk shed two new bits of detail on Starship following its 13th test launch, which was an overwhelming success.
SpaceX launched Starship for the 13th time last Friday after two delays: one on Monday when several Raptor engines did not ignite, and another on Thursday due to unfavorable weather conditions in Starbase, Texas.
The launch was overwhelmingly successful. SpaceX was able to complete a necessary test of the heat shield tiles by increasing the acceleration of Starship from launch throughout the flight; 20 Starlink v3 satellites were released with no issue; the Super Heavy Booster landed safely in the Gulf of America, Ship successfully reignited engines while in space; and it also splashed down without incident in the Indian Ocean.
SpaceX Starship just nailed something it’s never done before
Nevertheless, more details are coming out about Starship, and Musk is doing the talking.
Starship Will Be Retrieved in the Ocean
Musk revealed on Tuesday night that Starship would be recovered by a ship in the Indian Ocean. SpaceX routinely tries to recover Starship after splashdown in an effort to find out more about the flight by examining the spacecraft afterward.
We’re sending a ship out to recover Starship https://t.co/fUqUZTITO9
— Elon Musk (@elonmusk) July 28, 2026
This helps engineers find out more about why things might have happened, allows them to examine any potential damage or anomalies that might have occurred, and increases the chances of an even more successful flight next time thanks to the additional information recovered.
Ship Could Have Been Caught by Tower Arms, Musk claims
Musk has already indicated that SpaceX will plan to attempt a catch of Starship with the 14th test flight. While this would be a major accomplishment, it would be an expected next step, considering the fact that the Super Heavy Booster has already been caught by the chopsticks on numerous occasions.
The ship landing was precise, meaning that it would have been caught by the tower arms https://t.co/6nbNrRfX9P
— Elon Musk (@elonmusk) July 29, 2026
A ship catch would be a great indication of where SpaceX stands in terms of reusability and launch cadence. A successful catch with relatively no incidents would be a good sign that SpaceX is nearing a more frequent launch of Starship, but also that the reusability of the massive rocket would be something many would expect in the near future.
It is a necessity to make life multiplanetary.
Elon Musk has updated his timeline for when humans will walk on Mars and for when ships will simply get there.
The objective of getting to Mars has been one of Musk’s biggest goals since becoming a serial entrepreneur and realizing that time on Earth is limited. Musk has said several times he hopes to die on Mars, and not by impact.
Musk now believes that people will be on Mars in “roughly 5 to 7 years.” He said that a Mars lander will get there “a few years sooner.”
People on Mars in roughly 5 to 7 years.
Mars lander a few years sooner.
— Elon Musk (@elonmusk) July 29, 2026
The response from Musk comes after NASA Administrator Jared Isaacman said that SpaceX’s biggest priority is the Moon and not Mars. Because of this, Isaacman conceded that he believes nuclear power and propulsion investments will provide “potentially the pathway with the fewest miracles required to put four people on Mars in the next 10 to 15 years.”
Of course, this is what NASA can do through taxpayer funding and nuclear investments, he added.
Musk’s grand ambitions are much more optimistic than most, and it is certainly a double-edged sword. This is not the first time timelines for Mars have been somewhat lofty, especially to those normal thinkers like you and me, not super geniuses like Musk.
In fact, the SpaceX and Tesla frontman has said on at least a dozen occasions that we could be on Mars in the coming years. Musk said 2020 would be the big year as early as 2009. In 2020, he was “highly confident” of a landing in 2026, and had even said 2024 in a best-case scenario.
The point is, the range has varied, and it’s anyone’s guess when we’ll get there. This latest adjustment to the timeline is typical of Musk, and while the Moon has seemingly taken priority over Mars, it is still worth mentioning that the ultimate goal is to make life multiplanetary, and it starts potentially with the Red Planet.
SpaceX scores another massive Pentagon deal to support military satellites
Elon Musk sheds two new bits of detail on Starship after 13th test launch
