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Ex-SpaceX engine expert to help design rockets built for launch on world’s largest jet
Stratolaunch, an aerospace company funded by Microsoft-made billionaire Paul Allen to build the world’s largest flightworthy aircraft, has announced a decision to build its own liquid-fueled rockets, to be air-launched from the aforementioned mega-plane.
Targeting an inaugural launch of the first version of the rocket – currently nicknamed “Kraken” – as early as 2022, Stratolaunch has chosen Jeff Thornburg, formerly SpaceX’s Vice President of Propulsion Engineering and the father of the company’s Mars-focused Raptor engine, to lead its foray into in-house rocket propulsion development and manufacturing.
Stratolaunch has confirmed what most people have long speculated: it’s developing its own launch vehicles for its air-launch system, including a reusable space plane that could eventually carry people. pic.twitter.com/nF9lKVe4xk
— Jeff Foust (@jeff_foust) August 20, 2018
But first: building the world’s largest aircraft
Stratolaunch’s first task at hand, however, is to begin flight-testing the largest (hopefully) operational aircraft in history, a prerequisite for the company’s longer-term orbital rocket and spaceplane aspirations. Nicknamed “Roc” after a mythical (and fictional) bird so large it could carry an elephant, the plane certainly lives up to its namesake. Featuring a full six of the same engines that power Boeing’s once-record-breaking 747 airliner and a wingspan that could easily fit three smaller 737 airliners with room to spare, it is genuinely difficult (if not impossible) to successfully convey the sheer scale of Roc outside of witnessing it in person.
Stationed in California’s Mojave Desert, the aircraft’s one and only copy is, for the most part, completed and has spent the brunt of 2018 conducting runway taxi tests, hopefully culminating in an inaugural flight test later this year or early next year. Designed to lift orbital-class rockets weighing as much as 250 metric tons (550,000 lb) to an altitude of at least 9100 meters (30,000 feet), the primary benefit of using aircraft as launch platforms derives from the simple fact that the atmospheric density at 30,000 feet is more than three times less than that at sea level. Similar to aircraft, rocket performance dramatically improves as atmospheric density decreases: less atmosphere means lower drag and pressure.
Rockets that launch from sea-level have to grapple with the difficulties of Earth’s relatively thick atmosphere at that height, with major launch events like “Max-Q” being big concerns almost solely because the dense air exerts major forces on launch vehicles and demands extreme measures like throttling down booster engines (very inefficient) and optimizing structures for aerodynamic efficiency despite the fact that rockets spend very little time operating in a significant atmosphere.
A launch pad without a rocket (sort of)
However, the simple fact of the matter is that billionaire Paul Allen’s colossal aircraft essentially does not have a single air-launched rocket in the world that can properly take advantage of its capabilities. Originally sized and designed with an air-launched version of SpaceX’s Falcon 9 in mind, that relationship folded amicably after roughly a year (2012), at which point SpaceX realized it would need to almost completely redesign a unique variant of Falcon 9. Your author will readily admit that they have admired the insanity of such a massive plane while still severely doubting its practical utility.
Thankfully, it appears that Allen is adamantly opposed to the idea that Stratolaunch is some silly whim to build the world’s largest plane. Rather, he is exceptionally reserved and pragmatic when discussing the aerial launch platform, according to a recent and extensive interview by Wired Magazine’s Steven Levy.
“Allen isn’t one to show exuberance, and when he speaks about the plane he focuses on its future utility. ‘When you see that giant plane, it’s a little nutty,’ he says. ‘And you don’t build it unless you’re very serious, not only about wanting to see the plane fly but to see it fulfill its purpose. Which is getting vehicles in orbit.’ – Paul Allen, 2018
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- Stratolaunch’s Roc shown with a triplet of Orbital ATK Pegasus XL rockets. (Vulcan Space)
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- Back in 2012, SpaceX briefly entertained the idea of a Falcon 9 variant optimized for air-launch, potentially including crew rating the rocket down the road. (Stratolaunch/Dynetics)
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- The Roc is inconceivably vast. (Stratolaunch)
Currently, Orbital ATK’s (now Northrop Grumman Innovation Systems) air-launched Pegasus XL rocket is the only “customer” in the world that can realistically use Stratolaunch as a launch platform, not exactly an impressive or sustainable launch vehicle with a maximum performance of less than 450 kg (~1000 lbs) to low Earth orbit for an incredible ~$40 million per (expendable) flight.
To answer that call and ensure Stratolaunch’s utility, the company reportedly began seriously considering its own in-house expendable and reusable rockets and propulsion systems sometime in 2016, plans that have since grown concrete and been publicly embedded into Stratolaunch’s overarching mission. Nicknamed “Kraken” after the mythical sea monster, the company hopes to develop an initially expendable rocket system capable of launching 3400 – 6000 kg (~7500 – 13250 lbs) into low Earth orbit with single booster and triple booster variants. Further down the line, Stratolaunch is eyeing the design and production of a fully and rapidly reusable orbital spaceplane, potentially including a version that would carry astronauts into space.
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- A concept video produced by Stratolaunch shows the Roc launching a Kraken rocket. (Stratolaunch, via Wired)
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- A concept video produced by Stratolaunch shows the Roc launching a Kraken rocket. (Stratolaunch, via Wired)
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- A concept video produced by Stratolaunch shows the Roc launching a Kraken rocket. (Stratolaunch, via Wired)
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- SpaceX’s subscale Raptor engine has completed more than 1200 seconds of testing in less than two years. (SpaceX)
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- BFS (circa 2017) shows off its complement of SL and Vacuum Raptor engines. SpaceX is moving back to something similar to this. (SpaceX)
Normally, one might simply roll their eyes at yet another startup touting small(ish) expendable rockets with first launches no earlier than the early 2020s – the market is getting to be absurdly and impossibly overcrowded at this point. However, Stratolaunch differs for one fundamental and reason: they have placed ex-SpaceX propulsion executive and expert Jeff Thornburg at the helm of the company’s freshly public rocket propulsion wing. While at SpaceX, Mr. Thornburg spent all but one of his five years with the company (2011-2015) single-mindedly focused on the development and engineering of all aspects of the Raptor rocket engine, a next-generation propulsion system designed to enable SpaceX’s sustainable colonization of Mars.
Raptor is an exceptional rocket engine thanks in no small part to Thornburg’s brilliance as a propulsion engineer, and that same brilliance and half-decade of experience at the most successful rocket startup in existence could ultimately prove a massive boon for Stratolaunch’s otherwise interesting but unexceptional expendable rocket concepts.
Put simply, under Jeff Thornburg’s direction and with access to founder Paul Allen’s considerable wealth, Stratolaunch is undoubtedly worth keeping a close eye in the future, both far and near.
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Elon Musk said he is planning to give “every one of his SpaceX shares to every kid in America” in 2027, stating that “this will be the first of many.”
SpaceX went public earlier this year, and its stock price has been relatively stable since leveling off shortly after its IPO. Based on its current price, it’s a gift of just over $10 billion to children across the United States.
It appears to be closely related to President Donald Trump’s bank accounts for children, which were set up earlier this year as Trump Accounts.
Just hours earlier, Anthropic had announced the establishment of its Anthropic Public Benefit Fund, “a new wholly-owned entity dedicated entirely to public benefit.” Musk responded by stating he recommended “giving the shares directly to the public,” and that he would be doing it that way.
Just a little bit later, Musk said children across the U.S. would be getting a share from him:
Next year, I will give one of my SpaceX shares to every kid in America.
This will be the first of many.
— Elon Musk (@elonmusk) October 19, 2026
There are roughly 70 million children, meaning someone under the age of 18, in the United States, according to the Federal Interagency Forum on Child and Family Statistics. Musk’s ownership of SpaceX stock shows he has around 849 million Class A shares of SpaceX stock, according to filings with the SEC.
Elon Musk revealed in a post on X that “Permits were impossible to get,” explaining the fate of The Boring Company’s most ambitious East Coast proposal.
The comment responded to a query about what became of his July 20, 2017 announcement that he had “just received verbal govt approval” for an underground Hyperloop connecting New York City, Philadelphia, Baltimore, and Washington, D.C., capable of carrying passengers from the Big Apple to the Nation’s Capital in just 29 minutes.
The Boring Company receives verbal ‘approval’ to build NY to DC Hyperloop tunnel
The 2017 post, which envisioned city-center stations and multiple elevators in each city, sparked immediate scrutiny. Local and state officials in New York, Philadelphia, Baltimore, and D.C. said they had no knowledge of any approval. A White House spokesperson confirmed only “promising conversations” about the transformative infrastructure.
Musk clarified shortly after that there was “still a lot of work” to do for formal approvals.
@cybrtrkguy Permits were impossible to get
— Elon Musk (@elonmusk) October 19, 2026
Limited progress followed, as Maryland Governor Larry Hogan’s administration issued a conditional utility permit and supported work near Fort Meade. In 2018, Washington, D.C., granted a preliminary permit for site preparation and excavation on a vacant lot at 53 New York Ave. NE in the NoMa neighborhood, which The Boring Company said could become a station.
A draft environmental assessment for a D.C.-Baltimore segment was released in 2019. Yet, by April 2021, the company had removed the project from its website, and the Federal Highway Administration reported receiving no indication of further interest. Communication with Maryland officials had ceased.
The full corridor would have required coordination among the District of Columbia, Maryland, Pennsylvania, New York, the Federal Highway Administration, the Army Corps of Engineers, the National Park Service, and other agencies.
Environmental reviews under the National Environmental Policy Act, utility clearances, and approvals for novel infrastructure added to the overall complexity of the project and its approval.
Speculation on the permitting barriers centers around a few factors, but a multi-state, multi-level route involving unproven high-speed vacuum-tube technology inherently triggers exhaustive safety, environmental, and engineering reviews that can stretch for years, even for conventional projects.
There are also other elements, of course, like officials who may face political exposure if a privately funded, untested system encountered anything such as cost overruns, delays, or safety issues. On the outset of this project, there were limited things such as engineering plans or demonstrated technology maturity, which also added to the potential skepticism.
The East Coast vision for Boring Co., once framed as a privately funded revolution that could reshape Northeast travel, quietly ended without construction of the promised network. Musk’s recent statement frames the outcome as a regulatory impasse, unfortunate but not unexpected.
Tesla CEO Elon Musk took to his social media platform X on Sunday to remind everyone that the Roadster’s true meaning is not about company growth or adding dollars to shareholders’ pockets. Sometimes, you just do things because you can.
Following the Roadster’s epic unveiling event last Thursday, skeptics and critics of the company or the project itself came out to say that the vehicle is a pointless project because it is not geared toward growing the company, delivering supreme margins for profitability, nor does it contribute to the big picture of Artificial/Super Intelligence.
But that’s just the thing: Roadster is not meant to be some shareholder dream; it’s meant to be a vehicle that people buy just because it is something awesome, unique, and the first of its kind.
Tesla Roadster: Three configs, one can fly, 0-60 in 0.8 seconds
Musk had to remind those who are skeptical about the Roadster’s importance to the company mission that while it is not a major contributor to Tesla’s long-term goals, it is something that is being built just because it can be:
“Optimus and Cybercab will be the vast majority of Tesla’s value. The only things that will scale to incredible size (K2 and beyond) economically are super intelligence, robots, solar power, and mass to space. And, of course, if you have the first two, the rest will follow. But Roadster is super cool, so we’re doing it anyway.”
Musk has said on many occasions that Optimus would be the project that would make up the vast majority of Tesla’s value in the coming years.
Robotics will be a major focus of Tesla over the coming years, especially as Musk believes Optimus will enable work to be optional for humans and will enable what he calls “High Universal Income.”
Optimus and Cybercab will be the vast majority of Tesla’s value.
The only things that will scale to incredible size (K2 and beyond) economically are super intelligence, robots, solar power and mass to space.
And, of course, if you have the first two, the rest will follow.
But Roadster is super cool, so we’re doing it anyway.
— Elon Musk (@elonmusk) October 18, 2026
Cybercab will be a passive income opportunity for owners, Musk and Tesla have said for a very long time, as a fleet of self-driving vehicles will operate within a ride-hailing Robotaxi service that won’t require a human driver to be present.
Tesla investors are more than enthusiastic about the company’s future projects, at least from a general consensus perspective. However, it is important to note that the Roadster is a fun and cool project that pushes the boundaries of what people thought was possible for an automobile.
What we saw last week was the first true example of a flying car, and despite the backlash about how it might not contribute to Tesla’s grand ambitions, it’s okay to have fun sometimes, too.
Elon Musk will give ‘every kid in America’ a SpaceX share in 2027
Elon Musk reveals why Boring Co’s biggest East Coast project never happened
Tesla CEO Elon Musk reminds everyone about Roadster’s true meaning
SpaceX reveals how its 1 Million AI satellite network will work and prevent space collisions
Tesla Roadster: Three configs, one can fly, 0-60 in 0.8 seconds
