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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.
For prompt updates, on-the-ground perspectives, and unique glimpses of SpaceX’s rocket recovery fleet check out our brand new LaunchPad and LandingZone newsletters!
Tesla analyst Gary Black of The Future Fund claims that the company is making a big mistake getting rid of the Model S and Model X. Instead, he believes another vehicle within the company’s lineup should be discontinued: the Cybertruck.
Black divested The Future Fund from all Tesla holdings last year, but he still covers the stock as an analyst as it falls in the technology and autonomy sectors, which he covers.
In a new comment on Thursday, Black said the Cybertruck should be the vehicle Tesla gets rid of due to the negatives it has drawn to the company.
The Cybertruck is also selling in an underwhelming fashion considering the production capacity Tesla has set aside for it. It’s worth noting it is still the best-selling electric pickup on the market, and it has outlasted other EV truck projects as other manufacturers are receding their efforts.
Black said:
“IMHO it’s a mistake to keep Tesla Cybertruck which has negative brand equity and sold 10,000 units last year, and discontinue S/X which have strong repeat brand loyalty and together sold 30K units and are highly profitable. Why not discontinue CT and covert S/X to be fully autonomous?”
IMHO it’s a mistake to keep $TSLA Cybertruck which has negative brand equity and sold 10,000 units last year, and discontinue S/X which have strong repeat brand loyalty and together sold 30K units and are highly profitable. Why not discontinue CT and covert S/X to be fully…
— Gary Black (@garyblack00) January 29, 2026
On Wednesday, CEO Elon Musk confirmed that Tesla planned to transition Model S and Model X production lines at the Fremont Factory to handle manufacturing efforts of the Optimus Gen 3 robot.
Musk said that it was time to wind down the S and X programs “with an honorable discharge,” also noting that the two cars are not major contributors to Tesla’s mission any longer, as its automotive division is more focused on autonomy, which will be handled by Model 3, Model Y, and Cybercab.
Tesla begins Cybertruck deliveries in a new region for the first time
The news has drawn conflicting perspectives, with many Tesla fans upset about the decision, especially as it ends the production of the largest car in the company’s lineup. Tesla’s focus is on smaller ride-sharing vehicles, especially as the vast majority of rides consist of two or fewer passengers.
The S and X do not fit in these plans.
Nevertheless, the Cybertruck fits in Tesla’s future plans. Musk said the pickup will be needed for the transportation of local goods. Musk also said Cybertruck would be transitioned to an autonomous line.
In a groundbreaking new report from Reuters, SpaceX is reportedly discussing merger possibilities with xAI ahead of the space exploration company’s plans to IPO later this year, in what would be a blockbuster move.
The outlet said it would combine rockets and Starlink satellites, as well as the X social media platform and AI project Grok under one roof. The report cites “a person briefed on the matter and two recent company filings seen by Reuters.”
Musk, nor SpaceX or xAI, have commented on the report, so, as of now, it is unconfirmed.
With that being said, the proposed merger would bring shares of xAI in exchange for shares of SpaceX. Both companies were registered in Nevada to expedite the transaction, according to the report.
On January 21, both entities were registered in Nevada. The report continues:
“One of them, a limited liability company, lists SpaceX and Bret Johnsen, the company’s chief financial officer, as managing members, while the other lists Johnsen as the company’s only officer, the filings show.”
The source also stated that some xAI executives could be given the option to receive cash in lieu of SpaceX stock. No agreement has been reached, nothing has been signed, and the timing and structure, as well as other important details, have not been finalized.
SpaceX is valued at $800 billion and is the most valuable privately held company, while xAI is valued at $230 billion as of November. SpaceX could be going public later this year, as Musk has said as recently as December that the company would offer its stock publicly.
The plans could help move along plans for large-scale data centers in space, something Musk has discussed on several occasions over the past few months.
At the World Economic Forum last week, Musk said:
“It’s a no-brainer for building solar-powered AI data centers in space, because as I mentioned, it’s also very cold in space. The net effect is that the lowest cost place to put AI will be space and that will be true within two to three years, three at the latest.”
He also said on X that “the most important thing in the next 3-4 years is data centers in space.”
If the report is true and the two companies end up coming together, it would not be the first time Musk’s companies have ended up coming together. He used Tesla stock to purchase SolarCity back in 2016. Last year, X became part of xAI in a share swap.
Tesla has announced it has hit a major milestone with Full Self-Driving subscriptions, shortly after it said it would exclusively offer the suite without the option to purchase it outright.
Tesla announced on Wednesday during its Q4 Earnings Call for 2025 that it had officially eclipsed the one million subscription mark for its Full Self-Driving suite. This represented a 38 percent increase year-over-year.
This is up from the roughly 800,000 active subscriptions it reported last year. The company has seen significant increases in FSD adoption over the past few years, as in 2021, it reported just 400,000. In 2022, it was up to 500,000 and, one year later, it had eclipsed 600,000.
NEWS: For the first time, Tesla has revealed how many people are subscribed or have purchased FSD (Supervised).
Active FSD Subscriptions:
• 2025: 1.1 million
• 2024: 800K
• 2023: 600K
• 2022: 500K
• 2021: 400K pic.twitter.com/KVtnyANWcs— Sawyer Merritt (@SawyerMerritt) January 28, 2026
In mid-January, CEO Elon Musk announced that the company would transition away from giving the option to purchase the Full Self-Driving suite outright, opting for the subscription program exclusively.
Musk said on X:
“Tesla will stop selling FSD after Feb 14. FSD will only be available as a monthly subscription thereafter.”
The move intends to streamline the Full Self-Driving purchase option, and gives Tesla more control over its revenue, and closes off the ability to buy it outright for a bargain when Musk has said its value could be close to $100,000 when it reaches full autonomy.
It also caters to Musk’s newest compensation package. One tranche requires Tesla to achieve 10 million active FSD subscriptions, and now that it has reached one million, it is already seeing some growth.
The strategy that Tesla will use to achieve this lofty goal is still under wraps. The most ideal solution would be to offer a less expensive version of the suite, which is not likely considering the company is increasing its capabilities, and it is becoming more robust.
Tesla is shifting FSD to a subscription-only model, confirms Elon Musk
Currently, Tesla’s FSD subscription price is $99 per month, but Musk said this price will increase, which seems counterintuitive to its goal of increasing the take rate. With that being said, it will be interesting to see what Tesla does to navigate growth while offering a robust FSD suite.
Tesla analyst claims another vehicle, not Model S and X, should be discontinued
SpaceX reportedly discussing merger with xAI ahead of blockbuster IPO
