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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
Elon Musk just set a condition that could end Falcon 9 as we know it
Elon Musk says SpaceX will finally retire Falcon 9 once Starship flies reliably every week.
Elon Musk gave the clearest timeline yet for retiring Falcon 9, SpaceX’s workhorse rocket.
The comment came in a reply on X, where Musk wrote that “once Starship is flying reliably several times per week, it makes sense to shift super scarce SpaceX engineering and production resources to Starship to get launch rate to several times per day, which means winding down Falcon.” He was responding to physicist Casey Handmer, who noted that NASA is reportedly uneasy about SpaceX phasing out Falcon after building what Handmer called the most successful launcher ever, with the fleet nearing 1,000 total launches.
Now @SciGuySpace reports NASA is in a tizzy because after running the most successful launcher ever for more than a decade and nearing 1000 launches, @SpaceX is planning to retire Falcon in favor of Starship in a few years.
Sorry, NASA, you’ve had 15 years to burn down the… https://t.co/uCNoMwK0v9
— Casey Handmer (@CJHandmer) August 22, 2026
Falcon 9 is still SpaceX’s busiest vehicle by far. The company is on pace for roughly 140 to 145 Falcon flights this year, following 165 in 2025, president Gwynne Shotwell told Time earlier in 2026. She has already said Falcon flights would “tail off” as Starship comes online, while reports indicate that SpaceX has stopped booking new Falcon 9 launches past 2028 and halted production of some expendable Falcon hardware, according to Bloomberg.
It’s worth noting that Musk’s post is a condition, and not a countdown on when Falcon will retire. Starship has not yet flown weekly, let alone daily. Its most recent flight in July ended with a soft splashdown in the Indian Ocean, a milestone Musk pointed to earlier this month when he said the vehicle’s heat shield problem was effectively solved. SpaceX towed that ship to Christmas Island for inspection, and the next flight, Flight 14, is aimed at putting Starship into orbit for the first time. A tower catch attempt for the upper stage has been pushed back to what Musk has called “a few months” away.
SpaceX and a new Trump order that could rewrite the next decade of launches
The gap between Falcon’s role today and Starship’s promised role tomorrow matters most to NASA. Falcon and its Dragon capsule remain the only way the agency rotates astronauts to and from the International Space Station, and Starship is not certified to carry NASA crews. Musk’s post did not address how that handoff would work if Falcon winds down before a crew-rated Starship variant exists. The timing lines up with Musk’s other recent Starship comments. Two days before the Falcon post, he told a different X user that SpaceX is aiming for more than 30 Starship launches a day by 2030, or roughly 10,000 a year, a figure tied to the Trump administration’s new push for higher national launch cadence. Falcon, which took over a decade to reach its first 100 launches, was never built to approach that kind of volume.
For now, Falcon 9 keeps flying at a near-record pace while Starship works to prove it can do the job Musk has already picked out for it.
Tesla Cybercab is set to launch in Austin, Texas, on September 3, as the company has officially started sending out invitations to a dedicated event it will hold in the city where its headquarters is located.
The Cybercab is Tesla’s dedicated ride-sharing vehicle: it features just two seats and has no steering wheel or pedals. It is aimed at fully autonomous passenger transport, and will operate in the Robotaxi fleet alongside the Tesla Model Y, which has been performing driverless rides for real-world passengers for more than a year.
Thank you so much @Tesla for inviting us to the Cybercab launch in Austin! 🤠 pic.twitter.com/F1rAR8zd5O
— TESLARATI (@Teslarati) August 22, 2026
The launch of the Cybercab marks the next chapter in Tesla’s autonomy story. The company has been developing autonomous transport for years with its Full Self-Driving (Supervised) platform, which is available in any vehicle the company has built with the proper hardware and software capabilities.
Its capabilities vary by hardware and software version, but Tesla says its latest hardware version, known as AI4, can deliver full autonomy. However, future vehicles will operate with even more robust hardware packages, as Tesla will develop AI4.5 and AI5 for even more capability in its vehicles.
Following a report from The Information that surfaced earlier this week, the writing was on the wall that Tesla was set to launch Cybercab in the near term. The report stated Tesla could launch Cybercab as soon as the end of August. Tesla came close and has booked it for September 3.
The big thing with this event being scheduled is not necessarily that Tesla is launching a new vehicle, but instead that it is launching a vehicle that has no steering wheel or pedals and will operate exclusively on a self-driving program that is evidently nearing full autonomy. If the event allows vehicles to take passengers on public roads and drop them off wherever they please within the City of Austin, it will be a drastic advancement in the company’s self-driving story.
People have ridden in Cybercab previously: Tesla had the “We, Robot” event in October 2024, which allowed people to experience fully autonomous rides in a closed circuit at Warner Bros. Studios in Burbank.
🚨 Ride in a Tesla Cybercab with us
— TESLARATI (@Teslarati) May 11, 2025
Additionally, Tesla launched employee rides in Cybercab in July.
It’s a drastic step forward for Tesla, whose CEO, Elon Musk, has promised for years that the company would release a fully autonomous vehicle and platform capable of allowing drivers to relinquish any responsibility behind the wheel.
Elon Musk put a number on where he thinks SpaceX’s Starship program is headed by 2030, replying on X a day after President Trump signed a memo pushing the country toward 1,000 space launches and reentries a year.
The exchange started when Aaron Burnett, co-founder of propulsion startup Mach 33, posted that “1,000 launches/reentries is the goal,” quoting White House science adviser Michael Kratsios on the newly signed National Space Transportation Policy. Burnett noted that the FAA’s own bull-case forecast reached only 385 annual launches by 2030, while his firm’s conservative model already put SpaceX alone near 940. Musk responded, “We’re aiming to reach 30+ Starship launches/day in 2030, which is ~10k annualized. Still tiny numbers compared to airplane flights!”
We’re aiming to reach 30+ Starship launches/day in 2030, which is ~10k annualized.
Still tiny numbers compared to airplane flights!
— Elon Musk (@elonmusk) August 21, 2026
That figure is specific to Starship, the rocket SpaceX is still developing for orbital and lunar missions, not the Falcon 9 fleet that carries most of the company’s current launch volume. Starship has flown twice this year, a slower pace than the four and five flights SpaceX managed in 2024 and 2025. Getting from two flights a year to 30 a day is the scale of jump the new federal policy is meant to clear regulatory room for.
Trump’s memo, signed Thursday, directs agencies to identify new launch and reentry sites on federal land, including a new reentry site within 90 days, and to speed up the permitting and environmental reviews that have long slowed cadence growth. It also sets a goal of returning American astronauts to the moon by 2028 and placing initial lunar base elements by 2030, tying the launch buildout directly to NASA’s Artemis program.
SpaceX has already been pushing the FAA toward higher numbers on its own. The agency approved up to 44 annual Starship launches from Kennedy Space Center in February, on top of a 2024 review that raised the cap at Starbase in Texas to 25 a year. Those approvals cover a fraction of the 10,000 annual flights Musk is now describing, which shows how far current permitting still sits from the administration’s stated target.
The near-term test of all this is more modest. SpaceX cleared a full-duration, six-engine static fire on its next Starship vehicle this week, the last major hardware checkpoint before Flight 14, which is targeting no earlier than August 28 and is expected to attempt the vehicle’s first full orbital mission. Musk said last week that a tower catch of the upper stage is still probably months away, a reminder that the immediate roadmap remains far more incremental than the daily launch numbers he just posted.
Elon Musk just set a condition that could end Falcon 9 as we know it
Tesla will launch Cybercab on September 3
