News
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
-
- Stratolaunch’s Roc shown with a triplet of Orbital ATK Pegasus XL rockets. (Vulcan Space)
-
- 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)
-
- 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.
-
- A concept video produced by Stratolaunch shows the Roc launching a Kraken rocket. (Stratolaunch, via Wired)
-
- A concept video produced by Stratolaunch shows the Roc launching a Kraken rocket. (Stratolaunch, via Wired)
-
- A concept video produced by Stratolaunch shows the Roc launching a Kraken rocket. (Stratolaunch, via Wired)
-
- SpaceX’s subscale Raptor engine has completed more than 1200 seconds of testing in less than two years. (SpaceX)
-
- 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!
Elon Musk
SpaceX’s next Starship launch is about to attempt its biggest leap yet
SpaceX targets September 22 for Starship Flight 14, its first attempt to reach real orbit.
SpaceX has set September 22 as the target date for Starship’s 14th test flight, and this one carries a different goal than any of the 13 that came before it. Every previous Starship mission has intentionally flown a suborbital arc, reentering the atmosphere within the same hour it launched. Flight 14 is designed to send the craft into a genuine orbit around Earth for the first time.
The launch window opens at 7:15 a.m. Central time at Starbase in South Texas and runs for 75 minutes, pending regulatory approval, according to SpaceX’s mission description published Tuesday. If the flight goes as planned, Starship will circle the planet roughly six times at an altitude near 275 kilometers over about ten hours before a deorbit burn sends it toward a splashdown in the Pacific Ocean west of Chile, a departure from the Indian Ocean recoveries used on the last several flights.
The mission also marks the first attempt to put a working batch of Starlink V3 satellites into actual service. Flight 13 carried 20 of the new satellites in July, but because that mission never left a suborbital trajectory, the payload reentered along with the ship instead of separating into orbit.
SpaceX tells the FCC that Starship Flight 14 is going to orbit
Each V3 satellite is rated for roughly one terabit per second of downlink capacity, so a successful deployment on Flight 14 would be SpaceX’s largest single jump in network bandwidth since Starlink began flying on Falcon 9.
Flight 13 still did the heavier lifting on the technical side. That July mission flew a deliberately more stressful reentry profile to test Starship’s heat shield, and the ship survived its softest splashdown yet, intact enough for drone inspections shortly after landing. Elon Musk said the flight delivered “all the heat shield data we needed and then some,” a result Teslarati covered in detail when he later said SpaceX had solved the vehicle’s biggest reusability challenge. Flight 14 is where SpaceX starts spending that confidence on an actual orbital insertion rather than another controlled fall back to Earth.
One thing Flight 14 will not attempt is a tower catch of the ship. Musk floated the idea right after Flight 13, but walked the timeline back in August, saying a catch attempt was more likely “in a few months.” The Super Heavy booster will still aim for its own recovery, targeting an offshore landing point in the Gulf of America, the same approach used on recent flights.
September 22 is SpaceX’s own target, not a locked date. Starship’s schedule has slipped before over hardware readiness and FAA sign off, and the company has said as much in its own mission notes. But the plan itself represents the clearest marker yet that Starship is moving from a suborbital test program into something meant to carry paying payloads and, eventually, people.
Elon Musk
Elon Musk gives his most telling Tesla-SpaceX merger conversation yet
Elon Musk hinted a Tesla-SpaceX merger could be coming, and Wall Street is taking notice.
Elon Musk gave his clearest signal yet that Tesla and SpaceX could eventually combine, telling the All-In Summit in Los Angeles that the two companies’ deepening collaboration makes the question worth asking. Sawyer Merritt first surfaced the highlight on X Tuesday.
Asked directly why Tesla and SpaceX remain separate given how closely they already work together, Musk told hosts at the summit: “Great question there. With all this collaboration, on so many levels, who can imagine what action one might take when there’s so much close collaboration in so many areas.” SpaceX President Gwynne Shotwell, who joined Musk on stage, added that SpaceX personnel have already moved into xAI to fill leadership and engineering gaps, saying the businesses are integrating “faster than I thought,” though “not fully integrated yet,”
The comments landed on top of merger speculation that has been building on Wall Street for months. JPMorgan has called a tie-up “strategically coherent on paper,” pointing to overlapping ambitions in AI, robotics, energy, transportation and space. Jefferies went further, estimating Musk could retain roughly 55.3 percent voting control in a deal structured without a premium, a scenario that would still leave room for Tesla shareholders to come out ahead. On Kalshi, traders now put the odds of a merger before 2028 at 66 percent.
Tesla’s stake in SpaceX, still under one percent, traces back to its earlier investment in xAI, which converted to SpaceX equity after SpaceX absorbed the AI company. The two are also jointly building Terafab, a chip facility in Austin meant to serve both Tesla’s AI computing needs and SpaceX’s satellite ambitions. Wedbush analyst Dan Ives has stood by a 2027 merger timeline for months, and Cathie Wood’s ARK Invest recently floated a similar case, an idea Musk pushed back on directly at the time.
Another Tesla SpaceX merger prediction by ARK Invest has Elon Musk talking
The timing adds another layer. Tesla has scheduled an October 1 unveiling for its next generation Roadster at a venue near SpaceX’s McGregor, Texas test site, using the phrase “Go for launch” in its promotional material. Both stocks dipped roughly 2 percent Monday before recovering slightly in premarket trading Tuesday, with SpaceX shares up about 0.4 percent and Tesla essentially flat.
Musk stopped short of confirming anything is in motion. But unlike his past denials of a corporate restructuring, this response didn’t rule one out, and it came with Shotwell sitting next to him describing an integration that’s already underway.
The Tesla Roadster unveiling is getting hyped up by the company’s CEO Elon Musk, who has been a big reason the product has such high expectations due to delayed timelines and a constant need to make it even more insane than before.
Tesla announced on September 12 that it would officially unveil the Roadster in Waco, Texas, on October 1, ending years of patience for fans and reservation holders who have waited for the all-electric supercar to enter production since 2017.
Musk has said that this event will be well worth the wait on several occasions, and last year on the Joe Rogan Experience, he said that there should be a closing chapter to supercars- the end of cars that aren’t focused on safety.
He said:
“Whether it’s good or bad, it will be unforgettable. My friend Peter Thiel once reflected that the future was supposed to have flying cars, but we don’t have flying cars. I think if Peter wants a flying car, he should be able to buy one. I think it has a shot at being the most memorable product unveil ever. This is some crazy technology in this car. Let’s just put it this way: if you took all the James Bond cars and combined them, it’s crazier than that.”
Musk’s teases have continued, and now that the event is roughly two weeks away, it seems like Roadster is finally going to show up and blow some minds:
It’s out of this world
— Elon Musk (@elonmusk) September 13, 2026
Excitement guaranteed
— Elon Musk (@elonmusk) September 13, 2026
Tesla has definitely dragged out the development of the Roadster, but there is a good reason for it.
Tesla has been working on many other projects, most notably self-driving efforts to increase passenger safety, and those simply took priority over the Roadster, a low-volume, high-performance sports car that has a lightning-fast acceleration rate of 0-60 MPH in just 1.1 seconds, could potentially fly, and contributes very little to the company’s mission.
However, many people have the Roadster on pre-order through the referral program or with their own money, and it is time that Tesla delivers on that.
SpaceX’s next Starship launch is about to attempt its biggest leap yet
Elon Musk gives his most telling Tesla-SpaceX merger conversation yet
