Stratolaunch Names SpaceX Vet as Vice President of Propulsion

Jeff Thornburg

SEATTLE (Stratolaunch PR) — At Stratolaunch Systems Corp., we galvanize and enable smart people to tackle challenges head-on. I have named Jeff Thornburg as Stratolaunch’s new Vice President of Propulsion. Jeff joined Stratolaunch on May 22. I look forward to working with Jeff to explore new approaches to making access to space more convenient, reliable, and routine.

Jeff is an outstanding engineer and leader who brings a wealth of valuable experience to the team. Prior to joining Stratolaunch, Jeff was founder and President of Interstellar Technologies LLC, an engineering technology development and consulting company focused on technology development, advanced R&D, manufacturing, testing, production and operations for spacecraft, launch vehicles, and propulsion systems.

Prior to forming Interstellar, Jeff was the Senior Director of Propulsion Engineering at SpaceX in Hawthorne, CA, and served as the lead engineer and manager of methane engine systems including the Raptor engine development program.

Jeff was responsible for the development of the propulsion hardware and facilities used in next generation vehicles and propulsion systems capable of missions beyond Earth orbit, with an eye toward Mars.

Jeff also served as the Vice President of Propulsion Engineering at SpaceX overseeing flight, test, development and research operations while also supporting customer interactions, including those with NASA and the U.S. Air Force.

Jeff was also a lead propulsion engineer and turbomachinery technical project manager for the J-2X engine development program at the NASA Marshall Space Flight Center. Recently, the J-2X project has successfully tested both Engine 10001 and 10002, which utilized turbomachinery designed and built during Jeff’s tenure on the J-2X program.

Jeff also spent 4 years working for Aerojet as an engineering director for their liquid engine turbomachinery group and served as the site manager for the Aerojet-Woodland Hills engineering office in Woodland Hills, CA.

Jeff started his career in the U.S. Air Force as a flight commander and aircraft maintenance officer on KC-135R tanker aircraft at MacDill AFB, FL. He was selected to attend the Air Force Institute of Technology and earned his Master’s degree in Aeronautical Engineering.

Jeff was then stationed at Edwards AFB, CA, where he joined the liquid rocket engine branch at the Air Force Research Laboratory where he worked on several component and engine technology programs. His experience there included leadership of the joint Air Force-NASA Integrated Powerhead Demonstration engine. This program performed the world’s first hydrogen full-flow staged combustion cycle engine demonstration.

Since his first assignment to Edwards AFB, Jeff has been very fortunate to have built his career working on nearly all liquid engine technology development programs since the Space Shuttle Main Engine.

Jeff has received numerous Air Force and NASA awards including a NASA Space Flight Awareness award, the NASA Made It Happen award, the NASA Stennis Space Center Propulsion Test Director’s Leadership Award, and was an Air Force Research Laboratory Technical Program Manager of the Year.

In addition to his master’s degree, he has a Bachelor of Science in Aerospace Engineering from the University of Missouri-Rolla.

I’m proud of the progress the Stratolaunch team has made and I look forward to sharing our progress in the future. We’re excited to have Jeff join our team!

— Mr. Jean Floyd
Chief Executive Officer, Stratolaunch Systems Corporation

About Stratolaunch Systems Corporation

Stratolaunch Systems Corp., founded in 2011 by Paul G. Allen, is making great progress toward providing convenient, reliable, and routine access to low Earth orbit (LEO). We believe normalizing access to LEO has the potential to redefine how we collect rich and actionable data and drive advancements in science, research, and technology from space.


  • Ah, I remember Thornburg from the RD-180 hearings. He is a pretty cool guy, I wish him the best on his new post.

  • Terry Stetler

    It certainly sounds like they’re going the way VG did. I do wonder about cryo props stowed in the rocked or the Roc. Perhaps H2O2 and kero?

  • That would make a lot of sense. The fundamentals are much better for this than a path with solids.

  • Douglas Messier

    Hiring him would certainly allow them to do that. And he could do it the same way that Virgin Galactic built up its team: with a fair smattering of former SpaceX employees.

    This is one of the side effects of Elon’s start-up approach: people get a lot of experience quickly, but eventually burn out from the extreme hours and tire of having no life. So, they look for companies with better work-life balances. Elon ends up seeding other companies with talent.

    In any event, if they’re starting from scratch on a new booster, that’s a substantial commitment of money and time. Many years of work. So Pegasus XL, which starts launching in 2019 if the aircraft testing goes well, is likely a stop-gap measure.

  • JamesG

    Or maybe he can talk Elon into selling Stratolaunch some Raptor engines…

  • duheagle

    More like writing their intentions in the sky in flaming letters than a hint I’d say.

  • duheagle

    This Thornburg guy does get around.

    I think most of us always figured Pegasus was a placeholder for something much bigger and more capable to come.

    I eagerly await future developments.

    Paul Allen, I must say, does not do things by halves.

  • duheagle

    Doubtful. And even if he could pull it off he’d no longer qualify for the employee discount.

  • duheagle

    Agree. Given how long it might take Roc to go from wheels up to launch point, boil-off and replenishment could be serious problems. At a minimum, carrying extra prop to compensate would subtract from the maximum mass of launch vehicle and payload.

  • JamesG


  • JamesG

    Not to mention the added complexity, cost, and risk.

  • Mr Snarky Answer

    Not to mention endless crew loading arguments for commercial crew, this is far more dicey, and for no good reason.

  • JamesG

    Well… its not likely that they’ll be launching people with this contraption. If they do, they won’t be NASA, but private er…. “participants” who will sign off on that liability waiver.

    There will be considerable pucker factor for the Birdzilla’s flight crew however. So much so that Preparation-H and Metamusal will probably be standard issue.

  • Mr Snarky Answer

    Not on the rocket, on the airplane. Unless it is autonomous.

  • JamesG

    Considering the quantities of propellants and their explosive potential, they are pretty much the same. Along with everyone else within a half a km when she’s ready to go.

  • Mr Snarky Answer

    Yes rolling down the runway. What does a rejected takeoff look like? Break/tire fire with damn near EELV liquid booster slung next to it and a flight crew. What if you have to scrub? Landing back with that propellant load slung under…that could get really messy.

  • JamesG

    What is remarkable is that all of the people involved in this never said anything, they just took Mr. Allen’s money and smiled…

  • redneck

    Just like so many that take govt money. Take the Kings’ Shilling, carry the Kings’ pike.

  • Clio Marsden

    In the job description of a patron.

  • JamesG

    Also con artists.