Over a week ago, Europe’s ArianeGroup unveiled a new reusable launch vehicle they call “SUSIE,” a “Smart Upper Stage for Innovative Exploration.” Given the acronym, NASA must be rubbing off on them. Though the name is sure to be memorable, like Wall-E, reusable launcher announcements usually make a splash only to be quickly forgotten. But this is not just another startup putting out a press release that trends on Twitter while also saying they are in stealth mode. This is ArianeGroup, presenting at the International Astronautical Congress in Paris. This is when some (like me) in the space community say, “you had me at reuse.”

Yet the details of SUSIE’s funding should give us pause, and the bigger picture leaves curious questions. First, funding is unclear. You’ll find the European Commission “Horizon Europe” program and €95.5 billion, which then, like Genesis, leads to a lot of begets. Horizon Europe begets space research, which begets more programs and acronyms, which begets reusability research, which begets some low 10s of millions of Euros for SUSIE. For anyone familiar with NASA’s reusable launch projects, there is a little Deja-vu. An extensive portfolio begets this, then that, and many layers of the onion down, you find the relatively small projects where the rubber hits the road. In other words, SUSIE appears to be what we in NASA called study money.
Reusable launch investments are the bookends of my time in NASA’s advanced projects.
While there is little funding, there is an immense technical challenge. SUSIE tackles the hardest part of reusability, bringing back the part of the rocket that goes all the way to orbit. A history of investments here could fill a book, starting with a Shuttle that put Orbiters the size of 737s in orbit and, near the end, delving into the SpaceX Falcon 9. SpaceX threw its design into reverse, making the first stage reusable, not the last as with Shuttle.
Reusable launch investments are the bookends of my time in NASA’s advanced projects. In X-33, circa the late 1990s, I played an insignificant role, asked a few times to provide an operational perspective. This was among the first advanced projects I was involved in, my full-time day job being over in the Shuttle program. A perk was my crawling around the X-33 structure once as it was taking shape. Lockheed would build liquid oxygen and hydrogen tanks, a launch facility, and a laundry list of parts and pieces.
Decades later, at the end of my career, I was heavily involved in the DARPA XSP program, one more charge at a reusable launch system. This program, too, built a liquid oxygen tank and another long list of parts and pieces, but with the launch pad and equipment left on the drawing board.

Each of these programs met an early demise. As the X-33 ran into trouble, hydrogen tanks bursting counting as a bad day, Lockheed would find NASA ill inclined to provide more funding. Eventually, NASA canceled the X-33 program in 2001. Eerily similar, the DARPA XSP ran into trouble, this time with Boeing as a partner. Here, DARPA reminded Boeing this was a firm-fixed-price contract. Regardless of the scolding, Boeing opted to bow out of the partnership this time. One project was “canceled” by NASA, and the other “terminated” by the partner, Boeing. In theory, these are two very different beasts, canceling vs. termination. In practice, not so much. History repeated, the only difference being the time travelers were aware of the loop.
Perhaps one day, we will look back and wonder what all the fuss was about…
Design decisions in this space are, stating the obvious, complex. Yes, this is rocket science. SpaceX took an arguably successful design route, deciding that a reusable first stage or “booster” offered the most outstanding value. A pound of additional weight on a first stage does not mean a pound of payload lost. If you have too many miscalculations, too much optimism, or both, you have a good chance you might not stray too far from the payload you targeted. That final payload is also the market you want to serve and the promise you made to investors. The less that payload capability changes, and totally disappearing is possible, the better.
SUSIE will have the opposite problems, though these are not unsurmountable. As occurs for SpaceX with its Starship, being a pound off here or there on an orbital stage means a pound less useful payload delivered to orbit. These are complex challenges, but full reusability for sustainable, affordable systems must overcome these, eventually. The alternative is throwing away expensive hardware, the costs of which no aerospace manufacturing seen to date would seem to get around. Better sooner than later, with a full disclosure for the land mines ahead.
SUSIE and studies like it may at least make a small dent in a significant problem, as NASA did over the years. Perhaps one day, we will look back and wonder what all the fuss was about calculating a pound here or there or the technology we wrapped it in. Some studies here, some success there, a Starship, a SUSIE, or a Stokes, and before you know it, you might have full reuse.