Earlier quoted context omitted.
I think that misremembers or misrepresents history. The DC-X was program developed in the early 1990s expressly to prove the feasibility of orbital rocket vertical landings and rapid turn-around/reuse. It never made it to the full orbital regime because it was scrapped early, but it was considered successful in proving the proof-of-concept. It was also managed by the predecessors of ULA (McDonnel Douglas, which later…
https://x.com/thesheetztweetz/status/1251155738421899273 Tory Bruno saying "no one has come anywhere near close to demonstrating these economic sustainability goals". https://www.teslarati.com/spacex-critic-ula-ceo-reusable-roc... > “We have not really changed our assessment over the last couple of years because we have yet to see the other forms of reusability—flyback or propulsive return to Earth—demonstrate econom…
The technological viability was shown with the proof of concept. If you meant strictly economic viability was unknown, I agree with you. This isn't meant to disparage SpaceX. They're doing great. I would say there is a risk that isn't often talked about which is the quality risk. Early on, SpaceX disregarded well-known quality control checks, presumably because they didn't think they were worth the time/cost. When that burned them, they integrated those checks. Do that enough times, the economic viability erodes.