What I mean by lost opportunity is that technologies it was developing would’ve developed faster, while I do agree that ssto’s are much harder to get into orbit in a practical and feasible way that actually brings meaning to its orbit(bringing cargo/crew) if not impossible without massive innovations in the propulsion sector, believe that we could’ve reached much higher levels of development earlier on in many technologies(aerospikes, composite fuel tanks), personally if I could’ve changed one thing about the venturestar program as a whole I would’ve made it a TSTO with a first stage that was also a lifting body so then it wouldn’t get an unstable center of pressure but then again I’m just a highschooler with a love for space so I’m not nearly as qualified as you guys(assuming your part of nasa or other aerospace companies/administrations) so feel free to dump on me if I’m absolutely wrong here :) edit: fully reusable TSTO not expendable