>>1474736>"They" -- NASA or Congress?NASA. The only reason you would ever go to the trouble of designing and building a reusable launch vehicle is if operating costs would make it cheaper than using expendables. In that case, expendable rocket manufacturers would either exit the launch industry or build their own reusable vehicles because all their customers would switch to the STS. Outside of that, if the shuttle flew more missions, each mission would be cheaper and the overall cost savings from not using expendables would be higher, thus NASA and DOD originally planned to fly all possible payloads on the shuttle. 24 missions a year was the minimum baseline for most of the projects NASA and DOD's studies looked at. They literally shut down the Atlas/Titan/Delta production lines due to the shuttle.
