This seems to be a popularly held view. But I wonder what you think the last ~40 years of crewed spaceflight would have looked like if the shuttle had never been built?
Would the US still be using single-shot vehicles that are little more than incremental upgrades of 70s Apollo technology, as Soyuz basically is?
Or would some other reusable spacecraft have been built? If so, and given that the STS design was very much a product of the cold war era's military influence, would it have been much different? I dont think it would.
Among many things, the shuttle development produced the RS-25, which is the basis for the engines used on the SLS. So I'd argue that, from that alone, it wasn't a dead end.
As for the RS-25, it's used in the SLS mostly because NASA still has left-over engines from the Shuttle program in storage, otherwise it wouldn't make sense to use an engine designed for reusability on a single-use rocket. According to https://en.wikipedia.org/wiki/RS-25#Space_Launch_System, "Once the remaining RS-25Ds are exhausted, they are to be replaced with a cheaper, expendable version designated the RS-25E".
It would have been better than the road we took. Don't believe me? While NASA Administrator, Michael Griffin wrote in 2007 that the shuttle program had been a colossal mistake and that Apollo-Saturn-Skylab should have continued <http://aviationweek.typepad.com/space/2007/03/human_space_ex...>:
>Let’s assume that we had kept flying with the systems we had at the time, that we had continued to execute two manned Apollo lunar missions every year, as was done in 1971-72. This would have cost about $4.8 billion annually in Fiscal 2000 dollars.
>Further, let us assume that we had established a continuing program of space station activities in Earth orbit, built on the Apollo CSM, Saturn I-B, and Skylab systems. Four crew rotation launches per year, plus a new Skylab cluster every five years to augment or replace existing modules, would have cost about $1.5 billion/year. This entire program of six manned flights per year, two of them to the Moon, would have cost about $6.3 billion annually in Fiscal 2000 dollars. The average annual NASA budget in the 15 difficult years from 1974-88 was $10.5 billion; with 60% of it allocated to human spaceflight, there would have been sufficient funding to continue a stable program of lunar exploration as well as the development of Earth orbital infrastructure. I suggest that this would have been a better strategic alternative than the choices that were in fact made, almost 40 years ago.
SpaceX has finally done reusability the right way, but that does not mean that the shuttle was ever the right way.
I have no idea if anything linked to the US military could design a specialized device in the last ~40 years. But if you just took the bay out of the Shuttle, you'd get a much more reasonable design.
