Something crossed my mind
Nixon approved the space shuttle in 72 and it was operational in 81, 9 years later
SLS was announced in 2011 and it's 2020, 9 years later and no fucking rocket
The space shuttle was a revolutionary and complex vehicle, it was nothing like the articles it replaced.
SLS is literally a dumbed-down space shuttle design with the shuttle part removed. Everything else is established science from 1981