This is a warning that I am looking at this thread and that it is AGAINST the community rules to talk about politics which this subject is intrinsically related. When Discussing SLS please stick to documented facts and verifiable, reliable sources. A couple of you have mentioned that it is a lot of politics, which it is, but PLEASE try to stay out of the nitty gritty and political parties. -------------------------------------------------------------------------------------- With that being said, It is taking forever because the real world is NOT like KSP. Just because an engine works one one rocket does not mean it will work on another without a lot of testing and redesign. A couple of issues that are running into, 1. Acoustics 2. the 5 segment SRBs (Space Shuttle was only 4 segment) 3. The tanks are much larger and require new tooling equipment to be built 4. the rocket is HUGE and in rockets mid size is easier to do than small or large 5. funding 6. goal uncertainty