>>12013701I used to be a lead engineer working on SLS so I can give you my insights.
Generally, the customer (NASA) can't get out of their own way. They don't like the idea that they're not in control of building it, so they want excessive insight into every aspect, and they demand extreme and unnecessary analysis. Coupled with the fact that even now they are still changing the design and mission profile causes costs and schedule to balloon.
Other than that, core stage is completely fucked up. I never had a lot of insight into that part, but Boeing seemed to have numerous problems mostly springing from carelessness and overconfidence.
Service module had problems as well, but that's a European thing so I had even less insight there.
Orion had its own set of problems and was only slightly ahead of core stage, but that got swallowed up by Boeing's problems.
