[fsloth]

I'm not from USA, but my limited understanding is that the contractors (Boeing etc) work for Nasa, which in turn is guided by congress. And congress does not specify engineering or scientific goals, but how much government funds they want directed to their district. Hence it's broken from the start as a vehicle for engineering progress, but successful if the measure of success is to create jobs and subsidies.

[wolf550e]

Congress mandates specific technical details to force contractor choice and factory location in right district. For example RAC 2 (Saturn V reboot) won the NASA engineering trade off but congress mandated RAC 1 (shuttle tank, engines and boosters but without orbiter) becomes "SLS", to give jobs to shuttle contractors in their districts. See https://www.youtube.com/watch?v=ZNZx208bw0g