@Zron @technology True, #NASA was forced to use the Shuttle engines but part of the reason was the US had no capability to design and manufacture a similar rocket motor. We were entirely dependent on using the Russian Proton engines. This was one factor in support for helping SpaceX — to recreate a U.S. capability to build rocket motors. At the time, we needed a new launch system engine for smaller uncrewed spacecraft missions. That decision had nothing to do with the Lunar/Mars human spaceflight ambitions. The alternative proposal on the table was to refurbish stored ICBMs for this purpose. The Earth-to-Orbit ISS resupply need came later. (I know this because I was there and involved.)

True, NASA is basically a jobs program — for the southern states; this is where most of the money goes. LBJ did that to get the votes for the appropriations needed and to keep the southern state Democrats in the party. Part of the political culture at NASA HQ is to “efficiently distribute money to Congressional districts.” The NASA centers in Houston and Huntsville had a corresponding sense of entitlement, at least when I was working with them at the beginning of the Constellation program. Now that Senator Shelby (Alabama) is no longer the ranking head of the Senate Appropriations Committee, maybe things will start to change in the human spaceflight area. Huntsville’s NASA centers had/have responsibility for the remaining space shuttle’s engines.