The US needs to create a heavy lift variant of the commercial orbital transportation services contract (COTS) [1] and/or the Commercial Crew Development program (CCDev) [2] and scrap the SLS program or at least release it from it's stupid congressional requirement to use grandfathered space shuttle contractors.
Estimates for the true cost of each space shuttle launch, which NASA and Congress were always cagey about, range from 700 million to over one billion dollars ( $196B/133 flights [3] ). The cost of the entire COTS program that created "two new U.S. medium-class launch vehicles and two automated cargo spacecraft"[4] as a replacement for the shuttle's cargo services was $800 million, less than or equal to the cost of a single shuttle flight.
In light of that it's always frustrating that I see the US dinking around with the $10+ billion dollar Orion program [5] or talk about throwing good money after bad by adding astronauts to the EM-1 mission. I mean, come on! How tied to corporate kickback interests and tiny amounts of local jobs can you get? Can Congress really not see the big picture here and the idea that we could have more people and mass in space (and probably job on the ground too) for a fraction of the current program costs?
[1] https://www.nasa.gov/commercial-orbital-transportation-servi...
[2] https://www.nasa.gov/content/commercial-crew-program-the-ess...
[3] https://en.wikipedia.org/wiki/Space_Shuttle_program
[4] https://www.nasa.gov/content/nasa-releases-cots-final-report