- Source for Vulcan total program cost? All I can find is their per-launch pricing. Tory Bruno himself apparently said that "new rockets typically cost US$2 bil

- Source for Vulcan total program cost? All I can find is their per-launch pricing. Tory Bruno himself apparently said that "new rockets typically cost US$2 billion, including US$1 billion for the main engine." - Not sure where you're getting the SLS number, the GAO report at https://www.gao.gov/assets/gao-23-105609.pdf https://www.gao.gov/assets/gao-23-105609.pdf claims, "Since 2011, NASA has spent $11.8 billion to develop the initial SLS capability." - I think the marginal cost is a fair question. The whole party line out of NASA was that this time Moon exploration would be sustainable. If each trip costs > $1B before you even put a payload on the rocket that's a big problem.