Author Claude Lafleur took NASA's reported expenditures, converted them to 2010 dollars, and made a colorful graph. Such graphs beg for discussion, which you can see on The Space Review. I didn't try to digest his more detailed page that breaks down how he got his figures. Budget analysis is a bit like statistics - "There are three kinds of lies: lies, damned lies, and statistics." (Mark Twain). Nevertheless, his analysis is quite interesting. A couple of the more interesting tidbits:
- The cost per Apollo mission, in 2010 dollars is 18B!
- Even though its total cost is about twice that of Apollo, the cost per Shuttle mission is a paltry $1.4B. (He includes the Shuttle's ISS mission in the cost analysis of the latter, but still...)
- The cost per crewman-day on Skylab was 5.5M.
- The cost of a crewman-day on ISS is 7.5M (including the required Shuttle flights and contributions from all partners.)
- Looking at current budget plans, Exploration programs, despite the cancellation of Constellation, will be funded at $4B/yr through 2015. That's more than ISS.