A year and a half ago, I wrote an article very critical of the Space Launch System (see “The SLS: too expensive for exploration?”, The Space Review, November 28, 2011). To see if this assessment should now be updated, I checked a series of sources and found that little in the situation has changed, with no reliable cost estimates of an SLS launch yet available anywhere. It is actually amazing how hard it is to get cost estimates for any part of the SLS/Orion system. Another assessment corroborates this problem. While I was working on this article, two startling pieces of information came to light.
It is hard to see how a large rocket like the SLS, which is, with all of its components, destroyed in the course of a launch, could possibly cost a lot less than the Space Shuttle on a per-launch basis. It will probably cost considerably more, since all of the expensive rocket engines and other equipment will either smash into the ocean at high speed or reenter the atmosphere and burn up.