“In fact, it is unclear whether NASA has the financing for any scenarios that do anything important beyond low-Earth orbit prior to 2020,” said Christopher F. Chyba, a Princeton professor of astrophysics and a panel member. “If we really want to do this, we have to provide a realistic budget for it. Otherwise, let’s be clear about the limits placed on us by the actual budget.”NASA has never been too good at living within a budget, or accepting the fact that there is not a strong mandate for the establishment of human colonies elsewhere in the solar system. After Apollo NASA tried to get get around budget and political realities, leading to the mess that it finds itself in today. The story is told in the following paper:
Pielke Jr., R. A., 1993: A Reappraisal of the Space Shuttle Program. Space Policy, May, 133-157.