"To look forward to the Moon, we need to learn from the past." //

The reality is that, even with a healthy budget increase, NASA can barely afford a human landing program on the Moon in the 2020s—at least using its Space Launch System rocket and usual ways of doing business, as it appears set on doing. This is more than enough for a space agency that has not flown a human into deep space for 47 years.

Talk of Mars is historically unsupportable with current budgets or NASA's existing technology. (As just one example, NASA at best can build one SLS rocket a year, and a single human mission to Mars would require six to eight SLS rocket launches). Past efforts to go to the Moon, Mars, or both have all ended in cancellation. So by talking about an all-of-the-above Moon-to-Mars exploration plan now, NASA's administration seems to be moving from the edge of the possible into the realm of the impossible