Certainly straight out lies were told about the safety of the space shuttle. Or if they weren't lies then NASA was massively incompetant, which isn't a good thing either.

I think that improvements in technology will make it possible for people to go to mars before 2100 at relatively low cost and risk. However, rather than get into a discussion about future rates of technological development, if we simply assume a 3% economic growth rate, then in 75 years a mars mission would effectively cost about one eighth as much as it does now, which certainly could make it seem worth while.