aye we could have. and they'd all be long dead on the surface of Mars by this point. getting them there isn't enough.

Keeping them alive and returning them doesn't require "a leap" which is the central point of OP I am disagreeing with. We have all the technology, material science etc to do it.

Sure, it requires some research, engineering and a crapload of investment, but it doesn't require anything that is currently "science fiction".