> the overall capabilities and prospects of mankind remain substantially the same I disagree. Advancement is directly related to how many minds we can free up

> the overall capabilities and prospects of mankind remain substantially the same I disagree. Advancement is directly related to how many minds we can free up to work on intellectual pursuits. Even before Moore's law, publications and rate of invention largely tracked with size of population (minus the portion preoccupied with agriculture). Going to Mars involves calibrating some rockets and making a sustainable habitat for long periods of time. Hard problems, to be sure, but there's nothing about that trip we would do without thoroughly testing it first on Earth. We mostly know how to send projectiles throughout the solar system, and we mostly know that long term stays in space suck, and we mostly know that robots and telescopes pay back orders of magnitude more in scientific discoveries than equivalent manned missions for the cost. (ie, manned missions have the mirrors on the moon and tang, hubble and curiosity have contributed far more to space science...)