No matter how you throw the dice, it all ways comes up snake eyes. In order for humans to exist in space we need all the things humans need to survive. Air, food, water protection against radiation, and gravity. In order to inhabit a ship large enough to produce gravity, we need really large spaceships, This mega ships can only be manufactured in the environment of space. That means we need to build shipyards to do R&D and build these future transport systems. We have shipyards on Earth; we need shipyards in space. Can we build the Arnold Schwarzenegger that would be super buffed to be future astronauts? Wow! A whole army of human terminators. It would like He-Man and the Masters of the Universe. It would be better than Roger Ramjet. I feel I am about to faint.