There are a lot of reasons for not doing something. And if humanity had come up with all the reasons for not doing something we wouldn't have spread across the Earth the way we have. There's a curiosity, and I would submit that that curiosity will put human beings on the surface of Mars.

No dream is too high for those with their eyes in the sky!

Heavy lifting doesn't need to be heavy spending if we do the job right.

What are you going to do with astronauts who first reach the surface of Mars and then turn around and rocket back home-ward? What are they going to do, write their memoirs? Would they go again? Having them repeat the voyage, in my view, is dim-witted. Why don't they stay there on Mars?

The way I see it, commercial interests should manage a lunar base while NASA gets on with the really important task of flying to Mars.

Once you've been first, it cannot be done again. Not by you, not by anyone else.

One of the major problems with long-term deep space human flight is the requirement for radiation shielding.