> As far as I'm concerned I wish this had started 40 years ago rather than a bit less than 20 Absolutely agree. I bought an 8-pack of used Heinlein paperbacks

> As far as I'm concerned I wish this had started 40 years ago rather than a bit less than 20 Absolutely agree. I bought an 8-pack of used Heinlein paperbacks the other day that I hadn't read since I was a wee lad, which included 'The Rolling Stones' -- a slim volume about a family that live in comfort on the moon, but who get the itch and buy a used spaceship and head off for more exciting parts of the Solar System. In a paragraph or two it explained gravity well maneuvers and other Kepler-ish things better than current YouTube subject matter experts. It also described, in a sentence or two, that the starships had 3-way voting computer systems, where 3 computers get the same sensor inputs and 2 of them can overrule the 3rd in the case one differs. To the author, these were basic things that would clearly exist, because of physics. Sure, it missed some marks -- underestimated the computer, for one; its heroes were still manually 'astrogating' and doing a lot of difficult math to plot their courses, when now we know they could have just played Kerbal Space program ;) -- though I thoroughly enjoyed seeing a reference to them handing their flight plans to a 'programmer' who filed them into a big computer system. Of course, it was imagining a world where we would found a moon base in the 1980's. But I appreciated the solidity of its underlying premise: that a robust human presence in space was inevitable, because the difficulties that space flight presents, especially once you climb out of Earth's gravity well, are just not that far out of reach. That spirit was alive and well when that book was published ... ... in June of 1952. It turns out that, given human nature, we needed a lot of advances in computing to overcome difficulties, some engineering but others that no one could have foreseen -- like the fact that radioactive rockets and the additional power they could bring to the table were effectively off-limits on earth for human and political reasons, or that geopolitical and business reasons would concentrate space investment in areas that could be considered inefficient if conquering Earth's gravity well is your aim. But they weren't off by that much. The physics that stared them in the face continue to stare us in the face, and declare: this is doable, folks. There's no reason humans can't live and work in space on a large scale. We need some vehicles built, but some of them are getting built right now ...