And as for “living off the land” on Mars, what started the space colonization movement of the 70’s was the singular conclusion that one gravity was a prerequisite to any permanent colony. The less gravity the easier it is to build centrifugal “sleep train” facilities for small crews on small icy moons but for large populations miles in diameter artificial spinning hollow moons constructed of lunar material has always been, and will remain, the best plan.
It goes without saying (but I will say it anyway) that such a public works mega-project is the anti-thesis of the NewSpace scam (retire on Mars!) presently being endlessly hyped to the public.”
I responded to someone who had posted some interesting artificial gravity numbers on a forum. Unfortunately I cannot post those figures here because the moderator of that site has repeatedly banned me and warned me about using any material posted on his blog- or rather, news site, since he does not like it to be called a blog.
To generate one gravity on the inner surface of a sphere about 6000 feet in diameter the sphere would spin a little over 200 miles per hour and complete one revolution in a minute or so. A person living in such a sphere would take about an hour to walk the circumference and arrive back at the starting point.
It is a good example to explain what a Bernal Sphere would be like.
“In 1966 Gemini 11 did a tether-generated artificial gravity experiment. A several thousand foot long tether system with equal masses on either end generating one gravity is the solution that people have been doing calculations for since the 1930’s (it was not known if humans would remain conscious without gravity so the tether was a solution to this possibility even then). No extensive testing is needed. We just need to build it and use it as it is pretty straightforward.
The ice on the Moon is the source for shielding. 15 feet and several hundreds tons of water for a small capsule. Well over a thousand tons for the very minimal crew space needed on a long duration mission. This is also pretty straightforward as well as how to push such a shield around the solar system- there is only one practical system. All the work to conclusively prove this concept was done in the 60’s and includes over 1000 live tests of the required devices.