When people think of the inevitable spread of humanity to space and the colonization of it, they tend to think of people living on the Moon and Mars.
The problem with colonizing the various moons and planets is that they are huge gravity holes. We are having far too much trouble climbing out of Earth’s gravity hole in order to go and fall into other holes and set-back our achievement. Not only that, we are limited to the native gravity of the moon or planet. The moon only has a gravity of 0.16 gees. Mars only has a gravity of .38 gee. Our bodies do not fare well in a micro-gravity environment and tend to suffer health problems and bone loss. It is likely they will do poorly on the Moon and Mars.
Fortunately, we can generate full 1 gee gravity with asteroids. The trick is to spin the asteroid and then live inside it, the outward centripetal force can substitute for gravity. As it turns out, larger asteroids don’t have to be spun as fast to generate the an artificial gravity of 1 gee. The rotation rate affects the dizziness and the body’s health, 2.5 RPM is the recommended maximum and 1 RPM or less is considered ideal. This translates into asteroids that are at minimum 140 meters in radius and ideally bigger than 890 meters in radius.
Another advantage of asteroids is there are asteroids that come closer to the earth and have a lower delta-v than getting to the moon or mars. The delta-v determines the energy cost required to get there. In fact, some asteroids come near the earth and then swing back out to the asteroid belt. Wouldn’t that be a great way to colonize the asteroid belt? Jump on a NEA (Near Earth Asteroid), and ride it out to the belt and hop off and colonize all those asteroids?
The microgravity environment and the resources of the asteroid belt are huge pluses for industry. Microgravity would be useful in so many ways, in terms of shuttling resources around, and for science and technology processes. Mining would likely be a very low energy endeavor once established and the various metals will be quite easy to extract.
The ease of getting to asteroids, the ability to generate necessary gravity from spinning, the ability to ride the asteroid out to the asteroid belt, the greater accessibility of resources and access to microgravity environment makes asteroid colonization a clear winner. Lets forget about colonizing anything else. Sure, it is romantic to colonize the moon or mars, but it is a waste of resources when we can achieve much greater freedom and capabilities with asteroids.
