Science Forums 2

[CraigD]

Assume for a moment that Earth-space elevators are not achievable for the next several centuries. Despite a lot of optimistic enthusiasms for them, the engineering challenges are truly daunting, and may prove practically insurmountable.

All that is really necessary for the colonization of the solar system is the creation of habitats capable of sustaining large numbers of human beings, and a launch capability comparable to our current. Once an artificial “ecological nitch” for human beings exists, humans can do there what they have historically proven to do best – reproduce exponentially. With current artificial fertilization and implantation technology, and launches of one or a few small payloads of sperm and ova, problems of viable breeding population size can be circumvented.

What’s critical for the creation of livable extraterrestrial environments is large amounts of energy. Assuming that launch capability prohibits supplying extraterrestrial colonies with fissionables (eg: uranium, plutonium), that generating useful energy with artificial nuclear fusion remains beyond human capability for several centuries, and that fuel is difficult to obtain outside of earth, this leaves 2 obvious feasible sources for large amounts of energy: solar radiation, and planetary magnetic induction.

These 2 energy sources reveal 2 “sweet spots” for colonization: inward, toward the sun, where solar radiation is most intense, and the vicinities of giant planets, expecially Jupiter, where the mechanical energy of the orbit of great and lesser moons is most easily obtainable through magnetic induction with the planet’s strong moving magnetic field.

Mars and the asteroids are not within these sweet spots. So, while the asteroids may provide valuable, energy-efficient access to material resources, I suspect Mars is of limited value for colonization in the next few centuries, compared to the greater and lesser moons of Jupiter, or the empty space near the Sun.

I’m optimistic that, even if dramatic improvements in Earth launch capabilities, such as space elevators, or dramatic improvements in compact power generators, such as controlled fusion, fail to be realized anytime soon, space colonization is still possible, by virtue of sheer human fecundity.