Science Forums 2

[Moontanman]

I think it's important to dispel the urban legend of space travel being enormously expensive. The budget of the US space program from the very beginning to now is a very small percentage of the budget of the military. Even smaller compared to the entire GNP of the US. As for it being too expensive to bring refined metals to the earth from Jupiter's Lagrange points this is simply not true. By using various gravitational accelerations and such materials can be brought o earth orbit for very little energy expenditure. Much like using gravity assists to drive a space craft from the earth to Jupiter sending on back would take very little energy. Atmospheric braking can be used to bring such material to th surface of the earth. Moving stuff around the solar system is not an energy intensive endeavor. Bringing stuff from the surface of the earth to space is very energy intensive and will take controlled nuclear energy for it to be done realistically. Solar energy can be used to smelt metals from asteroids. Nuclear energy can also be used for this. In space nuclear energy really comes into it's own. The main problem will be establishing the infrastructure, once it is place anything is possible.