> Seems like it would require, at minimum, several planets worth of raw material. You could mine it from asteroids, which have plenty of base metals. There's a

> Seems like it would require, at minimum, several planets worth of raw material. You could mine it from asteroids, which have plenty of base metals. There's already a speculative market for investors wishing to mine them. The only thing is; the technology for transporting it around doesn't exist yet. (We can land probes on them however for recon, but that's about it so far!).