asteroid mining
There are three major technological challenges to asteroid mining (1. getting to an asteroid, 2. bringing the asteroid back to earth, and 3. extracting the materials).
The costs for a successful asteroid mining mission are generally estimated to be in the $20-billion to $40-billion range, a trivial amount compared to the current U.S. military budget. And the ores from just one well-chosen asteroid will pay for the entire mission and make enough additional profit to fully fund the many other activities of a space force.
Rare-earth e;ements are rare at the surface of the earth, but will be common in a well-chosen asteroid. These elements include cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium (Tm), ytterbium (Yb), and yttrium (Y).
Rare-earth minerals are difficult to economically exploit on earth, but will be common in a well-chosen asteroid. These minerals include aeschynite, alianite, apatite, bastnäsite, britholite, brockite, cerite, floucerite, flourite, gadolinite, monazite, parisite, stilwellite, synchysite, titanite, wakefieldite, xenotime, and zircon.
Rare-earth magnets are difficult to economically exploit on earth, but will be common in a well-chosen asteroid. The two types of rare-earth magnets are neodymium magnets and samarium-cobalt magnets.
Isaac Arthur’s Asteroid Mining:
