The rare earth scarcity scare is already receding: https://www.theverge.com/2018/4/17/17246444/rare-earth-metals-discovery-japan-china-monopoly https://www.thev

The rare earth scarcity scare is already receding: https://www.theverge.com/2018/4/17/17246444/rare-earth-metals-discovery-japan-china-monopoly https://www.theverge.com/2018/4/17/17246444/rare-earth-metal... Yeah, heavy REMs are still expensive but there is really no reason to believe that they'll stay that way. New sites will be found, new extraction techniques will be tried and new processes developed and then the problem will go away. Sure, it could happen in space but it's so much easier to do here on earth that it might never be worth it to go to space for it.