As a retired physical scientist with the U.S. Bureau of Mines and a long-ago mining industry exploration geologist, I was appalled by the false impressions presented in the May 8 letter “Assessing mining in space” and the April 30 Business article “Space mining may be a decade away. Really.” Mining as suggested in the text would entail the discovery of valuable minerals that simply would be loaded onto a spaceship for delivery to markets on our planet or to some orbiting planetary workshop — and before work begins, please do remember to file a mining claim with the proper authorities. The digital world of space mining shown in the movies is not practical. Billions of dollars’ worth of platinum from a captured asteroid? Gimme a break!

An astronaut miner would not simply step outsidie of his sealed capsule and load up the cargo hold with bars of platinum or gold or zinc or copper or rare-earth metals. These elements generally occur, combined physically or chemically, as a tiny, tiny, tiny fraction of heavy, bulky, relatively worthless but intimately associated rock material known as gangue. Separating the valuable elements from the gangue requires mining, crushing and grinding and concentration using heavy, robust, energy-gobbling machinery plus considerable water and/or exotic chemicals that may or may not perform safely or efficiently in outer space. Refining requires more of the same. And, of course, in today’s regulated environment, the resultant worthless waste or tailings and spent chemicals must be properly disposed of and the impacted surface of the asteroid must be reclaimed and inspected for compliance by some bureaucracy.

In the meantime, domestic at-hand onshore and offshore hard minerals and fuels are increasingly being locked up for political reasons while our dangerous import reliance on foreign sources expands.

John Lucas, Vienna