Don’t ask SpaceX for projections, reach for the stars Opinion Elon Musk can’t provide concrete figures showing how much money SpaceX will make from space tourism or asteroid mining because his horizons are lightyears away, says Rainer Zitelmann In 1949, 20 years before the first moon landing, the world-famous American science fiction author Robert A. Heinlein wrote the short story The Man Who Sold the [...]