Years ago, talk of a space race referred to competition between the United States and Soviet Union to put men in orbit and then send them to the moon. Nowadays, it applies to a few billionaires vying to go where only the most powerful nations went before—that is, beyond planet Earth. Christian Davenport, a journalist on the Washington Post’s financial staff who covers the space and defense industries, was able to talk to these billionaire entrepreneurs and chronicles their rivalries and ambitious, out-of-this-world projects in The Space Barons. These private, commercial space efforts are only about a decade-and-a-half old or less, yet they’ve made tremendous strides in a relatively short time, marking the end of the government’s monopoly on exploring the cosmos and holding considerable promise for the future.