Travis S. Taylor—“Doc” Taylor to his friends—has earned his soubriquet the hard way: He has a doctorate in optical science and engineering, a master's degree in physics, a master's degree in aerospace engineering, a master's degree in astronomy, and a bachelor's degree in electrical engineering. Dr. Taylor has worked on various programs for the Department of Defense and NASA for the past sixteen years. He's currently working on several advanced propulsion concepts, very large space telescopes, space-based beamed energy systems, and next generation space launch concepts. He has appeared in several episodes of the History Channel’s Universe series. He lives in , with his wife Karen and their daughter.
Les Johnson is a NASA physicist, manager, author, husband and father. By day, he serves as the Deputy Manager for the Advanced Concepts Office at the C. Marshall Space Flight Center in Huntsville, Alabama, one of the coolest jobs in the universe. In the early 2000s, he was NASA’s Manager for Interstellar Propulsion Research and later managed the In-Space Propulsion Technology Project. He was technical consultant for the movie Lost in Space and has appeared on the Discovery Channel series, “Physics of the Impossible” in the “How to Build a Starship” episode. He has also appeared in three episodes of the Science Channel series, Exodus Earth. In his spare time he writes popular science books and articles, including Solar Sails: A Novel approach to Interplanetary Travel, Living Off the Land in Space: Green Roads to the Cosmos and Paradise Regained: The Regreening of Earth.