Les Johnson is a NASA physicist and author. By day, he serves as the Deputy Manager for the Advanced Concepts Office at the NASA George C. Marshall Space Flight Center in Huntsville, Alabama. 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. He is the author of novel Back to the Moon, coauthored with Travis S. Taylor, and the coeditor of the groundbreaking science/science fiction collection Going Interstellar.