New breakthroughs might mean interstellar space travel will soon be more than just science fiction. Les Johnson is a physicist and principal investigator for NASA’s first interplanetary solar sail space mission, Near-Earth Asteroid Scout and Solar Cruiser. He joins host Krys Boyd to discuss space propulsion and robotics, goals for reaching exoplanets and lessons in physics, all with the aim of traveling to the great unknown. His book is “A Traveler’s Guide to the Stars.”