Les Johnson is a scientist, an author, and the Senior Technical Adviser for NASA’s Advanced Concepts Office at the Marshall Space Flight Center. When he’s not designing spaceships, he’s writing science fiction or popular science books. “Rescue Mode” and “Back to the Moon” are among his science fiction novels from Baen Books. “Harvesting Space for a Greener Earth” is his latest popular science book in which he describes how space technology can help solve environment problems on Earth. Learn more about him at www.lesjohnsonauthor.com.