NASA's Alan Stern talks Pluto ... and beyond

There were some tense hours at the operation center for the New Horizons mission when the spacecraft briefly lost contact with Earth on July 4, 2015, just days from its long-awaited flyby of Pluto. It's just one of many gripping moments in a book that Alan Stern, the mission leader and a co-author of "Chasing New Horizons" along with astrobiologist David Grinspoon, describes as a "techno-thriller about how the farthest planet was explored." Dr. Stern recently sat down for an interview in his Boulder, Colo., office, surrounded by photos and mementos from the New Horizons mission – a mission that took decades to convince NASA to get off the ground and another decade to travel 3 billion miles to the last unexplored planet in our solar system. The New Horizons spacecraft continues to explore the vast reaches of the Kuiper Belt, at the outer edge of our solar system. His responses have been edited for clarity and brevity.