It’s been 60 years, to the day, since Soviet cosmonaut Yuri Gagarin was the first human to travel to space in a tiny capsule attached to an R-7 ballistic missile, a powerful rocket originally designed to carry a three- to five-megaton nuclear warhead. In this new episode marking the 60th anniversary of this historic space flight—the first of its kind—Scientific American talks to Stephen Walker, an award-winning filmmaker, director and book author, about the daring launch that changed the course of human history and charted a map to the skies and beyond.

Walker discusses his new book Beyond: The Astonishing Story of the First Human to Leave Our Planet and Journey into Space, out today, and how Gagarin’s journey—an enormous mission that was fraught with danger and planned in complete secrecy—happened on the heels of a cold war between the U.S. and the Soviet Union and sparked a relentless space race between a rising superpower and an ailing one, respectively.

Walker, whose films have won an Emmy and a BAFTA, revisits the complex politics and pioneering science of this era from a fresh perspective. He talks about his hunt for eyewitnesses, decades after the event; how he uncovered never-before-seen footage of the space mission; and, most importantly, how he still managed to put the human story at the heart of a tale at the intersection of political rivalry, cutting-edge technology, and humankind’s ambition to conquer space and explore new frontiers.