In 1978, NASA recruited six candidates out of thousands of applicants for a special, groundbreaking mission: to become the first American women in space. Over the next few years, the six women would endure sexism, grueling training, and unending scrutiny from the media. In her new book, "The Six: The Untold Story of America's First Women Astronauts," author Loren Grush explores the stories of these female pioneers, along with the longer history of women's fight for inclusion in the male-dominated world of NASA.On this episode, we talk with Grush about how America's first female astronauts came to be, their journeys and challenges, and what kept them committed to their mission. Later, we hear from another space pioneer — a Navajo NASA engineer who says his childhood in Arizona prepared him for his work studying Mars.