When NASA sent astronauts to the moon in the 1960s and 1970s, the agency excluded women from the corps, arguing that only military test pilots --- a group then made up exclusively of men --- had the right stuff. Eventually, though, NASA recognized its blunder and opened the application process to a wider array of hopefuls, regardless of race or gender. From a candidate pool of 8,000, six elite women were selected in 1978: Sally Ride, Judy Resnik, Anna Fisher, Kathy Sullivan, Shannon Lucid and Rhea Seddon. In THE SIX, acclaimed journalist Loren Grush shows these brilliant and courageous women enduring claustrophobic --- and sometimes deeply sexist --- media attention, undergoing rigorous survival training, and preparing for years to take multi-million-dollar payloads into orbit.