As billionaires Jeff Bezos and Richard Branson lead the charge for a new commercial space race, we revisit an episode from our archives: What if women had been among the first to head to the moon? A NASA physician thought that wasn't such a far-fetched idea back in the 1960s. He developed the physical and psychological tests used to select NASA's first male astronauts. We'll investigate what happened to his program and what the women who were involved had to say. For more information about this episode, visit natgeo.com/overheard Want more? Private companies Virgin Galactic and Blue Origin are reaching the Earth’s edge. Find out what that means for the future of space tourism. Also, read more about why the ultrarich itch for space—and why scratching that itch helps keep crewed space exploration alive. Where is the edge of space anyway? The answer depends on who you ask. Also explore: Since the first humans went to space 60 years ago, we’ve learned a lot about what it takes to leave Earth. Here’s how the “right stuff” has changed since then. And for subscribers:
 See why some scientists think women are better suited to spaceflight than men. If you like what you hear and want to support more content like this, please consider a National Geographic subscription. Go to natgeo.com/exploremore to subscribe today. Learn more about your ad choices. Visit megaphone.fm/adchoices