An expert assesses the submersible rescue effort

A huge search is underway for five people on a missing sub, which is running dangerously low on oxygen. Searchers have picked up the sound of banging underwater, which has given rescue teams hope of finding the submersible. But time is critical as officials think they have less than a day of oxygen left. Colonel Terry Virts is a veteran NASA astronaut, retired colonel in the US Air Force and also close friends with Hamish Harding, who is on the sub. He joins Bianna to talk about the search and rescue operation.  Also on today's show: Vladimir Ashurkov, Russian dissident/Executive Director, Anti-Corruption Foundation; Special Olympics Chairman Timothy Shriver; journalist Linda Villarosa  To learn more about how CNN protects listener privacy, visit cnn.com/privacy Learn more about your ad choices. Visit podcastchoices.com/adchoices