Robots are making progress on space exploration, along with billionaires

High profile trips by billionaires Richard Branson and Jeff Bezos have more people thinking about the future of space tourism. There's a long way to go before that's common, but one destination for would-be space explorers is Mars. And right now, NASA scientists are working on robots to help explore more of the planet first. Ali Agha, a principal investigator and research technologist at NASA's Jet Propulsion Laboratory, is testing a fleet of robots, including the Boston Dynamics one known as Spot, by sending them into caves in Northern California. The following is an edited transcript of our conversation.