Is there life on Mars? NASA's Perseverance rover set for nail-biting landing

Seven months after its departure from Earth, NASA's latest Mars rover is just hours away from its destination. We speak to former NASA astronaut Garrett Reisman about the perils of trying to land on the red planet, how exactly the samples that Perseverance collects are supposed to get back to Earth, and whether he'll be signing up for future manned missions to Mars.