text:  Four people volunteered to do that for the sake of science. NASA staged the experiment to see what it might be like to live on Mars. That mission is now over, and the crew completed their 378-day isolation, and one of them is with us to tell us what that was like. It's the mission's commander, Kelly Haston. So, Kelly, welcome back. Thank you so much. It's really wonderful to be back. And I say back as in to Earth, but you never left Earth, just in simulation.