It did, until it didn't. Long story short: The Ark was a space station. It used to house hundreds of people, until we returned to earth. Lots of shit happened with grounders. Fighting, killing, people dying from radiation exposure. Eventually the inevitable priamfaya (basically a huge fire that engulfed the earth) came around and with the help of my friends I managed to launch a rocket back into space and dock at the Ark. We didn't have much in the way of food, so we survived off of algae and recycle urine. Appetizing, I know.