The Land Without a Sky

It's the late twenty-fifth century. After a cataclysm renders the Earth uninhabitable to people, humanity is once again a nomadic race, adrift in an interstellar desert in a ship nearly as long as Massachusetts is wide, harboring millions, with entire ecosystems living inside thanks to the artificial gravity.

With an impending crisis on their hands, the US government turns to a teenager they experimented on in utero.