Watch For All Mankind Season 4 Online Free. Rocketing into the new millennium in the eight years since season three, Happy Valley has rapidly expanded its footprint on Mars by turning former foes into partners. Now 2003, the focus of the space program has turned to the capture and mining of extremely valuable, mineral-rich asteroids that could change the future of both Earth and Mars. But simmering tensions between the residents of the now-sprawling international base threaten to undo everything they are working towards.