Rocketing into the new millennium in the eight years since Season 3, 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.

Season 2 picks up a decade later in 1983. It's the height of the Cold War and tensions between the United States and the USSR are at their peak. Ronald Reagan is President and the greater ambitions of science and space exploration are at threat of being squandered as the US and Soviets go head to head to control sites rich in resources on the moon. The Department of Defense has moved into Mission Control, and the militarization of NASA becomes central to several characters' stories: some fight it, some use it as an opportunity to advance their own interests, and some find themselves at the height of a conflict that may lead to nuclear war.