In an alternate timeline in 1969, Soviet cosmonaut Alexei Leonov becomes the first human to land on the Moon. This outcome devastates morale at NASA, but also catalyzes an American effort to catch up. With the Soviet Union emphasizing diversity by including a woman in subsequent landings, the United States is forced to match pace, training women and minorities who were largely excluded from the initial decades of U.S. space exploration. Each subsequent season takes place ten years later, with season 2 taking place in the 1980s, season 3 taking place in the 1990s, (and as revealed in the season 3 finale) season 4 taking place in the 2000s.

Ronald D. Moore explained how history had been different in the series: "Sergei Korolev was the father of the Soviet space program; in our reality, he died during an operation in Moscow in the mid '60s. And after that point, their Moon program really never pulled together.... Our point of divergence was that Korolev lives, ... and he made their Moon landing happen."[8]

My snout descends