NASA is in crisis as the Soviets land the first man on the moon in 1969, the beginning of an alternate history.

Director von Braun opposes President Nixon's directive, with dire consequences.

A training accident spurs a national debate about women astronauts.

Ed and the crew change Apollo 15's landing site after lunar ice is detected.

A launchpad accident leads to delayed missions and FBI background checks.

NASA preps a Jamestown relief mission, while Karen waits for news at the hospital.

A crisis in space puts the Apollo 24 and 25 crews in peril.

Ed handles a trespasser. Ellen and Deke chart a new course without Mission Control.

Nearly a decade later, technology and lunar exploration have taken huge strides—but a solar storm threatens the astronauts on Jamestown.

Ed's reckless behavior at NASA shakes the foundation of the Baldwin family. Tracy attempts to readapt to life in space.

American astronauts and NASA leadership prepare for a new mission with unlikely partners. Ellen gets in touch with an old friend.

Ellen is challenged by her new role. Margo’s allegiances are put to the test. Karen explores new opportunities—personally and professionally.

Gordo returns to space. Molly faces an upsetting new reality. Aleida confronts her first major hurdle at work.

The rivalry between American astronauts and Soviet cosmonauts intensifies as last-minute changes impact the Pathfinder mission plan.

Tensions between the U.S. and the Soviet Union reach an all-time high on the moon, throwing multiple missions into jeopardy.

Nearly 10 years have passed. Danielle and Ed attend a celebration, where things take a terrifying turn.

A commercial spaceflight company makes an announcement. The choice over who'll command the Mars mission leads to a shift in personnel.

As NASA scrambles to prepare for the launch to Mars, Margo is confronted with a harsh personal reality.

A surprise maneuver during the journey to Mars provokes desperate measures.

The race to land first on Mars brings together unexpected allies.

After a sudden crisis, the Martian crews pull together.

Plans to leave Mars are complicated by an unforeseen issue.

The Martian crew debates how to save the life of one of their own.

Miles tries to make ends meet. Margo finds herself pulled into a dangerous situation.