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.

The astronauts move quickly to build Martian bases.

A joint mission brings about conflict between crew members.

Plans to leave Mars are complicated by an unforeseen issue.

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