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.

After a sudden crisis, the Martian crews pull together.

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