Humans on both Earth and Mars try to make sense of cataclysmic events that have occurred in Planum Australe.
Crews split apart and take different directions, which could have tragic consequences.
Rachel makes a last ditch effort to change Commander Li’s mind, while Sam and Paul work on a plan that could change everything.
As work resumes and Earth’s refugees get closer to launching for Mars, concerns and debates arise over the new comet-intercept mission.
Sam tries to fight against fate, while Earth’s refugees attempt a one-way trip from Earth to Mars.
Grave complications arise in Colony One over the upcoming intercept mission, and Mars receives news about the refugees’ launch attempt.
The Mars-bound refugees struggle against the clock to train for the most difficult operation of their lives: landing on Mars.
Reunions and farewells take place as humans on Mars and in orbit begin supply landing operations on the Red Planet.
Crews on Mars and in orbit launch supply drop operations, and prepare for the most challenging operations of their lives.
The remainders of the human race attempt three simultaneous landings on the surface of Mars.