As training begins, the crew members process the physical, mental and technical demands being placed on them. The group is going to be in some intentionally uncomfortable situations and, to see how they do as a team. A climb of Mt. Rainier puts them to the test.

A fighter jet ride prepares the crew for the G-forces of spaceflight. Haley, Sian and Chris relate the emotions they experience as launch approaches.

Follow the shocking, yet humorous, journey of an aspiring environmentalist, as he daringly seeks to find the real solution to the most pressing environmental issues and true path to sustainability. Discover 'The Facts' http://www.cowspiracy.com/facts

What might happen if the first manned mission to Mars crashes hundreds of miles from the rocket that would take them back home? Could they survive the crash, and travel across the brutal Martian surface to their home ship? We'll show what the astronauts would have to do to survive dust storms and space radiation, while extracting vital resources like water from the Martian soil itself. It's a dramatic vision of the very near future, where survival can depend on pre-industrial technology and human ingenuity.

In the fourth episode, Morgan Freeman examines how different faiths see the creation of the world, taking him on a journey to the Vatican, Cairo and the jungles of Guatemala.

In the dark depths of the oceans, nearly 90% of all species light up the darkness from within. These creatures flash, sparkle, shimmer, or simply glow. Whether it’s to scare off predators, fish for prey, or lure a mate, the language of light is everywhere in the ocean depths, and scientists are finally starting to decode it. Discover surprising ways to harness nature’s light—from tracking cancer cells to detecting pollution, lighting up cities, and even illuminating the inner workings of our brains.