Principles of generosity and prosperity inform the selection of the last two crew members: Christopher Sembroski, a former member of the U.S. Air Force who served in Iraq and now works as a Lockheed Martin engineer, and Sian Proctor, a professor of geosciences and two-time NASA astronaut candidate. Excitement for the flight ramps up, but anxiety lingers.

Follow the four civilians as they launch into space on a three-day trip orbiting Earth and reaching an altitude higher than that of the International Space Station. The SpaceX Dragon mission, dubbed Inspiration4, is making history as the first all-civilian mission to orbit.
In the first episode, preparations begin for the mission. The commander is Jared Isaacman, a billionaire entrepreneur who purchased the flight for all four passengers, and the second crew member is a 29-year-old cancer survivor, Hayley Arceneaux.

In Southeast Alaska, there's an ice-bound Eden that harbors possibly the richest temperate rainforests of all. Where the coastal mountains meet the Pacific, lays the Alexander Archipelago, a remote island chain running for almost 300 miles along the Alaskan Panhandle. This frozen frontier is one of the last great wildernesses of North America. And a stronghold for the country's highest diversity of megafauna, feasting on the abundance of fleeting summers to make it through relentless winters.

At the far tip of South America, lies a magical realm that seems frozen in time. Known as 'the end of the world', this is Patagonia. Vast glaciers shaped it into an Eden like no other. Adaptable and resilient creatures evolved unique survival strategies to flourish across its remarkable habitats. From precipitous mountain citadels and icy desert plateaus windswept steppe uplands through remote, primal forests to a mosaic of glacial valleys. To thrive here is to be as extreme as the land itself.

At the very end of East Africa's Great Rift Valley, there's a 'land that time forgot'--the rolling grasslands of the Luangwa Valley. Seemingly untouched plains teem with Africa's most iconic animals. Some are unique to this place, others are critically endangered elsewhere.
Here, prey exist in remarkable balance, each taking advantage of the secret at the heart of this Eden, the mighty Luangwa River and its dramatic annual transformation from dusty inferno to emerald paradise.

Beneath Yellowstone National Park, lies the biggest volcano on Earth. An eruption in the past was so big it plunged the earth into a volcanic winter that lasted years. A super-eruption would be more than millions of Hiroshima bombs going off all at once. It would be even worse than an asteroid impact: Entire cities lost beneath ash, people and animals crushed alive, power networks destroyed, sun dimmed across the globe, harvests failed, widespread famine. Could this nightmare really happen? We will use the latest scientific data to uncover the danger beneath us, as we see our planet like never before.