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.

Sal takes uncharacteristically desperate measures in the face of new federal charges, an unearthed paper trail and increasing pressure on a confidant.

The Rosetta mission was a ground-breaking expedition to land on a comet for the first time, the 67P/Churyumov-Gerasimenko comet. The Rosetta mission tries to answer our most fundamental questions and to change our understanding of the cosmos forever. Special access reveals what this cutting-edge journey discovered and how these mysterious objects helped create life on Earth.

In astronomy, we've been looking at different kinds of light and opening up the universe a little bit more of the time. But then in 2015, the roof came off. Something happened that changed everything, the ability to see waves in space and time itself. Gravitational waves help us roll back the clock to the dawn of time, discover epic cosmic collisions, on make Earth-shaking discoveries. Gravitational waves are the biggest game changer since the invention of the telescope. We have a completely new universe to view now. A new exploration of space is just beginning.

Professor Brian Cox continues his epic exploration of the cosmos by looking at the faint band of light that sweeps across the night sky - our own galaxy, the Milky Way. The Sun is just one of almost 400 billion stars that form this vast, majestic disk of light, our own home in the universe. Thanks to a cutting-edge space we’re finally able to reveal the Milky Way’s dramatic history and predict its cataclysmic future.
Our galaxy started out a fraction of the size it is today, and Gaia telescope has revealed how it grew over the eons. Beautifully rendered VFX based on the very latest Gaia data has uncovered the remarkable story of our galaxy’s evolution. As our young galaxy encountered rival galaxies, it experienced a series of violent growth spurts and intense periods of cataclysmic change while battling to survive. Each time our galaxy feeds, a new era of star formation begins, fuelled by incoming torrents of fresh gas and energy. And there is another collision to come. Another, larger galaxy is coming our way. Andromeda is heading straight for us at a quarter of a million miles per hour. The Milky Way’s long-term fate is in the balance.