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.

New discoveries have rewritten the history of our solar system, revealing a complex and violent story that begins with the birth of our Sun from the debris of a massive galactic collision, to its eventual fate as a lone zombie star.
It is a dramatic history of elegant beauty and extreme violence. The inner solar system was like a congested highway. Planets crossing lanes, frequent collisions. There were a lot of planets that could have made it but didn't, and we just happen to be one of the lucky ones that did. The players in our solar system's story are more tangled up than we ever imagined. Without all of these things interplaying, the Earth wouldn't have the stable environment that we have today, and life wouldn't be able to exist.

In this captivating final episode of the series we meet some incredible conservation champions on nature's front line, fighting to preserve the future of our beautiful planet. The episode opens with a dramatic rescue operation for the critically endangered black rhino, showcasing the efforts of Dumi Zwane and his team to establish a new breeding colony in a safe haven. The focus then shifts to the Centro Jambatu research center in the Andes, where Jaime Culebras works tirelessly to save the last of certain frog species. The documentary also highlights the efforts of Trang Nguyen, who bravely infiltrates the illegal wildlife trade in West Africa to protect forest elephants from ivory poachers. Meanwhile, in Vienna, Katharina Huchler undertakes a remarkable journey to reintroduce the northern bald ibis to Europe after its extinction 400 years ago. Indigenous leader Alessandra Korap's battle to preserve the Amazon rainforest from exploitation is a key focus, alongside Mohamed Nasheed's fight against climate change to save coral reefs and his country.
This episode addresses the broader issue of habitat destruction, emphasizing its role as a primary driver of extinction. It poignantly demonstrates the interconnectivity of life on Earth and the critical importance of conservation efforts.

In the fourth episode, several women recall their harrowing experiences with one man's heinous attempts at virtual blackmail, aimed at obtaining sensitive sexual material.
A woman tells us: 'I received a message from a man who said: Send me a naked picture or I will kill you'. This young woman was able to add her case to those of other women who were encouraged to denounce and expose the harasser. No one is completely invisible on the Internet.

With the Doomsday Clock the closest it's ever been to midnight, Jane Corbin investigates the proliferation of nuclear weapons across the globe. She visits Los Alamos, home to the United States’ nuclear weapons development facility and the historic home of Oppenheimer’s Manhattan Project.
In Scotland, she reveals the strategy behind Britain’s nuclear deterrent, and speaks to campaigners in Suffolk fighting against US weapons they fear will be based on UK soil. Jane also discovers how many of the global agreements and safeguards that have constrained the spread of nuclear weapons since the 1970s are breaking down.
This is a story told by the scientists, investigators and diplomats who set the clock and have fought to ensure that the ultimate deterrent has not been used in over 70 years.

A look into how the body defends itself against all odds through the stories of a nature survivalist, rancher twins, a doctor who survived Ebola and a cancer therapy recipient. The Immune System, essential to our survival every second, is the most complex and least understood piece of our biology.