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.

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.

The white hole is a region of spacetime and that cannot be entered from the outside, although energy-matter, light and information can escape from it. In this sense, it is the reverse of a black hole. Einstein predicted strange cosmic phenomena known as white holes, but scientists have yet to prove they exist.
Today, astronomers race to find the clues that can unlock the secrets of white holes. They investigate the tiny black holes that hide in the most ancient parts of the universe to finally find the smoking gun.

The global cyberwar is heating up and the stakes are no longer limited to the virtual world of computers. Now, thanks in part to secret documents released by Edward Snowden, the true scale of the National Security Agency's scope and power is coming to light. Besides spending billions of dollars to ingest and analyze the worlds' electronic communications, the NSA has set out to dominate a new battlefield—cyberspace. We examine the science and technology behind cyber warfare and asks if we are already in the midst of a deadly new arms race". Already, highly sophisticated, stealthy computer programs such as the notorious Stuxnet worm can take over and even destroy the control systems that regulate everything from food factories to gas pipelines, power plants, and chemical facilities—even our cars. While the destruction of Iranian centrifuges may have delayed Iran’s bomb program and forestalled an Israeli attack, the attack has opened a Pandora's Box, and now America's own critical infrastructure is vulnerable to retaliation and attack. With leading defense experts and investigative journalists who have probed the murky realm of criminal and strategic hacking, NOVA examines the chilling new reality of cyberwar in which no nation or individual is safe from attack.

Right now cosmic forces prowl the universe and threaten man's very existence. They're asteroids and comets; they've left their imprint on planet Earth, literally. Initially helping to build planets through violent collisions, during this fiery bombardment period they may have even seeded Earth with water and the building blocks for life. Since the turbulent formation of the solar system, these space rocks have continued to impact Earth. Some have been so violent that they've led to mass extinctions, including one that wiped out the dinosaur. New theories suggest that asteroid and comet dust harbour deadly viruses that may have triggered some of our worst pandemics. The possibility of future collisions remains a legitimate threat yet despite their dangers, asteroids and comets may hold vital natural resources, which could actually preserve

Almost everything we know today about the beautiful giant ringed planet comes from Cassini, the NASA mission that launched in 1997 and arrived at Saturn in 2004. Since then, the space probe has been beaming home miraculous images and scientific data, revealing countless wonders about the planet, its rings and 62 moons - including some that could harbor life. When the mission approached its final days, it attempted one last set of daring maneuvers - diving between the innermost ring and the top of Saturn's atmosphere.
Aiming to skim less than 2000 miles above the cloud tops, no spacecraft has ever gone so close to Saturn, and hopes were high for incredible observations that could solve major mysteries about the planet's core. But such a daring maneuver comes with many risks and is no slam dunk. In fact, slamming into rocks in the rings is a real possibility. Join NASA engineers for the tense and triumphant moments as they find out if their bold re-programming has worked, and discover the wonders that Cassini has revealed over the years.