Although gravity keeps our feet firmly planted, some defy earthly forces at all costs. Who are the ones who dreamed of high-flying adventures? Over the course of a decade, the Apollo programs mobilise all resources to send man to the Moon. But this giant leap for mankind couldn't have happened without the first Apollo astronauts who face incredible odds and extreme danger to move science forward. For one little girl with an adventurous spirit, rules and records are made to be broken. Amelia Earhart dominates the male-driven world of flying, but risks life and limb along the way. And for Austrian tailor Franz Reichelt, seams and stitches promise an entry into the exciting world of aviation. Though history remembers his failure, he leaves his tick on the timeline of parachute innovation.

Breaking the glass ceiling is never easy, but for these female inventors, science comes at an added price. When Marie Curie discovers radioactivity, she earns not one but two Nobel Prizes. But though she is devoted to her subject matter, it puts her in incredible danger. How does her selflessness open a whole new world of particle physics? When the 36-year old Dian Fossey packs up her life to study mountain gorillas, she has no tracking experience, no university degree, and no idea what she's in for. How does she become one of the most iconic and controversial primatologists to have ever lived? And when the entrepreneurial Elizabeth Fleischmann gets hold of a new invention, she transforms X-rays into a tool for medical imaging. How does her can-do attitude allow her to enter the world of male-dominated medicine, even as the tools of her own innovation take a silent toll?

Nature is powerful and can snuff out life in an instant. But for three intrepid adventurers, nature holds mysteries just waiting to be discovered. When most others flee, Tim Samaras drives into the eye of the tornado. His technological innovations, and sheer nerve, give new insights on one of nature's most dangerous forces. For David A. Johnston, it's a race against time to study the science of volcanic eruptions. As Mount Saint Helens gets ready to blow, this young scientist puts his life on the line for science and prevents an even deadlier disaster. When George Mallory sets his sights on the world's highest peak, he knows he must forge his own path to be the first to summit Everest. What does it take for him to reach these unclimbable heights, and does he succeed? We examine the evidence almost a hundred years later.

Some discoveries lie in wait for those brave enough to venture out. From hidden cities in the jungle to dinosaur fossils and seeds in far-flung locales, the prize goes to those willing to take the risk. The world watches with bated breath as adventurer Percy Fawcett enters the Green Hell of the Amazon jungle. Does he find a lost city in this dangerous expanse? And at a time when America sees a great expansion, two of America's first paleontologists go to war over dinosaur fossils. How far will O.C. Marsh and Edward Drinker Cope be willing to go in their brawl over prehistoric beasts? Confronted by famine, Russia sends a botanist to find the seeds to save an empire. But as political winds shift, Nikolai Vavilov becomes champion for science. How does he fight for the truth when no one else will?

Although modern medicine is capable of incredible feats, the ability to treat the human body follows hundreds of years of experimentation, at times with deadly results. When an epidemic of yellow fever strikes American soldiers in Cuba, Jesse Lazear journeys to the front. In a race against time, he puts himself in harm's way to uncover the source of the epidemic and prevent its spread. When a revolutionary science fiction writer anticipates modern blood transfusions, does anyone take him seriously? As Alexander Bodanov turns metaphor into medicine, he puts his own body on the line. And before much is known about the body's internal systems, a God-fearing scholar named Michael Servetus makes an incredible observation about human circulation. How do his religious beliefs bury the discovery until almost 100 years later?

Some names stay with us over hundreds and even thousands of years. Great thinkers left their mark on scientific discovery, although some were far ahead of their time. For Galileo Galilei, new tools allow him to make bold statements about the nature of the Universe. But what happens when what seems obvious flies in the face of accepted truth? In ancient Alexandria, scholar Hypatia makes contributions to mathematics and science. But how does her celebrity become a double-edged sword? And for a roving scholar unwilling to bow down to authority, every new city offers a new pulpit for his religious and astronomical beliefs. But when there's nowhere left to run, how does Giordano Bruno face those he's angered in his wake?

Studying Earth's creatures can yield profound scientific insights, but meddling with the natural world can have lethal consequences. Snake enthusiast Kevin Budden risks everything in his pursuit of Australia's most venomous reptile. While expanding our catalogue of birds, ornithologist John Cassin plays with poison beneath their plumes. One of Britain's greatest entomologists, Harold Maxwell-Lefroy, falls victim to the very insecticide he hopes will safeguard the world.

To save millions of lives, medical martyrs have put themselves in the line of fire. Eighteenth-century obstetrician Ignaz Semmelweis plants the seeds for germ theory before a stunning downfall. Peruvian hero Daniel Carrión chases down a deadly disease using a dangerous experiment. Deep-diving inventor Sieur Freminet plays a lethal game of trial and error as he tests out his revolutionary diving suits.

Intrepid explorers have ventured into the world’s most unforgiving landscapes in a relentless quest for knowledge. Biochemist Peng Jiamu braves the shifting sands of China’s northern desert in search of its hidden secrets. In the 18th century, Jean-Francois Laperouse sails into the remote Pacific, determined to find the elusive Northwest Passage. Ancient Roman scholar Pliny the Elder confronts the wrath of Mount Vesuvius to harness the wisdom of the natural world.

Every innovation started as an idea -- but not all ideas leave their inventors unscathed. To prove the possibility of heavier-than-air flight, Otto Lilienthal needs proof of concept. To demonstrate his revolutionary plane on tracks, Valerian Abakovsky enlists an unfortunate band of VIP passengers. As a printing press promises a golden age of publishing, inventor William Bullock falls victim to his own design.

Examining molecules, compounds, and chemicals, scientists take risks on great discoveries. Carl Wilhelm Scheele uncovers the stuff of life as he tinkers with deadly substances. Rosalind Franklin gives humanity the first image of the double-helix, but her contribution seems to fall by the wayside. Against all odds, female chemist Alice Ball develops the cure for leprosy, though a twist of fate means she’ll never see its impact.

Tinkering with the unseen can have dangerous consequences. As lightning flickers over St. Petersburg, a 19th-century physicist attempts to harness electricity. In an ultra-secret lab, a Canadian scientist brings a dangerous nuclear reactor to the edge of annihilation as part of the Manhattan Project; and, as an astronomer observes distant star formations in the darkest lab on earth, he is suddenly struck by a mysterious illness.