When Ed White, clad in his gleaming space suit with a large American flag on his left shoulder, eased himself outside his Gemini spacecraft in 1965, Americans had a new space hero. They also learned a new acronym: EVA, short for extravehicular activity, more commonly known as "spacewalking." Though few understood the tremendous risks White was taking in his twenty-two-minute space walk, Americans watched with immense pride and patriotism as White, tethered to Gemini 4, propelled himself around the spacecraft with a pressurized oxygen-fueled zip gun. But White's struggle to fit his space-suited body back inside the claustrophobic Gemini spacecraft confirmed what NASA should have known: spacewalking wasn't easy.

More than fifty years and hundreds of space walks later, the art of EVA has evolved. The first space walks, preparation for walking on the moon, intended to prove that humans could function in raw space inside their own miniature spacecraft—a space suit. After the end of the lunar program, focus was turned to long-duration flights on space stations in low Earth orbit, and space walks were crucial to the success of these missions. The construction of the International Space Station required hundreds of hours of work by spacewalkers. Into the Void tells the story of those who have ventured outside the spacecraft into the unforgiving vacuum of space.