Many book collectors build their libraries around a specialized niche. Space and exploration books are a popular theme, allowing investors to indulge their fascination with an uncharted world while increasing the monetary value of their collection. By purchasing a hand-signed biography of an esteemed astronaut, you'll own a piece of history while commemorating the author's immeasurable contributions. Here, you'll find titles signed by some of the most notable figures in space exploration, including the first astronaut to orbit the earth (John Glenn), the first man to climb Mt. Everest (Sir Edmund Hillary), the first person to break the sound barrier (Chuck Yeager), and many more.