Spacepen Bullet When closed, the Bullet Space Pen is the perfect size to carry in your wallet, pocket, purse, car glove box, organizer or toolbox. When open it's a full sized, evenly balanced writing instrument. The original Bullet Space Pen was conceived in July of 1948. Paul Fisher was soon machining a new pen design shaped from solid aluminium. It became the first Fisher ball point pen, the #400 Bullet Pen, and arguably the most popular pen of the twentieth century. Cited as an outstanding example of industrial art, the classic design of the Fisher Bullet Pen has been exhibited for years in the New York Museum of Modern Art. The Bullet's timeless styling has been the topic of many art books and magazine articles. Often imitated but never duplicated, the Fisher Bullet Space Pen continues to be our most popular pen.