Yuri Gagarin, Alan Shepard, John Glenn, Neil Armstrong—the first wave of space travelers—were military-trained astronauts thought to have the “right stuff” for risky missions.
But early spaceflight wasn’t the exclusive province of men—or even humans. Fruit flies, monkeys, mice, dogs, rabbits, and rats flew into space before humans.
More than three years before Gagarin became the first human in space with his April 1961 journey around Earth, the Soviets famously—or perhaps infamously—sent up a stray dog. Laika was the first animal to orbit Earth but died during her flight. The United States launched a chimpanzee named Ham into space. Happily, he survived, clearing the way for Shepard to became the first American in space in May 1961.