Before any human could fly into space, scientists needed to know if living things could survive the journey. Could a body handle the powerful forces of a rocket launch? Could a heart keep beating while floating in zero gravity? To find out, they chose a dog. On November 3, 1957, a small dog named Laika was launched into orbit aboard the Soviet spacecraft Sputnik 2. Laika was a stray dog found on the streets of Moscow. Scientists chose strays because they were used to harsh conditions. She was trained to sit in a tiny capsule and eat food from a special tube. Laika's flight proved that a living creature could survive the launch and reach orbit. Her heartbeat and breathing were monitored from the ground. The data showed that her body handled the stress of liftoff. Sadly, the mission was designed as a one-way trip. There was no technology to bring the capsule back to Earth. Laika died within hours of reaching orbit, likely from overheating. Her sacrifice sparked a worldwide debate about the ethics of using animals in experiments. Despite the controversy, Laika's mission helped make human spaceflight possible. Four years later, Yuri Gagarin orbited Earth.