Sputnik 2, launched in November 1957 carrying the first living creature into orbit — the dog Laika, who died within hours of launch from overheating — completed 2,570 orbits before atmospheric drag pulled it to a fiery reentry on April 19, 1958. Its long, visible decay became an early lesson in orbital mechanics and space debris, and Laika's fate reignited debate about the ethics of animal use in the Space Race.
When the Soviet Union launched Sputnik 2 on November 3, 1957, barely a month after the first Sputnik stunned the world, it carried a small stray dog named Laika strapped into a pressurized capsule with no plan for her to return alive. Soviet officials claimed for decades that she survived about a week before a scheduled euthanasia; it later emerged she died within hours of launch when the capsule's thermal insulation failed and temperatures soared, a fact the Kremlin suppressed until 2002.
The spacecraft itself, a 1,120-pound cone-shaped capsule, remained in orbit for five more months, tracked by astronomers and amateur radio operators worldwide as a ghostly reminder of the mission. Its decaying orbit, gradually lowered by atmospheric drag, made it one of the first objects whose reentry taught scientists real data about orbital lifespan.
On April 19, 1958, after 2,570 orbits, Sputnik 2 disintegrated in the atmosphere. The mission had proven that living creatures could survive launch and short-term weightlessness, paving the way for human spaceflight, but Laika's death also became one of the earliest flashpoints in the ethics of animal experimentation in science, a controversy that only intensified once the full story became public.
Key people: Sergei Korolev