Laika Orbits Earth Aboard Sputnik 2

A Second Sputnik in a Hurry

When Sputnik 1 reached orbit on October 4, 1957, it startled the world and delighted Soviet leaders, who wanted another spectacular achievement soon, in time for the anniversary of the revolution in early November. Engineers had only about a month to prepare. The result, Sputnik 2, was far heavier than its predecessor, a cone-shaped craft of more than 500 kilograms carrying instruments to measure radiation from the Sun and cosmic rays, as well as a sealed cabin for a living passenger.

A Stray From the Streets of Moscow

The passenger was a small mixed-breed dog found as a stray in Moscow. Scientists chose strays on the theory that animals used to cold and hunger would endure harsh conditions better. She was called Laika, a Russian word for a kind of husky-like dog and also for barking. She spent time in training in small cages and in centrifuges that simulated the forces of launch. The cabin had equipment for air regeneration, a feeding system, and sensors for her heartbeat and breathing. There was no plan for her return, because Soviet engineers had not yet developed a way to bring a capsule safely back from orbit.

What Really Happened in Orbit

For years Soviet statements suggested that Laika had lived for days in orbit before dying painlessly. The truth was revealed only in 2002, when a scientist involved in the program, Dimitri Malashenkov, told a conference that she had died within hours, probably from stress and overheating after the satellite’s thermal control did not work as planned. Earlier accounts differ on the exact time, but later sources agree that she did not survive for long. Her flight did show that a living creature could withstand the acceleration of launch and reach orbit.

A Contested Legacy

Sputnik 2 stayed in orbit for about five months and burned up on re-entering the atmosphere on April 14, 1958. The mission’s data on weightlessness and radiation were limited, and a senior Soviet space biologist later said he felt the knowledge gained did not justify the loss of the animal. The flight raised lasting questions about the treatment of animals in research, and Laika became one of the best-known symbols of the early space age, remembered in stamps, memorials, books, and music.

The Other Space Dogs

Laika was not the first dog to fly. Soviet scientists had sent dogs on short rocket flights above the atmosphere since 1951, and some of them, such as Dezik and Tsygan, returned alive. After Laika, the program turned to recovery. In August 1960 two dogs, Belka and Strelka, orbited Earth aboard a Soviet spacecraft and came home safely, a milestone on the road to human spaceflight. Yuri Gagarin made his own orbit on April 12, 1961. Laika’s flight, with all its cost, was a step in a series of experiments that led to the first person in space.