How Many Dogs Have Been Sent to Space?

Almost all dogs sent to space were part of the Soviet space program during the 1950s and 1960s. Approximately 57 dogs flew on Soviet space missions in total, though some individual dogs flew more than once, meaning the number of unique animals was somewhat lower. The Soviets selected stray, mixed-breed females for their calm temperaments and small size, using them as biological test subjects to determine whether living creatures could survive the conditions of spaceflight before risking human cosmonauts.

Key Milestones

Dezik and Tsygan (July 22, 1951) — The first dogs to fly into space, on a suborbital flight. Dezik later became the first two-time space traveler.
Laika (November 1957) — Launched aboard Sputnik 2, Laika was the first animal to reach Earth orbit. There was no plan to return her, and she died during the mission, making her the most famous casualty of the program.
Belka and Strelka (August 1960) — Flew aboard Korabl-Sputnik 2 and became the first dogs to survive orbital spaceflight and return safely to Earth.

Outcomes and Legacy

While many missions were successful, some resulted in fatalities. The program as a whole demonstrated that living beings could endure the physical stresses of launch, weightlessness, and re-entry — findings that directly enabled Yuri Gagarin's historic crewed flight in April 1961. A 2017 academic study by Amy Nelson, published in BJHS Themes, argues that the Soviet space dogs should be understood not merely as passive test subjects but as active participants shaped by Pavlovian behaviorism and the specific conditions of Soviet science, with historical significance tied to both what they contributed and what they experienced.

Post by @jon: How many dogs have been sent to space?

How Many Dogs Have Been Sent to Space?