Iran claimed Monday to have sent a monkey into space. The country previously launched smaller animals into the final frontier, including a rat, worms, and two turtles. “What do space programs look for in animal astronauts?” asks an essay in Slate.com
“Portability, experience in the lab, and coolness under pressure. For more than 60 years, space programs have sent animals into space for the same reason coal miners sent canaries into the coal mine: to test for dangerous conditions. To select which species to send, scientists have long looked for a few key traits. First, the animal astronauts should be small, to fit in a spacecraft’s necessarily compact
quarters. Second, they should be light, to avoid burdening the rocket.Third, scientists choose animals that they’re already used to studying. For example, scientists used to working with mice might send mice. Since they’ve done dozens of experiments on the species, they’ll know if Mickey is acting unusual when he returns.
The Soviets chose to launch many of their most important test flights with dogs because they had experimented on them since the beginning of the 20th century (most famously in the experiments of Ivan Pavlov).
They also thought that dogs would be less fidgety in confined spaces. The Americans chose to work with monkeys and chimpanzees for the same reason—they were accustomed to working with them in the lab—though they also valued monkeys’ and chimpanzees’ many physiological similarities to humans.
“Once rocket scientists have settled on their species, they often run tests to determine a standout member of the pack. After the Soviets settled on launching canine cosmonauts, their recruits were subjected to a series of Right Stuff–style tests to find the top dog. The animals were trained for confinement (by being placed in tight cells), for loud noises and vibrations (by being subjected to loud noises and vibrations), and to relieve themselves in their space suits (there was a special sanitation device attached to the suit). Only female dogs were eligible, because they were an easier fit with the sanitation devices, and only stray mutts were tested, reportedly because they thought the street-tough animals would fare better in extreme conditions. It was after scoring high in these tests that Laika, who was thought to be particularly easy-going, was selected to be the first animal to orbit Earth. On Nov. 3, 1957, Laika was blasted into Earth orbit on the Sputnik 2, never to return. (Laika, or “Muttnik,” died after a few hours, and the Sputnik 2 burned up a few months later.)”