Which was the first animal to orbit the Earth?

Laika, a stray found on the streets of Moscow, launched aboard Sputnik 2 on 3 November 1957. Strays were chosen deliberately on the theory that an animal that had survived a Moscow winter outdoors would tolerate the cold, hunger and stress of the programme.

There was never a plan to bring her back. The re-entry technology did not exist, and the mission was assembled in about four weeks on Khrushchev's instruction to mark the anniversary of the revolution. The Soviet account for decades was that she survived several days and was painlessly euthanised; in 2002 it was revealed she had died within hours of launch, of overheating and panic, after part of the thermal insulation tore away during ascent.

One of the scientists involved, Oleg Gazenko, said much later that they should not have done it - that they had not learned enough from the mission to justify the death of the dog. There is a small monument to her in Moscow, at the research facility that prepared the flight, showing her standing on a rocket.