Along with a handful of other dogs, Laika was trained by scientist Dr. Oleg Gazenko to ride inside the small chamber aboard Sputnik 2, a satellite equipped to monitor an animal's vital signs from orbit. Her easy personality helped her get selected for the mission - but it also endeared her to the mission team perhaps more than they ever expected a test-subject could.
"Laika was a wonderful dog .... quiet and very placid," one of the scientists involved later told NASA. "Before the flight [...] I once brought her home and showed her to the children. They played with her. I wanted to do something nice for the dog."
Laika didn't survive for more than a few days inside that crude early spacecraft, but she did pave the way for a future of manned space flights. Her contribution as a pioneer has made her a celebrated figure in Russia and beyond, though for those who knew her best - not as a cosmonaut, but as a dog - cutting her life short still wasn't worth it.
"The more time passes, the more I'm sorry about it. We shouldn't have done it," Dr. Gazenko lamented decades later. "We did not learn enough from the mission to justify the death of the dog."