Laika, the first dog in space. No provisions were made for her return, and she died there 1957

One of the sceintist had regrets about sending Laika into space. Oleg Gazenko:

“Work with animals is a source of suffering to all of us. We treat them like babies who cannot speak. The more time passes, the more I’m sorry about it. We shouldn’t have done it. We did not learn enough from the mission to justify the death of the dog.”