I believe people involved in the program have since admitted that this was mostly to commit suicide in case they got stuck with no way home

feels like you just invented this lie on the spot

Surely a chemical/biological solution would have been easier, cheaper, lighter, and less likely to fail.

I imagine you can't take turns easily once there's a hole in the ship.

On the other hand, there are legitimate predators that will hunt and eat humans in Siberia. One team encountered wolves that they had trouble fending off, so they upgraded the pistol to a more formidable shotgun/rifle combo.