Question: why did you guys send a monkey in to space instead of a nother animail

Michael Nolan answered on 20 Jan 2021:

At the start of the space program NASA had used primates, such as chimpanzees since these are close relations to humans (it is common to do experiments using primates instead of humans).
Using primates means that you get a very good sense of how something affects humans, but without having to use humans as experimental subjects.
As you can imagine, when testing new rockets and space technology, it would have been considered too dangerous to send humans in the early flights as the death of a human in these tests could have lead to cancelling the program entirely. However, if a chimp were to die the impact is much smaller.
So you reduce the risk but still get information that is really useful.
Also, chimps can be trained to respond to different stimulus,whereas animals such as dogs or cats are much harder to train.
Whether you agree with this or not is of course your own opinion, but we probably would have not had a successful moon landing without the contributions from the primates who went into space on the early test flights.