This answer explains how the experiment was set up and some of the results of the experiment. My question is why did they have Ham do anything? I understand sending a chimp prior to human flight (better to have a chimp fall to some unknown factor in the harsh conditions of space than a human), but why wouldn't Ham just be a passive passenger?

  • $\begingroup$ Wait, so Carl Pilkington was right?!?!? $\endgroup$
    – Möoz
    May 7, 2019 at 22:41

1 Answer 1


This was to test the change in the chimp's reaction time from the ground to space. It was a human analog experiment--i.e. the results of the test were used to make estimations of how human reaction time would change in spaceflight.

Ham's average reaction time on the ground was .8 second, and during flight he averaged .82 second. The assessment was that he performed well.


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    $\begingroup$ In a larger sense I think there was concern about whether humans would be able to carry out tasks in a sustained free fall environment. "The tests were performed during the Mercury animal flights to ascertain whether the restrained animal, retaining visual and kinesthetic references, could respond normally during weightlessness to a series of problems graded in difficulty and in motivation." From the paper linked in my answer to the earlier question. $\endgroup$ May 7, 2019 at 15:42
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    $\begingroup$ As I was writing my own question about Ham, I did actually read through 4-5 sources. (Yes, I already knew what the answer was, we're allowed to do that.) It should be pointed out that the source you cite here was the best for describing the actual equipment that made the flight. Wikipedia and some other sources conflated that equipment with what was used on Earth for training the chimps, which is just wrong. $\endgroup$
    – DrSheldon
    May 7, 2019 at 16:48
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    $\begingroup$ @DrSheldon I love NASA's history site--it's a treasure trove! $\endgroup$
    – called2voyage
    May 7, 2019 at 16:49
  • $\begingroup$ @DrSheldon if you're talking about the "This New Ocean" link, it's wrong about about the way the console worked, at least in regards to the white light. Assuming that technical paper is right, anyway. $\endgroup$ May 7, 2019 at 22:09

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