Would like to point out there is no plot hole in regard to why they are not sending up the replicas instead. It was explained in the first few minutes by David Ross survival of the human body is central to the mission. That's why they go back for physical every Friday, as opposed to only where there is an emergency / maintenance.
I thought this must be the case when someone pointed out the plot hole, and rewatched the film to confirm it. It also makes it genius to set it in alternate1969, since that historical context makes it believable for science to still be testing the survival of human body in space. Also why I gave it a 10, because so many elements of the story won't work in present day / future (e.g. Neglect of mental health, son being largely in the background, no social media / smartphone, wife's submission etc).
Hope this helps anyone who couldn't sleep due to this so called plot hole.
I thought this must be the case when someone pointed out the plot hole, and rewatched the film to confirm it. It also makes it genius to set it in alternate1969, since that historical context makes it believable for science to still be testing the survival of human body in space. Also why I gave it a 10, because so many elements of the story won't work in present day / future (e.g. Neglect of mental health, son being largely in the background, no social media / smartphone, wife's submission etc).
Hope this helps anyone who couldn't sleep due to this so called plot hole.