Every single day is the same as the next for 6 solid months. it is essentially a scientifically decorated limited living room, kitchen and toilet. Every second being weightless and eating a boring assortment of vacuum packed food with some difficulty, where every spec of debris floats around the cabin and poses a failure hazard. They cannot allow bits and pieces however small to float around indiscriminately.The usual daily tasks of hygiene, washing, personal toiletries and housekeeping are not exactly simple or private.
No Doctors, Surgeons or other medical aid if one is taken ill, no repair man available if things go wrong, no walkies and no shopping expeditions. In fact no nothing. If a member of the crew cannot do it, it does not get done. The view outside never changes, it is the same every single day and night.
This entire period is a monumental challenge to personal sanity and a number of these astronauts have been in space for a year or more.
To me, it is a massive threat to mental stability and a rather optimistic challenge to maintaining good health over the entire mission period. The threat of sudden death from a variety of causes is a constant factor and of course the possibility of never returning to Earth and being marooned in space for all eternity, is a very real prospect. The only taxi service to and from the ISS is currently an exclusive facility provided only by the Russians at an exorbitant fee. America opted out with their discontinuation of the Space Shuttle.
It matters little how much these people are trained, when in space training is simply a vital survival skill, that is all. The rest is back to GOOD LUCK and personal mind control.
Comments please about the orbital situation of sheer endurance these astronauts have to sustain constantly for periods of 6 months or more.