I did not know there were so many Mars Missions.
so interesting that for each problem solved new ones are both found and created.

Interesting your questions about the psychological states of astronauts, and indeed all people.

Vit. D3 can be made from sunlight or taken in its fat soluble from from ghee or from ruminant fat. But there is more to physical and mental health than nutrition and blue or red light exposure.

Socialising is both necessary and healthy, but it is often the cause of much stress due to the value we place on memories and how we do in fact require them to make sense of sensation.

The intelligence of the astronaut goes way beyond the ability to remember and repeat, or even to use memorised patterns to solve problems quickly.

He must also be a master of self knowledge, so that he can tell when he has become attached to a memory that may cloud his judgement. All this while remaining warm and compassionate from a place of genuine care rather than pride or insecurity.