astronauts-spend-extended-periods-in-confined-spaces-alone-or-often-with-a-small-crew-this-can-lead-to-feelings-of-isolation-to-stress-as-they-are-far-from-family-friends-when-hes-up-in-space-hell-have-limited-communication-with-the-outside-world-a-lack-of-variety-stimulation-while-anxious-in-the-space-environment-can-lead-to-boredom-a-sense-of-monotony-potentially-affecting-astronauts-mental-health