Well hurry up Nasa!! (Kidding)
I know they had several isolation experiments in the last 10-15 years, in the USA and in Russia, on safe ground in various mocked-up mars bases or simulated “spacecraft”.
The crew members are carefully selected so their characters complement each other and they don’t get “homesick” and so on, pretty interesting topic!
With very interesting results too. Usually it goes well in the first half and the crew is very diligent about keeping the environmental systems running.
Then, after longer time periods, some members start either sleeping too much or too little, and lose their concentration, or they fight and split into factions (e.g. over breaking the simulation to call an ambulance) and walk out.
But they keep repeating the experiment with different crews and it goes better every time, I have the impression.
One is this When a Mars Simulation Goes Wrong - The Atlantic
And the other one was called mars-500.
Before that was Biosphere 2, where they thought, hey, all we have to do is put some fake lakes and soil and oxygen and plants into a dome, lock the door, and voila — I mean, how hard can it be to recreate a livable environment, amiright? well, they learned a 100 new things how the natural balance can tip pretty quickly.
Even when they fail, these experiments are valuable, it’s better to fail in Antarktika, Hawai’i, Arizona, or Moscow than on Mars.