Another way to test would be a submarine. Estentially the same enviroment, except no windows.

How to go about it is another matter. Perhaps the Navy might lone NASA a decommissoned 688-class sub for training astronauts?

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I calculated the odds of this succeeding versus the odds I was doing something incredibly stupid...and I went ahead anyway. - Crow T. Robot

Godspeed, John Glenn. - Scott Carpenter

And these atomic bombs that science burst upon the world that night were strange even to the men that used them.
- H.G Wells, The World Set Free

To the conspiracy crowd, radiation is a big Boogey Man that inspires terror and death in all who encounter it. - JayUtah