I believe most astronauts that have spent any significant amount of time in orbit, have some bone density loss and other atrophy issues. I imagine, especially for the elderly, that bone breakage might be a concern with an extended stay in a low gravity enviroment.
In owning more than a few Newtonian telescopes in my life, I have just a little knowledge concerning parabolic mirrors. But I could use the help of experts in the field... I was wondering if a larger parabolic mirror could reflect a perfect, aberration-free virtual image, of a nearby object. For...