Grumpy Old Geeks Topics Space colonization Topic Space colonization 2 mentions in 1 episode The hosts discuss biological difficulties of sustaining human life in space. Mentions 516: Says the Billionaire... Jul 28, 2021 23:10 six biggest problems with their plans from thinning bones to toxic plants on Mars 23:46 We are built to live on a planet with gravity and oxygen and food and water.