VISIT CNBC.COMX South by Southwest South by SouthwestBuzz Aldrin says this is the problem with Elon Musk’s plans for Mars Catherine Clifford 1 Hour Ago CNBC.com show chapters Elon Musk's plan to colonize Mars has one big problem, according to astronaut Buzz Aldrin    1 Hour Ago | 01:13 SHARES SpaceX founder and CEO Elon Musk's plans to colonize Mars...