Nüwa seeks to become first sustainable city on Mars with 1 million residents CNET 1 hr ago © Provided by CNET ABIBOO Studio Elon Musk plans to have a city on Mars by 2050. But that's a little easier said than done. Human survival on another planet, especially one as environmentally hostile as Mars, depends on finding solutions to four key factors: infrastructure, sustainability, shelter and life support, according to Gisela Detrell, an aerospace engineer at Germany's University of Stuttgart. "There are several issues that we have to face on Mars," Detrell said, "from radiation to pr...