Before scientists can put a man on Mars, they first need to figure out how to get a mission back to Earth, reports the Guardian. An international team is doing just that—developing an $8 billion mission to travel to Mars and return with rock samples and possibly microscopic life. The trip would launch between 2018 and 2023 and would require the expertise and financial backing of NASA, the European Space Agency, and other space programs.
"Everybody knows this is what you have got to do if you want to really get to the bottom of Mars," said a British space expert. But a major issue with a returning Mars mission is introducing Martian microbes into Earth's atmosphere, and the accompanying potential for catastrophic consequences.