For some of us a test of human endurance entails leaving our homes without a scarf when the weather dips ever so slightly below the freezing mark. So imagine the challenge of traveling 1800 miles through the coldest weather imaginable without so much as a ski lodge in site. That’s the task being undertaken by Ben Saunders and Alastair Humphreys on their SOUTH expedition. The two men will be making the first ever return journey from the coast of Antarctica to the South Pole and back again using their feet as their only transport. The trek, in addition to being a mind and body numbing challenge, aims to focus on creating a long term commitment to environmental stewardship responsibility. Though set to be the longest unsupported polar expedition in history — the the equivalent in length of a staggering 69 consecutive marathons — the participants, along with the Carbon Neutral Company, are doing their best to ensure that the undertaking leaves no carbon footprint. The journey begins in late October of 2009, but you can follow the preparations leading up to it at the expedition’s official blog.