If humanity hopes to establish a lasting presence on Mars, it will have to learn to live off the land. Ambitious exploration efforts have always aimed for self-sufficiency, but the need is especially acute when the new terrain being traversed is another planet. Extensive resupply from Earth would be prohibitively expensive, experts say, so exploiting Red Planet resources is crucial to making pioneering manned missions affordable in the short term and Mars settlement sustainable over the long haul. "We want to move and explore in a very similar manner that weve done in the past, so that we can live off the land to make all these missions very cost-effective and more efficient," Prasun Desai, acting director of the Strategic Integration and Analysis Office in NASAs Space Technology Mission Directorate, said last Tuesday. A Space.com story via Yahoo! News.