In-situ Resource Utilization (ISRU) is going to be a critical technical component of any human expansion out into the solar system. Our first challenge with utilizing those resources, though, is finding them. We know how, at least in theory – send a probe to an asteroid, or a particular part of the Moon, and take a sample, maybe analyze that sample with some spectrographs, or send it back to Earth to be poked and prodded. The problem with this methodology is simple – it’s expensive….