Surface and borehole neutron probes for the construction and resource utilization explorer (CRUX)

The construction and resource utilization explorer (CRUX) project aims to develop an integrated, flexible suite of instruments with data fusion software and an executive controller for the purpose of in situ resource assessment and characterization for future space exploration. The instrument suite includes two neutron detectors, the surface neutron probe (SNeuP) and the borehole neutron probe (BNeuP) to help locate and assess potential hydrogen-bearing resources at the lunar poles and on Mars. SNeuP offers a rover-borne surveyor function for locating near-surface water (or other hydrogenous volatiles) in a lightweight (481 g) package. BNeuP serves a borehole prospector function by determining the stratigraphy of hydrogenous subsurface layers to depths of up to 10 meters within a drill string segment. The instruments´ heritage includes the Lunar prospector neutron spectrometer and numerous programmatic space instrument applications at Los Alamos. We have tested the SNeuP and BNeuP prototypes and have demonstrated their ability to detect near-surface hydrogenous materials. In a lunar or Mars exploration application the instruments could be passive, sounding materials through the detection of neutrons produced by cosmic ray spallation in soils and ice. However, in terrestrial field tests we have used a neutron source to ´illuminate´ surrounding materials and gauge the instruments´ efficacy