Experimental Results of Autonomous Microrover Exploration and Mapping of an Analog Planetary Pit

Hundreds of pits on the Moon and Mars expose unique unweathered geology on their walls, and some may access habitable caves. Small, autonomous rovers could explore, image, and map planetary pits from the rim, capturing close-range, low-angle, long-exposure imagery that cannot be captured from orbit. The small but high fidelity models must be processed in-situ for the short-duration small missions of our time with limited bandwidth since the raw imagery required for modeling is at least an order of magnitude greater than what can be downloaded in a lunar day. The vast raw imagery is the basis for modeling pits with the accuracy, resolution and lighting corrections necessary for morphology study and search for cavernous openings. This work develops and evaluates several component technologies for these explorations. A safe-approach behavior is developed and employed to navigate pit rims to vantages for acquiring images. Images from multiple vantages are fed to a specialized incremental pit modeling pipeline that computes the high-resolution 3D pit models. The technologies are manifested aboard a prototype micro rover and demonstrated at a terrestrial pit having size and shape comparable to known planetary pits. In multiple end-to-end mission simulations, these techniques are shown to reliably produce unprecedented, accurate, high-coverage pit models.