TEMMI, a Three-dimensional Exploration Multispectral Microscope Imager for planetary exploration missions

Abstract In 2009, the Canadian Space Agency funded a project to create a field-deployable high-resolution microscope with 3D and multispectral capabilities. The instrument, called the Three-dimensional Exploration Multispectral Microscopic Imager, or TEMMI, was designed to be mounted on the manipulator-arm of a robotic rover for use in analogue planetary exploration missions. TEMMI can acquire images with a resolution as high as 2.2 μm/pixel for an area 5.7 × 2.1 mm in size. As a result, grains sizes as small as ∼6.6 μm (very fine silt) are observable. The instrument has three sets of nine distinct light-emitting diodes with wavelengths ranging from 365 nm to 850 nm. In the 2015 and 2016 CanMars Mars Sample Return analogue mission, this prototype was utilized to observe micro-textures and features of various rocks and unconsolidated samples. Microscopic image data were used to provide micro-scale context for these samples, and was synthesized with other rover-based instrument data on the collected samples to aid in geologic classification and to determine formation and geologic histories of the samples. In addition to colour images acquired during the CanMars mission, TEMMI has also been tested and used extensively in a laboratory setting. The multispectral capabilities of TEMMI demonstrate that it is capable of identifying olivine in a mantle xenolith sample at the mineral-grain scale. The ability of TEMMI to generate 3D models at the micro-texture scale enables observations of intricate flow features that would not be visible at larger scales. While additional development has been identified in order to raise the Technical Readiness Level of TEMMI, the combination of laboratory studies and analogue deployments have demonstrated that it can be a key tool for planetary scientists.