A compact LiDAR spectrometer for lunar surface science and in situ resource utilization

Identification of water ice, volatiles, and mineral resources on the lunar surface is essential for human exploration and settlement on the Moon. Fibertek is developing a Compact Lidar Spectrometer (CLS) with support from NASA Marshall Space Flight Center to rapidly scout water ice and other volatiles from ranges of up to several kilometers. The instrument is designed to be compact and deployable from a rover. It uses a tunable optical parametric oscillator (OPO) to generate laser light across NIR (1.45-1.85 μm) and MIR (2.5-4 μm) spectral regions. To collect a full spectrum, the CLS collects surface lidar signals as the laser is tuned across the spectral range. In this paper, we present results from a breadboard version of the CLS built at Fibertek. The OPO operated from 2600 to 4400 nm and showed excellent spectral repeatability. We collected reflectance spectra from lab samples by illuminating the samples and measuring scattered photons while tuning the OPO. These spectra showed very good agreement with published spectra, and they featured absorption signatures associated with water. We also present a design concept for a deliverable CLS module with a pathway to space, and we discuss efforts to improve data quality and calibration of the CLS instrument.