We present a demonstration of an instrument system built at NASA Ames Research Center, for in situ near-infrared spectral observations and visible imagery of airless bodies. The Near-InfraRed Volatile Spectrometer System (NIRVSS) is comprised of two main structural components: the spectrometer box, which houses two NIR spectrometers, and the “bracket assembly” which includes a CMOS camera, 8 different wavelengths of illuminating LEDs, optical fiber mounts for the spectrometers, a near-infrared source lamp, and 4 radiometers capable of measuring surface temperatures from 115 to 360 K. The primary science goal of NIRVSS is to detect and characterize the abundance of OH and other volatiles on planetary surfaces.
The current instrument design is driven primarily by requirements of the Resource Prospector rover mission to the lunar poles in ~2022. For this mission, NIRVSS will serve as a prospecting instrument, mounted to the underside of the rover, viewing the ground over which the rover will traverse. The two spectrometers span adjacent wavelength ranges (1.59 - 2.39 and 2.31- 3.39 microns) that target the detection of OH bands indicative of water and other volatiles on the lunar surface. The near-IR tungsten filament source on the bracket projects a beam onto the ground beneath the rover, which is scattered and reflected back up in to the optical inputs for the spectrometer fibers. The four radiometers (8, 10, 12.5, and 25 microns) serve as calibration instruments for low temperature surfaces with blackbody peaks outside of the range of the spectrometers. Finally, the newly-updated Drill Observation Camera (DOC) is outfitted with 8 LED illumination sources with the following peak wavelengths: 410, 540, 640, 740, 905, 940, 1050, and a white broadband LED.
The capabilities of the NIRVSS instrument are relevant for all airless bodies, including asteroids, Phobos and Deimos, and Mercury. Remote measurements indicate that surface or subsurface hydration will be present at each of these planetary surfaces, particularly in regions protected by permanent shadow. The NIRVSS instrument provides a complementary suite of instrument components that can corroborate evidence of this hydration from planetary surface. We will discuss a diversity of potential uses for the instrument, and showcase representative laboratory measurements of planetary analog materials.