Application of Raman Spectroscopy To Small Satellites in Exploring Solar Bodies

Raman Spectroscopy is an active remote sensing method that can map planetary mineral and chemical abundances and their distributions. Raman spectroscopy can also be used to study the chemical composition of various planetary atmospheres. The remote raman technique utilizes a low power laser to stimulate raman scattering at the substance and a spectrometer receives the returned raman spectrum at the spacecraft. The returned spectrum contains the shifts in frequency, shifted from that of the incident laser light, that are characteristic of the substance. The intensity of the raman spectrum lines is proportional to the amount of the substance present. Thus, with raman spectral information, the identification of a substance and an estimate of its volumetric concentrations can be achieved. The baseline remote raman instrument system utilizes a 10 W krypton laser and a RIRIS spectrally sensitive detector array, cassegran optics, has a mass of 200 Kg, and consumes 1 KW of electrical power. This paper explores the basic concepts of remote raman spectroscopy and postulates an instrument package that is compatible with the mass and size constraints of a small satellite. Various solar system exploratory missions using raman spectroscopy are discussed including the study of the surface of the moon, Earth's upper atmosphere, the atmosphere of Mars, the atmosphere of Jupiter, and the rings of Saturn