LAMP: The Lyman Alpha Mapping Project aboard the NASA Lunar Reconnaissance Orbiter Mission

摘要

The Lyman Alpha Mapping Project (LAMP) is an ultraviolet imaging spectrograph recently selected for NASA's Lunar Reconnaissance Orbiter (LRO) mission. Its main objectives are to (ⅰ) identify and localize exposed water frost in permanently shadowed regions (PSRs), (ⅱ) characterize landforms and albedos in PSRs, (ⅲ) demonstrate the feasibility of using natural starlight and sky-glow illumination for future lunar surface mission applications, and (ⅳ) characterize the lunar atmosphere and its variability. The LAMP UV spectrograph will accomplish these objectives by measuring the signal reflected from the nightside lunar surface and in PSRs using both the interplanetary HI Lyman-α sky-glow and FUV starlight as light sources. Both these light sources provide fairly uniform, but faint, illumination (e.g., the reflected Lyman-α signal is expected to be ～10 R). Thanks to LAMP'S sensitivity, by the end of the 1-year LRO mission the SNR for a Lyman-α albedo map will be > 100 in polar regions exceeding 1 km~2 (and > 15 for 100x100 m~2 polar regions), allowing the characterization of subtle compositional and structural features. The LAMP instrument is based on the flight-proven ALICE series of spectrographs that are flying on Rosetta and built for flight on NASA's New Horizons Pluto-Kuiper Belt Mission.