P060-01
The Lunar Polar Hydrogen Mapper (LunaH-Map) Mission: Low-Altitude Hydrogen Mapping of the Lunar South Pole With a Very Small Spacecraft
Monday, 14 December 2020: 16:00
Virtual
Craig J Hardgrove1, Richard D Starr2, Thomas H Prettyman3, Igor Lazbin4, Erik Bjorn Johnson5, Bob Roebuck4, Joe DuBois6, Nathaniel Struebel6, Anthony Colaprete7, Patrick Hailey8, Derek Nelson9, Jeremy Knittel9, Michael Tsay10, Alessandra Babuscia11, Lena Heffern1, James F Bell III1, Darrel Drake12, Andrew Klesh13 and Steve Stem14, (1)Arizona State University, Tempe, AZ, United States, (2)Catholic University of America, Washington, DC, United States, (3)Planetary Science Institute, Tucson, AZ, United States, (4)AZ Space Technologies, Tempe, United States, (5)Radiation Monitoring Devices Inc., Auburn, MA, United States, (6)Arizona State University, Tempe, United States, (7)NASA, Moffett Field, CA, United States, (8)Qwaltec, Tempe, United States, (9)KinetX Inc, Tempe, AZ, United States, (10)Busek Co., Inc., Natick, United States, (11)Jet Propulsion Laboratory, Pasadena, CA, United States, (12)TechSource, Inc, Los Alamos, NM, United States, (13)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (14)Blue Canyon Technologies, Lafayette, CO, United States
Abstract:
The Lunar Polar Hydrogen Mapper (LunaH-Map) is a 6U CubeSat selected for flight on the Space Launch System (SLS) Artemis-1 mission through NASA's Science Mission Directorate under the Small, Innovative Missions for Planetary Exploration (SIMPLEx) program. Results from previous scientific missions to the Moon have identified the presence of water/frost within permanently shadowed regions (PSRs) at the poles, however, there remains uncertainty about the bulk (non-surficial/frost) abundance of these enrichments and whether these small-scale enrichments are pervasive throughout lunar south pole PSRs. Placing constraints on the bulk hydrogen abundance within PSRs will help point to specific processes and delivery sources for polar volatiles, and can help resolve mechanisms operating over long time scales (e.g. solar wind) from other, much shorter time scale delivery mechanisms (e.g. passing asteroids or comets). Identification of hydrogen enrichments at a spatial scale of ~15 km
2 could provide robust evidence for discerning hypotheses regarding transport processes of polar hydrogen emplacement and redistribution.
A number of technological developments are employed to enable this unique mission. The miniature neutron spectrometer (Mini-NS), capable of identifying small-scale (<15 km2) regions of hydrogen enrichments via the detection of lunar epithermal neutrons is both low power, and does not require precision pointing. The detector design is modular and allows for customization on future small mission architectures. In addition, the detector is sensitive to both neutrons and gamma-rays, which enables both mapping of hydrogen as well as some rock-forming elements (e.g. Si, Fe, Mg, Th, K). In order to achieve desired mission orbit with 10 to 15 km perilune above the South pole of the Moon, electric propulsion and a deployable articulated solar array are used. Communication with Earth will be achieved via the Iris radio, similar to that used on the MarCO spacecraft, albeit with a lower power output. A custom low mass structure is especially suited for housing all spacecraft components, maximizes radiator area, and accommodates the spacecraft harness. Mission-unique spacecraft software modules were also developed for this mission in order to minimize burn pointing errors and to unload reaction wheel momentum using the electric propulsion system.
