The Lunar Environment Monitoring Station (LEMS)

<p>The Lunar Environment Monitoring Station (LEMS) is an instrument concept funded by NASA’s Development of Advanced Lunar Instrumentation (DALI) Program, and undergoing maturation at NASA's Goddard Space Flight Center. LEMS has been proposed to the NASA's recent call for Payloads and Research Investigations on the Surface of the Moon (PRISM).</p><p>LEMS is a compact, autonomous, self-sustaining and long-lasting instrument suite that enables in situ, continuous, long-term monitoring of the lunar exosphere and of the most relevant natural and manmade controlling processes (infall of interplanetary dust particles (IDP), influx of solar wind and magnetospheric particles, EUV irradiation, interior outgassing, disturbances by landers and human surface activities). LEMS can be delivered to the surface of the Moon by crewed or robotic missions. Once deployed (on a deck or directly on the surface), LEMS will operate day and night for a nominal duration of 2 years without requiring any additional support or resources from the carrying asset.</p><p>LEMS integrates a Mass Spectrometer, a Laser Retro-reflector Array, a Lunar Micrometeoroid Monitor, a Lunar Energetic Ion Analyzer, and a 3-axis Seismometer. These sensors will collect concurrent observations that will lead to a comprehensive, time-resolved, and geographically-localized characterization of the composition and dynamics of volatiles gases in the lunar exosphere as a response to variations in solar forcing, IDP flux, seismicity, and known manmade events. Furthermore, owing to its expected longevity, LEMS will also improve upon the success of the Apollo Passive Seismic Experiment (PSE) by providing a new generation of seismological measurements that will address unanswered questions by the PSEs. These questions include the size and state of the lunar core, homogeneity of the mantle, variation in crustal thickness, the mechanism for deep moonquakes, and the relationship between shallow seismicity and the current tectonic state of the lunar crust.</p><p>With its complementary and integrated multi-sensors and its autonomous concept of operation, LEMS is a science-enabling investigation that combines capabilities, in a single duplicable instrument package. The duplicative nature of the LEMS design enables a network of stations that focuses on exospheric and geophysical measurements at the Moon to become viable options. Finally, the self-sustaining architecture of LEMS provides a model design of future payloads that can take advantage of more commercial or scientific flight opportunities to the Moon while requiring no further support for operation from their carrying assets.</p>

Ion Cyclotron Waves on Lunar Surface: Apollo Observations and Implications for Future Lunar Missions

<p>Our previous study of the restored Apollo Lunar Surface Magnetometer (LSM) data discovered that narrowband ion cyclotron waves were often observed at the Apollo 15 and 16 landing sites when the Moon was in the Earth’s magnetotail (Chi et al., 2013). Two mechanisms have been proposed to explain the excitation of ion cyclotron waves at the Moon: the absorption of ions at the lunar surface and the pickup ions from the lunar exosphere. Either process can lead to an ion velocity distribution unstable to ion cyclotron instability, but it is of particular interest to investigate which ion cyclotron waves are associated with the latter mechanism so that the observations of them can provide hints to the type and the number of pickup ions escaped from the lunar exosphere. More recently, Nakagawa et al. (2018) examined the Kaguya data and found similar ion cyclotron waves in the Earth’s magnetotail but at a very low occurrence rate.</p><p>In this study, we perform statistical analysis on the full set of the restored LSM data, including those from the Apollo 12, 15, and 16 missions between 1969 and 1975, that were only partially available to our previous study. We find that the ion cyclotron waves were observed by Apollo 15 LSM approximately 5% of the time, which is about six times more frequently than that found in Kaguya observations. A slightly lower occurrence rate of ion cyclotron waves is found in the Apollo 16 LSM data because of the strong local crustal magnetic field at the Apollo 16 site and the conservation of the Poynting flux. Future joint measurements by lunar landers and orbiters can enable a true comparison of the ion cyclotron waves on the lunar surface and at different altitudes of the exosphere.</p>

Compact High Resolution QIT-Mass Spectrometers for Lunar and Planetary Applications

<p>The JPL Mass Spectrometer Team develops components and instruments based on a Paul quadrupole ion trap mass spectrometer (QIT-MS) for Earth and space applications. Over the past 20 years, the team has miniaturized the QIT-MS and verified its performance successfully for the International Space Station. The technology was demonstrated with the recent delivery of the first Spacecraft Atmosphere Monitor (S.A.M.) to the International Space Station (ISS).</p><p>The next step is to build a QIT-MS intendent to investigate the lunar exosphere via a funded ROSES 2019, DALI/NASA proposal over the next three years.</p><p>The QIT-MS will be the first in-situ lunar mass spectrometer capable of identifying and quantifying exosphere species (ex. H, H2, 3He, 4He, Ne, N2, O2, Ar, CH4, CO, CO2, Kr, Xe, OH, H2O) with abundance greater than 10 molecules/cm3 [1]. The combination of low mass (7.5 kg), low power (max. 30W with heater bulb on), high sensitivity (0.003 counts/cm3/sec), and ultrahigh precision (1.7 x 10<sup>-10</sup> Torr, Kr measured continuously for 7 hours yielded a 0.6 ‰ precision on the 86Kr/84Kr ratio) will provide an unpreceded inside of the scientific processes in the lunar exosphere.</p><p>Other implementation approaches will be discussed, which entail the development of different frontends to expand applications for dense atmospheres (ex. Venus) or liquids (ex. ocean worlds). Most of these developments can be used to determine contaminants in the air, water, or volatile in solids.</p><p>[1] G. Avice, A. Belousov, K. A. Farley, S. M. Madzunkov, J. Simcic, D. Nikolic, M. R. Darrach and C. Sotin, “High-precision measurements of krypton and xenon isotopes with a new static-mode quadrupole ion trap mass spectrometer,” JAAS, Vol 34, January 2019</p><p> </p><p>Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109</p><p> </p>