Yongchun Zheng

In-Situ Water Production by Reducing Ilmenite

Water is considered to be a fundamental condition of human’s colonization of the moon. The supply of oxygen is essential to the utilization of most lunar resources. According to the result of rough calculation, the cost for delivering oxygen from earth to moon for a ten-people lunar base will be nearly 5 to 9 billion dollars a year (Schrunk 1999; Taylor and Carrier 1993; Duke 2003). The cost is so high that water cannot be entirely supported by transportation from the Earth. Nevertheless, there are considerable mineral reserves in lunar soil. Compared to transporting water from earth directly, it is more economical to extract it from the lunar soil. The effects of meteorites, solar wind and cosmic ray make most of the lunar surface covered with a layer of lunar soil. The thickness of lunar soil is approximately 4~5 meters at the mare and >10 meters on the highland. The only practical source of water in the lunar soil is igneous minerals which contain typically 40 to 50% oxygen as oxides. The major minerals are ilmenite, anorthite, and olivine. All these oxides can provide oxygen and water to the lunar base even though some of them cannot be easily reduced. Compared with oxides of silicon, aluminum, titanium, calcium or magnesium, it is much more easily to extract oxygen from iron oxide such as ilmenite.

The effects of spacecraft charging and outgassing on the LADEE ion measurements

Abnormal ion signals can be usually seen in the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission, including a suddenly enhanced current observed by the Lunar Dust Experiment (LDEX) near the sunlight-shadow boundary and an unexpected water ion measured by the Neutral Mass Spectrometer (NMS), with their magnitudes insensitive to the convection electric field of solar wind (SW) but dependent on the SW density and the elapsed time of LADEE mission. By analyzing both the LDEX measurements and the NMS measurements, we find that the current enhancement can be caused by a negatively charged spacecraft in the shadow region while the significant water ions should be some artificial ions from spacecraft outgassing. The artificial water ions show a peak near 8:00 LT that may be related to a sunlight-controlled surface outgassing. In addition, the H2O flux can be enhanced near the end of the mission when the spacecraft has a lower altitude. It is found that the H2O enhancement is actually caused by an exosphere-contributed return flux, rather than a real water exosphere.

Submicroscopic metallic iron in lunar soils estimated from the in situ spectra of the Chang'E-3 mission: First In Situ Estimates of SMFE in Lunar Soils

…This research was supported by the National High Technology Research and Development Program of China (863 Program: 2015AA123704), the National Natural Science Foundation of China (41422110 and 41490633), the Science and Technology Development Fund of Macau (020/2014/A1), and Minor Planet Foundation of Purple Mountain Observatory. The contribution of D.T.B. was made possible by the Chinese Academy of Sciences President’s International Fellowship Initiative, grant 2015VEB057 and by NASA Lunar Data Analysis Program grant NNX16AN55G. E.A.C. thanks NSERC and the Canadian Space Agency for supporting this study.

Mapping and compositional analysis of mare basalts in the Aristarchus region of the Moon using Clementine data

The process of accurately defining and outlining mare basalt units is necessary for constraining the stratigraphy and ages of basalt units, which are used to determine the duration and the flux of lunar volcanism. We use a combination of Clementine’s five-band ultraviolet/visible data and TiO 2 and FeO abundance distribution maps to define homogenous mare basalt units and characterize their compositional variations (with maturity) in the Aristarchus region. With 20 groups of distinct mare basaltic soils identified using the method in this paper, six additional spectrally defined areas and five basaltic units are constructed, and their mineralogic quantization values provide new constraints on their temporal and spatial evolution. Our results indicate that the Aristarchus region has diverse basalt units and a complex history of volcanic evolution. We also demonstrate that the techniques, from which spectrally distinct mare basalts can be mapped, performed well in this study and can be confidently expanded to other mare regions of the Moon.

Mineral surface modification induced by low energy ion irradiation: Implications for solar-wind exposure effects in lunar soil

We performed ion irradiation on olivine and ilmenite to simulate solar-wind exposure effects in lunar soil. The surface morphology and microstructure after ion irradiation were characterized by field emission scanning electron microscopy. Sputtering erosion significantly modified the surface of irradiated Luobusha olivine grains. All irradiated grains show smooth surface and round shape. The cleavage fractures on the unirradiated olivine surface were widened and deeply etched after He+ irradiation. Both of these are the consequence of ion sputtering erosion. There are no bubbles or voids foundin the irradiated olivine grains, because He+ dose in this study is lower than saturated fluence. Irradiated Panzhihua ilmenite grains are all covered with smooth flakes with the thickness of about 400 nm. The formation of the flakes should be related with helium bubbles and their growth during He+ implantation. Some columnar-shaped particles are found at the surface of irradiated Panzhihua ilmenite. We speculate that these particles should be sulfide because of significantly high sulfur contents.

Research on the inversion of elemental abundances from Chang＇E-2 X-ray spectrometry data

The elemental abundances of lunar surface are the important clues to study the formation and evolution history of the Moon. In 2010, China’s Chang’E-2 (CE-2) lunar orbiter carried a set of X-ray spectrometer (XRS) to investigate the elemental abundances of the lunar surface. During CE-2’s life span around the Moon, the XRS experienced several events of solar flare. The X-ray solar monitor onboard recorded the spectra of solar X-rays at the same time. In this paper, we introduced the XRS instrument and data product. We analyzed the characteristics of the XRS data. Using the data obtained during an M solar flare event which had occurred on Feb. 16, 2011, we derived the elemental abundances of Mg, Al, Si, Ca and Fe of the lunar surface in the Oceanus Procellarum. Finally, we discussed the factors that influence the accuracy of the inversion.

Condition of Solar Radiation on the Moon

Solar radiation is an exterior heat source of the Moon and represents a key resource with respect to returning to the Moon. It controls the variation of lunar-surface temperature during the lunation, and changes the thermal radiation properties of the lunar surface. In lunar Earth-based exploration, orbital exploration, and manned and unmanned lunar surface activities, solar radiation is an important factor which should be considered.