Calibration of Mars Energetic Particle Analyzer (MEPA)

Tang, S.W.; Wang, Yi; Zhao, Hong-yun; Fang, Fang; Qian, Yi; Yongjie, Zhang; Yang, Haibo; Li, Cunhui; Fu, Qiang; Kong, Jie; Hu, Xiangyu; Su, Hong; Sun, Z.; Yu, Yuhong; Zhang, Baoming; Sun, Y.; Sun, Zhe

doi:10.26464/epp2020055

Cited by 14 publications

(9 citation statements)

References 12 publications

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“…We also compared the RAD cruise-phase measurement to that of Liulin-MO on TGO results (Semkova et al 2018) of the cruise journey in 2016, which are in agreement considering the different levels of solar modulation in 2012 and 2016. At the time of writing, another instrument MEPA (Tang et al 2020) on board the Chinese Mars Tianwen-1 mission is cruising towards Mars. Both Liulin-MO and MEPA monitor the orbiter radiation environment of Mars and can be used synergistically with RAD to assess the global radiation at Mars at different spatial and temporal scales.…”

Section: Discussionmentioning

confidence: 99%

Radiation environment for future human exploration on the surface of Mars: the current understanding based on MSL/RAD dose measurements

Guo

Zeitlin

Wimmer‐Schweingruber

et al. 2021

Astron Astrophys Rev

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Potential deleterious health effects to astronauts induced by space radiation is one of the most important long-term risks for human space missions, especially future planetary missions to Mars which require a return-trip duration of about 3 years with current propulsion technology. In preparation for future human exploration, the Radiation Assessment Detector (RAD) was designed to detect and analyze the most biologically hazardous energetic particle radiation on the Martian surface as part of the Mars Science Laboratory (MSL) mission. RAD has measured the deep space radiation field within the spacecraft during the cruise to Mars and the cosmic ray induced energetic particle radiation on Mars since Curiosity’s landing in August 2012. These first-ever surface radiation data have been continuously providing a unique and direct assessment of the radiation environment on Mars. We analyze the temporal variation of the Galactic Cosmic Ray (GCR) radiation and the observed Solar Energetic Particle (SEP) events measured by RAD from the launch of MSL until December 2020, i.e., from the pre-maximum of solar cycle 24 throughout its solar minimum until the initial year of Cycle 25. Over the long term, the Mars’s surface GCR radiation increased by about 50% due to the declining solar activity and the weakening heliospheric magnetic field. At different time scales in a shorter term, RAD also detected dynamic variations in the radiation field on Mars. We present and quantify the temporal changes of the radiation field which are mainly caused by: (a) heliospheric influences which include both temporary impacts by solar transients and the long-term solar cycle evolution, (b) atmospheric changes which include the Martian daily thermal tide and seasonal CO$$_2$$ 2 cycle as well as the altitude change of the rover, (c) topographical changes along the rover path-way causing addition structural shielding and finally (d) solar particle events which occur sporadically and may significantly enhance the radiation within a short time period. Quantification of the variation allows the estimation of the accumulated radiation for a return trip to the surface of Mars under various conditions. The accumulated GCR dose equivalent, via a Hohmann transfer, is about $$0.65 \pm 0.24$$ 0.65 ± 0.24 sievert and $$1.59 \pm 0.12$$ 1.59 ± 0.12 sievert during solar maximum and minimum periods, respectively. The shielding of the GCR radiation by heliospheric magnetic fields during solar maximum periods is rather efficient in reducing the total GCR-induced radiation for a Mars mission, by more than 50%. However, further contributions by SEPs must also be taken into account. In the future, with advanced nuclear thrusters via a fast transfer, we estimate that the total GCR dose equivalent can be reduced to about 0.2 sievert and 0.5 sievert during solar maximum and minimum periods respectively. In addition, we also examined factors which may further reduce the radiation dose in space and on Mars and discuss the many uncertainties in the interpreting the biological effect based on the current measurement.

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Section: Discussionmentioning

confidence: 99%

Radiation environment for future human exploration on the surface of Mars: the current understanding based on MSL/RAD dose measurements

Guo

Zeitlin

Wimmer‐Schweingruber

et al. 2021

Astron Astrophys Rev

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“…Therefore, continuous observations monitoring the energetic particles arriving at Mars would be of great benefit for future accurate forecast of the SEP‐induced radiation on Mars. Currently, the Mars Energetic Particle Analyzer (MEPA, Tang et al., 2020) on board the first Chinese Mars exploration mission (Tianwen‐1) has been monitoring the flux of particles with energy between 2 and 100 MeV at Mars orbit since February 2021. This energy range complements that by the SEP instrument of Mars Atmosphere and Volatile EvolutioN (MAVEN, Larson et al., 2015) orbiter which measures the flux of particles with energy lower than about 13 MeV.…”

Section: Discussionmentioning

confidence: 99%

What Is the Radiation Impact of Extreme Solar Energetic Particle Events on Mars?

2023

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Solar Energetic Particles (SEP) are one of the major sources of the Martian radiation environment. It is important to understand the SEP‐induced Martian radiation environment for future human habitats on Mars. Due to the lack of a global intrinsic magnetic field, Solar Energetic Particles (SEPs) can directly propagate through and interact with its atmosphere before reaching the surface and subsurface of Mars. Mars has many high mountains and low‐altitude craters where the atmospheric thickness can be more than 10 times different than one another. The SEP‐induced surface radiation level may therefore be very different from one location to another. We thus consider the influence of the atmospheric depths on the Martian radiation levels including the absorbed dose, dose equivalent, and (human‐)body effective dose induced by SEPs at varying heights above and below the Martian surface. The state‐of‐the‐art Atmospheric Radiation Interaction Simulator based on GEometry And Tracking Monte‐Carlo method has been employed for simulating particle interactions with the Martian atmosphere and terrain. We find that even the thinnest Martian atmosphere reduces radiation dose from that in deep space by at least 65%, and the shielding effect increases for denser atmosphere. Furthermore, we present a method to quickly forecast the SEP‐induced radiation in different regions of Mars with different surface pressures.

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“…The processing procedures of each instrument are given in Table 3. The more detailed information about calibration is published in the overview of each instrument (Tang et al 2020;Yu et al 2020;Kong et al 2020;Liang et al 2021;Meng et al 2021;Fan et al 2021;He et al 2021;Du et al 2020;Peng et al 2020;Zhou et al 2020).…”

Section: Data Calibration (Level 2a Processing)mentioning

confidence: 99%

Design and Validation of the Scientific Data Products for China’s Tianwen-1 Mission

Zhang

et al. 2021

Space Sci Rev

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The Tianwen-1 mission is China’s first Mars exploration mission. To complete the scientific objectives of “orbiting, landing, and patrolling” in one mission, thirteen instruments for acquiring multi-disciplinary data are configured. The data products with rich ancillary data and flexible structures will facilitate the data application. To integrate the requirements of experts from disparate disciplines and leverage new information technologies, a complete redesign of data products is promoted in the Tianwen-1 mission. We discuss the whole process of data product generation from the data pipeline design to data validation. We design the various data products according to the application requirements of each data type, including radar echo data, spectrum data, image data, energy spectrum data, magnetic field data, meteorological data, and acoustic data. Since various error sources will exist in the generation chain of the data products, data validation is essential before release to the public; the validation activities are discussed at the end. We deliver these scientific products to the community in a timely manner, with ancillary information and quality information. This paper can provide practical reference for Tianwen-1 data application.

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Calibration of Mars Energetic Particle Analyzer (MEPA)

Cited by 14 publications

References 12 publications

Radiation environment for future human exploration on the surface of Mars: the current understanding based on MSL/RAD dose measurements

Radiation environment for future human exploration on the surface of Mars: the current understanding based on MSL/RAD dose measurements

What Is the Radiation Impact of Extreme Solar Energetic Particle Events on Mars?

Design and Validation of the Scientific Data Products for China’s Tianwen-1 Mission

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