Japan Geoscience Union Meeting 2024

Presentation information

[J] Oral

P (Space and Planetary Sciences ) » P-PS Planetary Sciences

[P-PS07] Planetary Sciences

Thu. May 30, 2024 3:30 PM - 4:45 PM 102 (International Conference Hall, Makuhari Messe)

convener:Sota Arakawa(Japan Agency for Marine-Earth Science and Technology), Haruhisa Tabata(Department of Earth and Planetary Science, University of Tokyo), Ryosuke Tominaga(School of Science, Department of Earth and Planetary Sciences, Tokyo Institute of Technology), Chairperson:Haruhisa Tabata(Department of Earth and Planetary Science, University of Tokyo), Ryosuke Tominaga(Star and Planet Formation Laboratory, RIKEN Cluster for Pioneering Research), Sota Arakawa(Japan Agency for Marine-Earth Science and Technology)

3:45 PM - 4:00 PM

[PPS07-02] Consideration of Long-Term Observation for Penetrator Using Solar Power Generation

*Kodai Yamamoto1, Yasuhiro Nishikawa1, Masa-yuki Yamamoto1, Satoshi Tanaka2, Kazuto Saiki3 (1.Kochi University of Technology, 2.Japan Aerospace Exploration Agency, 3.Ritsumeikan University)

Keywords:Penetrator, Antarctic Region, Solar Power Generation

The penetrator, a probe utilizing the hard-landing method, has advantages such as the ability to easily install observation equipment in hard-to-reach areas (Unmanned-Place) and a lower risk of installation compared to complex soft-landing systems. Some of the authors participated in the 64th Japan Antarctic Research Expedition (JARE64) and conducted observations using penetrators. The current penetrator observation system used primary batteries, which have the problem of inability to conduct long-term observations. To address this issue and be enable long-term observations with penetrators, especially in the Antarctic region, authors selected it as a study case, considered solar power generation, and aimed to perform a quantitative evaluation of the extending of observation period. Penetrators can create observation station by being deployed from the sky using drones and other flying devices. However, due to its unique installation method, maintenance of the system, such as battery replacement, is not possible. Therefore, there is a need to quantify the solar radiation required for solar power generation through numerical calculations. Accordingly, a theoretical formula (Equation (1)) was constructed based on of Murai et al[1]., solar radiation calculation formula.
J = f(omega,t,delta,theta,phi,P0,C,)...(1)
In Equation (1), the variable omega represents latitude, t is the solar hour angle, delta denotes the solar declination, theta is the panel azimuth angle, phi is the panel tilt angle,P0 is the atmospheric transmittance coefficient,and C is the loss coefficient of solar radiation due to weather conditions.If the validity of Equation(1) is demonstrated, it becomes possible to calculate the solar radiation at any points on a planet that revolves around the sun while also rotating. To verify the validity of Equation(1), solar radiation data at Sapporo, Tokyo, Kochi, and Antarctica (Showa Base) were compared with the meteorological agency's observational datasets.As a result, the relative error was generally within 10%, leading to the conclusion that numerical calculations using Equation(1) are appropriate. Additionally, we conducted calculations taking reflection into account based on the report that the power generation can reach a maximum of 2.2 times due to reflected light, as confirmed by Aoki et al[2].,Based on the calculations considering these factors, we performed a transition calculation of the power capacity for penetrators. For instance, by fixing the panel tilt angle at 90 degrees, the capacity of the secondary battery (BT) at 72 Ah, the power consumption (PLOSS) at 1.23 Ah/Day, and varying the solar panel size (S) among 2, 3, and 4 m2, the transition of power capacity was calculated. It was found that the observation period of the penetrator is continuous (BT > 0) when S = 4 m2, but for size below that, in polar region, there are days during the polar night period when the power capacity is depleted. The results of numerical calculations suggest that the observation period depends on solar panel size, power consumption, and power capacity. This implies the possibility of reducing the solar panel area to be realistic conditions, becoming a crucial factor in determining the specifications of the penetrator in the future.
[1]Shunji Murai, "A BASIC STUDY ON THE EFFECTS OF THE SUN BEAM AND ITS ENERGY", Proceedings of the Japan Society of Civil Engineers, vol. 1973, no. 215, pp.49-59, In Japanese, 1973.
[2]Hidetoshi AOKI , Nakao HIROTA, "The Effect of Radiation Reflected from Snow Surfaces on the Generated Energy of Photovoltaic Modules", The bulletin of Laboratory for Energy, Environment and Systems, Hachinohe Institute of Technology, vol. 10, pp. 29-34,In Japanese, 2012.