Search

• Human resources development aided the developing space program of the Philippines. • Most of the selected personnel for training came from the academia. • Trainees taken from the industry followed later to support the push for space. • Most of trained personnel opted to stay in the country to support the space program. The Philippines has experienced a shift of interest in space technology development and utilization over the past decade, culminating with the establishment of its national space agency in 2019. In cooperation with different universities in Japan, the Philippines successfully developed and launched two microsatellites, DIWATA-1 and DIWATA-2, and six nanosatellites, MAYA-1 to MAYA-6. By sending personnel to Japan and other space-faring countries, the country was able to rapidly ramp up its satellite development and utilization capabilities. In this paper, we examine and evaluate the complex human resources development efforts conducted by the country to support the creation of a local space ecosystem and ensure its long-term sustainability. Through a careful review, we identify how many people benefited from training programs, studies abroad or other forms of capacity building, and how these skilled individuals were retained in the budding Filipino space sector. Precisely, we looked at the backgrounds of the different people trained by the country, what type of training they received (funding, location, and duration), and how they are supporting the local space ecosystem at the time of writing this paper. [ABSTRACT FROM AUTHOR]

• This paper aims to explain the role of GEE in seismic anomalies detection. • Two recent powerful earthquakes in Japan (13 February and 20 March 2021) were discussed. • Time series of AOT, Chlorophyll and Ozone precursors deduced from GEE platform. • They were investigated using Median and LSTM methods. • Our satisfactory results show that we will see a significant leap forward in studies of earthquake precursors. Nowadays, satellite data is an appropriate and undeniable source for studying earthquake precursors due to their diversity, wide coverage, being up to date and low cost. Time series analysis of satellite data plays an important role in the process of detecting seismic anomalies in earthquake warning systems. But in order to reduce uncertainty during the seismic anomalies detection, it is necessary the use a variety of satellite data, although it leads to increase of data size and processing time. This paper aims to explain the role of Google Earth Engine (GEE) cloud platform in considerable progress of seismo-Lithospheric Atmospheric Ionospheric (LAI) anomalies detection in earthquake early warning systems. Among the different studied earthquakes, for example two recent powerful earthquakes in Japan (13 February and 20 March 2021) have been discussed. Deduced time series of three precursors (i.e. Aerosol Optical Thickness (AOT), Chlorophyll and Ozone) from GEE platform were investigated using Median method and a Long Short-Term Memory (LSTM) neural network to detect potentially seismo-LAI anomalies. Our satisfactory results show that with the addition of other various satellite data and also known predictors intelligent algorithms such as deep learning to GEE platform, we will see a significant leap forward in studies of earthquake precursors. [ABSTRACT FROM AUTHOR]

The Jupiter Icy Moons Explorer (JUICE) is a science mission led by the European Space Agency, being developed for launch in 2023. The Ganymede Laser Altimeter (GALA) is an instrument onboard JUICE, whose main scientific goals are to understand ice tectonics based on topographic data, the subsurface structure by measuring tidal response, and small-scale roughness and albedo of the surface. In addition, from the perspective of astrobiology, it is imperative to study the subsurface ocean scientifically. The development of GALA has proceeded through an international collaboration between Germany (the lead), Japan, Switzerland, and Spain. Within this framework, the Japanese team (GALA-J) is responsible for developing three receiver modules: the Backend Optics (BEO), the Focal Plane Assembly (FPA), and the Analog Electronics Module (AEM). Like the German team, GALA-J also developed software to simulate the performance of the entire GALA system (performance model). In July 2020, the Proto-Flight Models of BEO, FPA, and AEM were delivered from Japan to Germany. This paper presents an overview of JUICE/GALA and its scientific objectives and describes the instrumentation, mainly focusing on Japan's contribution. [ABSTRACT FROM AUTHOR]

The operational period of the first generation of dedicated Space VLBI (SVLBI) missions commenced in 1997 with the launch of the Japan-led mission VSOP/HALCA and is coming to closure in 2019 with the completion of in-flight operations of the Russia-led mission RadioAstron. They were preceded by the SVLBI demonstration experiment with the Tracking and Data Relay Satellite System (TDRSS) in 1986–1988. While the comprehensive lessons learned from the first demonstration experiment and two dedicated SVLBI missions are still awaiting thorough attention, several preliminary conclusions can be made. This paper addresses some issues of implementation of these missions as they progressed over four decades from the original SVLBI concepts to the operational status. [ABSTRACT FROM AUTHOR]

Abstract: This paper summarizes three micro-satellite impact tests completed in early 2007 through collaboration between Kyushu University and the NASA Orbital Debris Program Office. The previous experiments completed in late 2005 aimed to compare low- and hypervelocity impacts on identical target micro-satellites, whereas the new tests used larger micro-satellites as targets and aimed to investigate the effects of impact directions. Three identical micro-satellites equipped with fully functional electronic devices were prepared as targets. Their dimensions were 20cm by 20cm by 20cm, and the mass of each was approximately 1.3kg. Aluminum alloy solid spheres, with a diameter of 3cm and a mass of 39g, were prepared as projectiles. The impact velocity was approximately 1.7km/s. The impact tests were carried out using the two-stage light gas gun at the Kyushu Institute of Technology. All target micro-satellites were completely fragmented, but there were noticeable differences among the three sets of fragments due to the different impact directions. More than 1000 fragments from each test were collected, measured, photographed, and documented with material descriptions. Preliminary results of the new data and comparisons with the previous data will be presented in the paper. [Copyright &y& Elsevier]

Abstract: Missions to explore Europa have been imagined ever since the Voyager mission first suggested that Europa was geologically very young. Subsequently, the Galileo spacecraft supplied fascinating new insights into this satellite of Jupiter. Now, an international team is proposing a return to the Jupiter system and Europa with the Europa Jupiter System Mission (EJSM). Currently, NASA and ESA are designing two orbiters that would explore the Jovian system and then each would settle into orbit around one of Jupiter’s icy satellites, Europa and Ganymede. In addition, the Japanese Aerospace eXploration Agency (JAXA) is considering a Jupiter magnetospheric orbiter and the Russian Space Agency is investigating a Europa lander. The Jupiter Europa Orbiter (JEO) would be the NASA-led portion of the EJSM; JEO would address a very important subset of the complete EJSM science objectives and is designed to function alone or in conjunction with ESA’s Jupiter Ganymede Orbiter (JGO). The JEO mission concept uses a single orbiter flight system that would travel to Jupiter by means of a multiple-gravity-assist trajectory and then perform a multi-year study of Europa and the Jupiter system, including 30months of Jupiter system science and a comprehensive Europa orbit phase of 9months. The JEO mission would investigate various options for future surface landings. The JEO mission science objectives, as defined by the international EJSM Science Definition Team, include: [A.] Europa’s ocean: Characterize the extent of the ocean and its relation to the deeper interior. [B.] Europa’s ice shell: Characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface–ice–ocean exchange. [C.] Europa’s chemistry: Determine global surface compositions and chemistry, especially as related to habitability. [D.] Europa’s geology: Understand the formation of surface features, including sites of recent or current activity, and identify and characterize candidate sites for future in situ exploration. [E.] Jupiter system: Understand Europa in the context of the Jupiter system. The JEO orbital mission would provide critical measurements to support the scientific and technical selection of future landed options. The primary challenge of a Europa mission is to perform in Jupiter’s radiation environment, radiation damage being the life-limiting parameter for the flight system. Instilling a system-level radiation-hardened-by-design approach very early in the mission concept would mitigate the pervasive mission and system-level impacts (including trajectory, configuration, fault protection, operational scenarios, and circuit design) that can otherwise result in runaway growth of cost and mass. This paper addresses the JEO mission concept developed by a joint team from JPL and the Applied Physics Laboratory to address the science objectives defined by an international science definition team formed in 2008, while designing for the Jupiter environment. [Copyright &y& Elsevier]

Abstract: In this paper a model for computing geomagnetically induced currents (GIC) from local geomagnetic field observations carried out in Hokkaido, Japan is constructed. The model is composed of system parameters mapping the horizontal geoelectric field to GIC and of 1D conductivity model. A rigorous model validation is used to show that the model reproduces the observed GIC with a very good accuracy. Statistical occurrence of GIC is computed using the constructed model and geomagnetic field recordings covering years 1986–2008. The modeled GIC is used to generate a list of 10 largest GIC events in Hokkaido, Japan. It is found that the 10 largest events between 1986 and 2008 were associated with various phases of coronal mass ejection driven major geomagnetic storms. It is also shown that although smaller GIC are fairly common, the largest possible GIC are likely limited to the amplitudes of the order of 10A. The constructed 1D ground conductivity model is interpreted in the context of the local geological setting and it is shown that the subduction zone dynamics likely play an important role in the observed GIC and geomagnetic field characteristics. Crustal conductor associated with the subduction zone is the cause for unusual direct relation between GIC and the local geomagnetic field rather than its time derivative and GIC. [Copyright &y& Elsevier]

Abstract: Japan Aerospace Exploration Agency (JAXA) has proposed an active debris removal using electro-dynamic tether to reduce large space debris in the low-Earth orbit. However, a tether strand is thin but long enough to have a large area so that it is vulnerable to small particles. This vulnerability might be the weakest point of a tether system against orbital debris. In order to overcome this weakest point, a double tether system, in which two tether strands are tied together at even intervals to form equally spaced loops, has been suggested as one of the promising candidates. This paper provides a mathematical approach to estimate the survival probability of a double tether system and then apply the approach to evaluate the mission success rate of the active debris removal using electro-dynamic tether that JAXA has proposed. It can be concluded the countermeasure to get enough success rate can be obtained. The result is simulated for Advanced Earth Observing Satellite II (ADEOS-II) re-entry from 800km sun synchronized orbit to atmosphere. The simulation shows that mission success rate over 90% can be obtained with number of loops over 1000 and 10mm clearance between two strands. [Copyright &y& Elsevier]

Abstract: PHITS (Particle and Heavy-Ion Transport code System) is a general-purpose three-dimensional Monte Carlo code, developed and maintained by RIST, JAEA and KEK in Japan together with Sihver et al. at Chalmers in Sweden. PHITS can deal with the transports of all varieties of hadrons and heavy ions with energies up to around 100GeV/nucleon, and in this paper the current status of PHITS is presented. We introduce a relativistically covariant version of JQMD, called R-JQMD, that features an improved ground state initialization algorithm, and we will present the introduction of electron and photon transport in PHITS using EGS5, which have increased the energy region for the photon and energy transport from up to around 3GeV to up to several hundred GeV depending on the atomic number of the target. We show how the accuracy in dose and fluence calculations can be improved by using tabulated cross sections. Benchmarking of shielding and irradiation effects of high energy protons in different materials relevant for shielding of accelerator facilities is also presented. In particular, we show that PHITS can be used for estimating the dose received by aircrews and personnel in space. In recent years, many countries have issued regulations or recommendations to set annual dose limitations for aircrews. Since estimation of cosmic-ray spectra in the atmosphere is an essential issue for the evaluation of aviation doses, we have calculated these spectra using PHITS. The accuracy of the atmospheric propagation simulation of cosmic-ray performed by PHITS has been well verified by experimental cosmic-ray spectra taken under various conditions. Based on a comprehensive analysis of the simulation results, an analytical model called “PARMA” has been proposed for instantaneously estimating the atmospheric cosmic-ray spectra below the altitude of 20km. We have also performed preliminary simulations of long-term dose distribution measurements at the ISS performed with the joint ESA-FSA experiment MATROSHKA-R (MTR-R) led by the Russian Federation Institute of Biomedical Problems (IMBP) and the ESA supported experiment MATROSHKA (MTR), led by the German Aerospace Center (DLR). For the purpose of examining the applicability of PHITS to the shielding design in space, the absorbed doses in a tissue equivalent water phantom inside an imaginary space vessel has been estimated for different shielding materials of different thicknesses. The results confirm previous results which indicate that PHITS is a suitable tool when performing shielding design studies of spacecrafts. [Copyright &y& Elsevier]

Abstract: Progress in information technology has enabled to collecting data in near real-time. This significantly improves our ability to monitor space weather conditions. We deliver information on near real-time space weather conditions via the internet. We have started two collaborations with space weather users. One is a measurement of geomagnetically induced current (GIC) of power grids in collaboration with a Japanese power company. The other concerns radiation hazards for aircrews. The radiation exposure level for aircrews was been determined by the Japanese government by the end of 2005. The proposed upper limit is 5mSV a year. We are actively seeking ways to contribute to this subject. Our activities at the Japanese space weather center are reported in this paper. [Copyright &y& Elsevier]

The Institute of Space and Astronautical Science (ISAS) of Japan plans to contribute the Mercury Magnetospheric Orbiter (MMO) to the BepiColombo program, the ESA Cornerstone mission to the planet Mercury. The principal objective of the MMO is to study the magnetic field and magnetosphere of Mercury. The ISAS Mercury exploration working group has performed the definition study of the MMO mission in cooperation with the ESA/ESTEC BepiColombo project team. This paper briefly reviews the scientific objectives, and describes the model payload and its operation plan. [Copyright &y& Elsevier]