Mechanism for assembling antenna in space

The development of large and precise space antennas is one of the most important topics in constructing space infrastructures. We evaluated an approach to assembling large and accurate space antennas which uses space robots. The assembly mechanism was launched together with the ETS-VII, the first telerobotic satellite from Japan, and its performance, including fully automatic assembling, was verified. The assembling-type antenna and the results of antenna assembly experiments are discussed     

ETS-II Experiments Part II: Earth Station Facilities

A part of the Earth station at the Kashima Branch of the Radio Research Laboratories has a highly sensitive receiving system newly designed for receiving 3 coherent and weak beacon signals transmitted from the Engineering Test Satellite Type-II (ETS-II) of Japan and obtaining propagation data on quasimillimeter and millimeter wavelengths. The ground system includes a main receiving station which has a 10-m diameter antenna for multifrequencies, highly sensitive receivers, a rain radar, which has many unique functions, a radiometer, meteorological instruments, and data processing computers. The facilities of the main receiving station for ETS-II propagation experiments, except for the rain radar, are described.     

Communications and radio determination system using twogeostationary satellites. I. System and experiments

We developed two types of hybrid terminals that can provide both satellite communication and position determination services in one system. One terminal uses the single channel per carrier (SCPC) technique and the other uses the spread spectrum (SS) technique. To evaluate the performance of the two systems, we carried out experiments in Japan and in the Pacific Ocean using two geostationary satellites, ETS-V (150°E) and Inmarsat (180°E). The ranging accuracy between the mobile terminals and the base station via the satellites was found to be about 200 m using the SCPC system and about 10 m using the SS system. The measured positioning accuracy was about 1 km in the SCPC system and about 600 m in the SS system when experiments were carried out near Japan. The experimental results show that the positioning errors were mainly caused by the orbital determination errors of the two satellites. Presented here are the configurations and features of the SCPC and SS terminals, the experimental system, and the experimental results     

庄河、光明山陨石的岩石矿物学研究

庄河陨石和光明山陨石是两个降落于同一地区的Ｈ５型普通球粒陨石．根据两辉石温度计求出这两个陨石的平衡温度＜ ５００℃；根据镍纹石的带宽与组成关系，获得光明山陨石在其母体中的冷却速率约为 １０－１０℃／Ｍａ，而庄河陨石中普遍出现均一的四方镍纹石表明其冷却速率更低．光明山陨石的冲击变质特征以硅酸盐颗粒破碎为主，其冲击相为Ｓ１；庄河陨石中硅酸盐矿物具明显的波状消光，并存在细小的冲击熔融脉，其冲击相划分为Ｓ２．     

Mercury Dust Monitor (MDM) Onboard the Mio Orbiter of the BepiColombo Mission

Space Science Reviews - In this chapter, we review the contribution of space missions to the determination of the elemental and isotopic composition of Earth, Moon and the terrestrial planets, with...     

Analytical expression for distant retrograde orbits around a small natural satellite

An analytical expression for distant retrograde orbits (DROs) is obtained in this study. Owing to the fact that a planar DRO is a closed orbit and can be expressed as an approximately elliptical orbit, respective geometries and periods of DROs are analytically calculated. A switching point, where various properties of planar DROs change abruptly with an increase in the orbital radius, is determined. The Mars–Deimos system is taken as a case study in this work. The proposed method can be applied to cases where the Hill’s approximation of the restricted three-body problem is valid. Numerical calculations are performed to validate the proposed method.     

Structure and NIR feature of QCC: a laboratory analog of carbon dust.

We have produced thin films of quenched carbonaceous composite (QCC) by hydrocarbon plasma deposition. The effect of thermal annealing on QCC has been investigated to understand how QCC, as a laboratory analog of carbon dust, is transformed in the warm environment around evolved stars. Spectroscopic measurements have indicated that, by heating, the proportion of aromatic sp2 CH bonds increases relative to sp3 CH bonds. Carbon onion-like spherules of approximately 10 nm in diameter are found with electron microscopic images after "graphitization" of thermal annealing.     

Structure and UV absorption of QCCs: carbonaceous dust analogues.

"Quenched Carbonaceous Composites (QCCs)" are carbonaceous interstellar dust analogues synthesized in the laboratory from a hydrocarbon plasma. We produced new types of carbonaceous condensates from the ejecta of plasma with mixtures of methane and hydrogen as source gases. We find that QCC with an absorbance peak at 220 nm is composed of onion-like spherules, and QCCs with an absorbance peak at 230-240 nm are composed of polyhedral particles. The onion-like QCC contains aromatic hydrogen bonds, and it shows the 3.3 and 11.4 micrometers absorption bands. The QCC with an absorbance peak at 230-240 nm is composed of ribbons with bent graphitic layers. This suggests that the carrier of the interstellar 220 nm extinction band might also be an emitter of the interstellar diffuse emission bands.     

Jikiken(EXOS-B) observation of siple transmissions

A Japanese magnetospheric satellite Jikiken (EXOS-B) was used to observe Siple transmissions and VLF emissions triggered by the Siple signals. Energetic particle fluxes were also observed at the same time. The first experiments were made during July, August and September in 1979 and the second experiments were made during December in 1979 and January in 1980. The Siple triggered emissions were observed in August. This report reviews the preliminary results.     

Whistler mode propagation in the earth and planetary magnetospheres and ray tracing techniques

Whistler mode wave phenomena observed in the earth's environment and in the planetary magnetospheres, such as in the vicinity of the Jupiter, Venus, and Saturn are reviewed, Importance of ray tracing technique is stated in connection with the interpretation of these phenomena. A historical review of ray tracing technique is then given. Finally the most recent ray tracing technique, such as 3-D ray tracing in a non-dipolar background magnetic field model is introduced.