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.     

Identification of power analysis models for ETS-III operation

This paper describes the identification of power analysis models of BOP (the Bus Equipment Operation Analysis Program) for ETS-III operation. The ETS-III (Engineering Test Satellite III) was launched in September 1982. BOP simulations are to provide prior confirmation for safe operation in terms of electrical power and thermal control situations. It is necessary to identify power analysis model first and improve the model for higher accuracy. Studies for model identification have been done by using flight data and simulation results. As a result of these studies, the power analysis model meets well with the actual ETS-III power situation and the aimed accuracy of the model has been achieved.     

Attitude dynamics of a pendulum-shaped charged satellite

In this paper, we investigate the possibility of the use of the Lorentz force, which acts on charged satellite when it is moving through the magnetic field, as a means of satellite attitude control. We first derive the equations of attitude motion of charged satellite and then investigate the stability of the motion. Finally we propose an attitude control method using the Lorentz force. Our method requires moderate charge level for future Lorentz-augmented satellite.     

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.     

Visual analysis in a deployable antenna experiment [satellite antenna]

To establish a large deployable antenna, monitoring and collimation are essential for reliable and precise deployment. We have developed an analysis method to detect shifts in several images, in which the combination of cross-correlations between images and approximations at subpixel precision enables us to detect shifts in images with a precision of up to 0.01 pixels. The LDREX mission; which was a preliminary experiment for a large deployable antenna, ETS-VIII, was performed in December 2000. During this experiment, anomalies occurred in the antenna, and deployment was aborted. To understand the cause of the anomalies, we used our visual analysis method. Using this analysis, we detected vibrating features in the antenna, which were useful for explaining the anomalies. We outline our visual analysis method and discuss its application in monitoring the deployable antenna.     

Current status of the BepiColombo/MMO spacecraft design

This paper shows the current baseline of the conceptual design of the BepiColombo/MMO (mercury magnetospheric orbiter) spacecraft, which is conducted by the ISAS Mercury Exploration Working Group. The MMO is a spinning spacecraft of 200 kg mass whose spin axis is nearly perpendicular to the Mercury orbital plane. The current status of the overall MMO system and subsystems such as thermal control, communication, power, etc. are described. The latest status of the development of critical technologies for the MMO and the outline of the international cooperation between ESA and ISAS are also presented.     

The meaning of Japan's space commercialization efforts

The gradual commercial utilization and application of the results of government-led space development programmes is a natural development. In Japan private sector involvement goes further than this because the government budget for space development is very limited. To remain competitive in an increasingly international market Japan now needs to develop a partnership between government and private enterprise to construct a system and structure that will directly benefit the public, otherwise the necessary support for space development will not be attained.     

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.     

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...