Tomonao Hayashi

Japanese first double lunar swingby mission “Hiten”

Abstract The paper discusses the Japanese first lunar mission named “Hiten”. The spacecraft system, its major mission objectives, namely, the double lunar swingby experiments and the insertion of a miniaturized sub-satellite into an orbit around the moon, are presented. The results of these engineering missions, and other experiments such as optical navigation, packet telemetry by use of a fault tolerant computer and detection of micro-meteorite particles in space of the Earth-moon system, are also described. A couple of follow-on missions, which may be conducted if the Hiten spacecraft will survive the aerobraking experiments at the end of its original 1 year mission life, are discussed. These follow-on missions include an excursion to the Lagrange points of the Earth-moon system and orbiting the Hiten spacecraft itself around the moon.

Flexible Channel Multiplier

A flexible channel secondary electron multiplier tube for use in detector of a mass spectrometer, a detector for the photons and charged particles in the cosmic space and an image intensifier, which is made up of electron-conductive polymers having a secondary electron emitting effect and which, therefore, can easily be produced by extrusion molding and which do not require the inner surface thereof to be coated with a secondary electron emitting substance. The secondary electron emission coefficient delta of the tube is 2.0 with respect to primary electron of 250 eV, and the gain thereof is higher than that of conventional glass tube channel secondary electron multipliers. The tube can be used by bending it at an optional curvature so as to eliminate the undesirable influence of ion feedback, and can be produced at a lower cost than a conventional one.

Quadrupole Field in Circular Concave Electrodes

The fields in circular concave electrodes with both infinitesimal and infinite thickness are analyzed by giving appropriate boundary conditions, and the optimum electrode angles for approximating the ideal quadrupole field best are obtained. These angles are 44° for infinitesimal thickness and 37° for infinite thickness. These results are verified by field plotting method. The realization of these electrodes is also discussed.

Usuda deep space station with 64-meter-diameter antenna

Abstract Institute of Space and Astronautical Science (ISAS), Japan, constructed a new deep space ground station with 64-meter-diameter antenna at Usuda-cho, Nagano, in 1984. The station has successfully operated in the tracking of “Sakigake”, the first Japanese interplanetary spacecraft that ISAS launched on January 8, 1985. This paper describes the facilities and the features of the Usuda Station, the results of Sakigake tracking, as well as the features of the softwares for trajectory generation and orbit determination that we have developed for deep space missions.

Quadrupole electrodes with flat faces

A method to analyze multipole fields formed with flat‐face electrodes by using conformal mapping is described. Quadrupole fields of various parameter values which define the electrode shape are analyzed by this method, and the optimum parameter values for making distortion components of the field minimum are obtained. This result is also useful in designing the shapes of magnetic quadrupoles.

MUSES-A double lunar swingby mission☆

Abstract MUSES-A is Japans first double lunar swingby mission conducted by the ISAS (Institute of Space and Astronautical Science). The main objective of the MUSES-A mission is the verification of the technology and techniques, which are inevitably required for planetary or lunar missions, such as swingby or orbiting around a certain heavenly body, navigation, attitude and orbit control, telecommunication at X-band frequency, related ground control and operation hardware and software, etc. The MUSES-A spacecraft has a cylindrical shape and the mass is 194 kg including 12 kg of a tiny lunar orbiter which is installed on top of the spacecraft. The MUSES-A program started in 1985, and the launch is planned for early 1990.

Japanese deep-space station with 64-m-diameter antenna fed through beam waveguides and its mission applications

The Usuda Deep Space Center of the Institute of Space and Astronautical Science is a Japanese spacecraft tracking station constructed in October 1984. The station is equipped with a 64-m diameter antenna and associated electronics to support deep-space missions. The paper describes the 3-year development process of the station. The beam-waveguide configuration is described in detail to demonstrate its flexibility to modifications in order to adapt to subsequent missions. System configuration and operation examples are also given for several missions. >

Effect of Longitudinal Magnetic Field on the Performance of a Channel Electron Multiplier

The effects of a longitudinal magnetic field on the performance of a channel electron multiplier are studied and the gain variation due to the magnetic field is explained by considering hopping and gyrating motion of electrons.

Quadrupole Field in Circular Concave Electrodes with Finite Thickness

The influence of the finite thickness of circular concave quadrupole electrodes on the spatial higher harmonics is investigated. A design curve for obtaining the proper electrode angle to best approximate the quadrupole field is given by analyzing the results of field plotting. The residual higher harmonics which are mainly due to the 20‐pole field component are confirmed to be negligibly small in the vicinity of the axis. The effect of the finite size of the conducting paper used in the field plotting on the measured amplitude of the spatial higher harmonics is also estimated.

Recent development of scientific satellites and their launch vehicles

Abstract The Institute of Space and Aeronautical Science (ISAS), University of Tokyo, has been engaged in the development of scientific satellites and their launch vehicles of Mu series. ISAS has conducted the first flight test of M-3S, the newest version of Mu series, and launched a technology test satellite MS-T4 into an orbit. The objectives were to verify the overall performance of the vehicle and to perform various experiments on the satellite technology to be applied to the following scientific satellites. Technological aspects of M-3S and MS-T4 are reviewed in reference to the recent trend in the scientific satllite program.