Simulation experiments of the cosmic ray isotope telescope on ETS VI

A computer simulation was carried out to evaluate the basic characteristics of a Δ E×E cosmic ray telescope consisting of 23 solid state detectors including 3 position sensitive detectors with large effective area. Based on the simulation, the geometric factor of the telescope is deduced to be as large as 22.5 cm²sr, almost independent of charge and energy concerned. The energy ranges to be covered by the telescope are, for example, 18–98 MeV/n for Li and 56–339 MeV/n for Fe. By analyzing simulated data, the mass resolution for iron in the overall energy range covered by the telescope is estimated as about 0.22 amu in standard deviation. The expected counting rates and mass-histograms are simulated for Galactic cosmic rays and solar energetic particles.     

High-Definition Television System Onboard Lunar Explorer Kaguya (SELENE) and Imaging of the Moon and the Earth

The High-Definition television (HDTV) system onboard the Japanese lunar explorer Kaguya (SELENE) consists of a telephotographic camera and a wide-angle camera that each have 2.2 M-pixel IT-CCDs (interline transfer charge-coupled devices) and LSIs (large-scale integrated circuits) of the several-million-gates class. One minute-long motion pictures acquired by the HDTV system at 30 fps (frames per second) are recorded in a 1 GB semiconductor memory after compression, and then transmitted to a ground station. In the development of the space-going HDTV system, a commercial ground-model HDTV system was extensively modified and evaluated for its suitability to withstand the harsh environment of space through environmental tests. The HDTV acquired a total of 6.3 TB of movies and still images of the Earth and the Moon over the mission period that started on September 29, 2007, and ended on June 11, 2009. Footage of an “Earth-rise” and an “Earth-set” on the lunar horizon were captured for the first time by the HDTV system. During a lunar eclipse, images of the Earth’s “diamond ring” were acquired for the first time. The CCDs and the instruments used in the system remained in good working order throughout the mission period, despite the harsh space environment, which suggests a potential new approach to the development of instruments for use in space.     

Capability for ozone high-precision retrieval on JEM/SMILES observation

We estimate the capability of ozone (O₃) retrieval with the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) instrument attached to the Exposed Facility of the Japanese Experiment Module (JEM) on the International Space Station (ISS). SMILES carries a 4-K mechanical refrigerator to cool superconducting devices in space. Since SMILES has high sensitivity thanks to the superconducting receiver, it is expected that SMILES has ability to retrieve O₃ profiles more precisely than the previous millimeter–submillimeter limb measurements from satellites.     

The spaceborne lidar experiment

Lidar is one of the key sensors to understand global atmospheric environment, so lidar is one of the candidates to be flown on future earth observation satellites. But spaceborne lidar is our first trial and we have some technical issues to resolve before establishing operational sensor. So we start development of the Spaceborne Lidar Experimental Model as a first step of lidar program of NASDA. The Spaceborne Lidar Experimental Model will be launched in early 2001.

The purpose of the Spaceborne Lidar Experiment is technological demonstration of system design and critical components to apply to future operational sensor. And we demonstrate availability of lidar observation data and scientific value.

There are some critical points to resolve such as (1) thermal design of laser oscillator which remove locally-generated-heat effectively and (2) mirror design with little distortion.     

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.     

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.     

Solar power sail membrane prototype for OKEANOS mission

This paper reports on the manufacturing and evaluation of a solar power sail membrane prototype for the OKEANOS project. The in-house prototype was built by the Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency. Mechanical and electrical evaluation tests were conducted. The membrane, thin-film solar cells, reflectivity control devices were good condition after the manufacturing and handling. The improvements in the manufacturing process and design were found. The manufacturing process and design were fundamentally established. After the prototype, improvement plans for the manufacturing process and design were tried. We have a prospect of manufacturing the flight model sail and continue to the development.     

Evaluation of Voigt algorithms for the ISS/JEM/SMILES L2 data processing system

We present a calculation of the accuracy and speed of the Voigt function of various algorithms (Armstrong (1967), Hui et al. (1978), Humlicek (1982) and improved version of Kuntz (1997) developed in this study) for making the faster and higher accuracy forward model required for the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) Level 2 (L2) data processing system.     

An intercomparison of meteor radar measurements at the South Pole using two different processing systems

A new meteor radar system was installed at the Amundsen–Scott station South Pole in 2001 to further the understanding of the dynamics of the Antarctic region. The antenna array consists of four yagis pointed along the 0°, 90°, 180°, and 270° meridians and five folded crossed dipoles arranged in a cross configuration and operating as an interferometer to provide position measurements for the detected radio meteors. The four yagis are time division multiplexed and used for both transmitting and receiving while the five folded crossed dipoles are only used for reception. The current arrangement of data acquisition (DAQ) systems at the South Pole allows the collection of meteors in a configuration similar to the previous meteor radar system that operated at the South Pole in the mid 1990s while also using an interferometer to accurately determine the meteor positions in the sky, which enables the determination of the vertical structure of the observed waves. This has been accomplished through the use of two DAQ and post-processing systems: COBRA (Colorado Obninsk radar) connected to the yagis and MEDAC (meteor echo detection and collection) connected to the folded crossed dipoles. With two separate DAQ systems operating in parallel we have the ability to directly compare the results and understand the inherent variability in the derived scientific results based on different system architectures and processing assumptions. The impact of operating a system without an interferometer on the amplitudes and phases of the observed wave components is considered. We find that the lack of altitude resolution of the COBRA DAQ system leads to an underestimation of the amplitude of the s = 1 component of the semidiurnal tide of ∼20% during the summer months.     

Experimental results of the Japanese BSE program

The Japanese Medium-scale Broadcasting Satellite for Experimental Purpose (BSE) is a three axis stabilized spacecraft having a Sun-oriented solar array for high power generation. This paper will present the BSE mission objectives, spacecraft and ground systems configurations and some of experimental results on TV broadcasting, K-band radio-wave propagation, etc.