Japanese Experiment Module Research Articles

Feasibility Study of Laser Communications on International Space Station.

We are designing the Laser Communications Demonstration Equipment (LCDE) attached to the Japanese Experiment Module “Kibo” on the International Space Station (ISS), for laser communications experiments between the ISS and ground stations. The experiment will demonstrate large-capacity, high-data-rate (2.5 Gbps) two-way communications. A preliminary experiment to detect space debris will also be performed. In the first stage of the experiment, it is necessary to track geodetic satellites and to compensate the optical misalignment of the LCDE in order to achieve precise tracking and pointing. Sunlight reflected from geodetic satellites will be used for tracking. This provides the tracking angle information. As the received power is very low (about - 95 dBm), a sensitive tracking sensor is needed. This paper summarizes the LCDE, studies on the visibility of the geodetic satellites from the ISS, and the tracking performance includingthe sensitivity of the sensor.

NASA Roadmap for Fundamental Physics Research in Space

Last year, about 100 fundamental physics researchers met twice to develop plans for the future in this research area. The results of these meetings have been documented in a presentation package titled “A Roadmap for Fundamental Physics in Space”. A summary of the Roadmap is presented along with an overview of the current program. Research is being performed in Low Temperature and Condensed Matter Physics, Laser Cooling and Atomic Physics, and Gravitational and Relativistic Physics. There are currently over 50 investigators in the program of which 9 are being evaluated as potential flight experiments. The number of investigators is expected to grow further during the next selection cycle, planned to start toward the end of 1999. Experimentation in Space has until now been limited to short duration flights aboard the Space Shuttle. In the near future, our investigators will be able to take advantage of long duration experimentation in Space using a suite of different carriers under development. Experiments needing Low Temperatures will be performed in a liquid helium facility being developed by JPL and Ball Aerospace. This apparatus will allow multiple investigations each flight and will attach to the ISS Japanese Experiment Module's Exposed Facility. Experiments in the Laser Cooling area are developing experiments for the EXPRESS racks inside the ISS US module. Experiments in Gravitational Physics can be performed in the low temperature facility, or can be independent free flyers to fully maximize the benefits inherent in the space environment.

Submillimeter-wave SIS receiver system for JEM/SMILES

Abstract A 640-GHz heterodyne superconductor-insulator-superconductor (SIS) receiver will be installed in Superconducting Submillimeter-wave Limb Emission Sounder (SMILES) on the Japanese Experiment Module of the International Space Station. SMILES will simultaneously detect twelve emission lines of stratospheric molecules in the limb sounding method. The SIS receiver is operating in single sideband (SSB) mode, and we employ a new type of Martin-Puplett interferometer consisting of two sets of a wire grid and a flat mirror for the SSB filter. The SIS mixers and intermediate-frequency low noise amplifiers will be cooled to 4.5 K and 20 K, respectively, by a Stirling refrigerator combined with a Joule-Thomson circuit used for the first time in space.

Research Opportunities on the Low Temperature Microgravity Physics Facility (LTMPF) on the International Space Station

The Low Temperature Microgravity Physics Facility (LTMPF) is a state-of-the-art facility for long duration science investigations whose objectives can only be achieved in microgravity and at low temperature. LTMPF consists of two reusable, cryogenic facilities with self-contained electronics, software and communication capabilities. The Facility will be first launched by Japanese HIIA Rocket in 2004 with at least five months cryogen lifetime on the Japanese Experiment Module Exposed Facility (JEM EF) of the International Space Station (ISS). Future missions will be launched and retrieved by the Space Shuttle. A number of high precision sensors of temperature, pressure and capacitance will be available, which can be further tailored to accommodate a wide variety of low temperature experiments. This paper will describe the LTMPF and its goals and design requirements. Currently there are six candidate experiments in the flight definition phase to fly on LTMPF. Future candidate experiments will be selected through the NASA Research Announcement(NRA) process. Opportunities for utilization and collaboration with international partners will also be discussed.

The X-ray CCD camera of the MAXI experiment on the ISS/JEM

Monitor of All-sky X-ray Image (MAXI), is the X-ray observatory on the Japanese experimental module (JEM) Exposed Facility (EF) on the International Space Station (ISS). MAXI is a slit scanning camera which consists of two kinds of X-ray detectors: one is a one-dimensional position-sensitive proportional counter with a total area of ∼5000 cm 2 , the Gas Slit Camera (GSC), and the other is an X-ray CCD array with a total area of ∼200 cm 2 , the Solid-state Slit Camera (SSC). The GSC subtends a field of view with an angular dimension of 1°×180° while the SSC subtends a field of view with an angular dimension of 1° times a little less than 180°. In the course of one station orbit, MAXI can scan almost the entire sky with a precision of 1° and with an X-ray energy range of 0.5–30 keV. We have developed the engineering model of CCD chips and the analogue electronics for the SSC. The energy resolution of EM CCD for Mn K α has a full-width at half-maximum of ≃182 eV. Readout noise is ≃11 e − rms.

Observation of GRB afterglows with MAXI on JEM/ISS

MAXI is an X-ray all-sky-monitor which will be on the Japanese Experiment Module of the International Space Station. Its objective is to monitor X-ray sources over the entire sky with the sensitivity of less than 3 mCrab in 1 day. The GRB afterglow is one possible objective. One could expect ~25 afterglows to be detected a year at the early stage with this experiment.

MAXI mission for space station and future ASM

MAXI (Monitor of All-sky X-ray Image) is the first astrophysical payload for Japanese Experiment Module (JEM) to be designed for all sky X-ray monitoring. MAXI is a slit scanning camera which consists of two kinds of X-ray detectors; one is one-dimensional position sensitive proportional counters with total area of about 5000 cm2 (here we call GSC) and the other is an X-ray CCD array with total area of about 200 cm2 (here we call SSC). The GSC subtends a field of view with an angular dimension of 1° × 180°, while the SSC has a field of view of 1° × 90°. Thus, in the course of one station orbit, MAXI can scan almost all sky with a precision of 1 degree and with X-ray energy range of 0.5-30 keV. MAXI with a total weight of about 500 kg will be attached to JEM exposed facility (JEM-EF) in 2004. Furthermore, the future ASM with more sensitive detectors having a wide energy band and with better time response/resolution will follow the MAXI mission.

Critical Crack Length Evaluation for JEM Pressurized Module Structure.

The Japanese Experiment Module (JEM), a part of the International Space Station is designed to protect its manned pressurized structure from impacts of Micrometeoroid-Orbital Debris (MM-OD) up to 1 cm in diameter. Though the probability of impacts of MM-OD with a diameter of 1 cm to 10 cm is very low, the occurrence of such large MM-OD impact will damage the JEM pressurized structure. When the damage to pressurized structures is large enough, a catastrophic failure may occur. To assess the probability of unstable structural failure caused by the MM-OD impact, we evaleated the JEM fracture mechanics parameters related to critical crack length. This report summarizes the results of JEM pressurized structure safety evaluation from the fracture mechanics aspects when MM-OD strikes.

Space Debris Protection Shield Performance Evaluation Using Hydrocode Simulation.

The Japanese Experiment Module (JEM) is the Japanese contribution to the International Space Station (ISS). The ISS program has established a strategy for managing the risk associated with the micrometeoroid and orbital debris (MM-OD) threat. A shield configuration was designed for the JEM Pressurized Module. Hypervelocity impact (HVI) tests and hydrocode simulations have been conducted to verify the JEM Pressurized Module shield and structural performance for MM-OD impacts. In this paper, we first report the latest hydrocode simulation results for JEM debris shield design evaluation against the strikes of debris. Next, we report the results of hydrocode simulation for large size (5 and 10 cm in diameter) debris impacts on the JEM shield and pressure structure which were conducted to evaluate the penetration hole size in the module wall.

衛星間光通信用振動アイソレータの性能評価

Inter-satellite communication instruments require a very-high pointing stability and accuracy, for example, on the order of one micro-radian. This is reachable by means of controlling the employed FPM (Fine Pointing Mechanism) in a wide frequency range. The Japanese Experimental Module (JEM) of the International Space Station will have larger vibrational disturbances than general satellites. When these larger vibrational disturbances occur, it will not be adequate to make a high gain controller suppress these disturbances in a wide frequency range for the precise pointing system. Therefore, we prepose the use of a vibration isolator, which is effective for laser communication instruments, to reduce the transmission of vibration from the spacecraft body such as JEM to the pointing system. The vibration isolator we have developed can attenuate disturbances for six degrees of freedom. This paper describes the mechanism, a hybrid control method that consists of passive and active controls, and experimental resul s. The experimental results for properties of the vibration isolator indicate that under severe vibrational circumstances, the vibration isolator can be effective in reducing the transmission of vibration to sensitive instruments. This work was performed under contract with the Communications Research Laboratory.

A conceptual design for cosmo-biology experiments in Earth's Orbit.

A conceptual design was developed for a cosmo-biology experiment. It is intended to expose simulated interstellar ice materials deposited on dust grains to the space environment. The experimental system consists of a cryogenic system to keep solidified gas sample, and an optical device to select and amplify the ultraviolet part of the solar light for irradiation. By this approach, the long lasting chemical evolution of icy species could be examined in a much shorter time of exposure by amplification of light intensity. The removal of light at longer wavelength, which is ineffective to induce photochemical reactions, reduces the heat load to the cryogenic system that holds solidified reactants including CO as a constituent species of interstellar materials. Other major hardware components were also defined in order to achieve the scientific objectives of this experiment. Those are a cold trap maintained at liquid nitrogen temperature to prevent the contamination of the sample during the exposure, a mechanism to exchange multiple samples, and a system to perform bake-out of the sample exposure chamber. This experiment system is proposed as a candidate payload implemented on the exposed facility of Japanese Experiment Module on International Space Station.

航空機による微小重力実験 : JEM青少年プログラム委員会の活動より( 宇宙と物理教育)

航空機による微小重力実験 : JEM青少年プログラム委員会の活動より( 宇宙と物理教育)

Space station JEM design implementation and testing for orbital debris protection

The Japanese Experiment Module (JEM) is the Japanese contribution to the International Space Station (ISS) Program. The core part of JEM is a Pressurized Module where the crew conducts space experiments in a microgravity environment in space. The development of a shield design to protect against micrometeoroids and orbital debris (MM/OD) has been a key issue for the permanent manned space station which is expected to have an operational life exceeding 10 years. Many technical approaches for MM/OD protection have been studied. As the launch of the space station elements draws near, the shield design has become mature, and the technical test data for the MM/OD shielding obtained has increased confidence in its performance. NASDA, which is responsible for JEM design and development, has conducted a series of tests and simulations to define the MM/OD shield configuration and design. The structural failure due to MM/OD strikes has also been assessed for the combined shield and pressure shell configuration.

Space Tribology in Japan

This paper traces research and development in the field of lubrication technology for various mechanical elements. Japan is now in the process of developing the Japanese experimental module (JEM), one component of the US Space Station. This paper therefore emphasizes results relating to mechanical elements that will appear in JEM mechanisms. Methods of lubricating ball-bearings, sliding bearings, ball screws and gears for space use are described and some test results are given.

Robotic manipulators in space: A dynamics and control perspective

Large robotic manipulators are to play a key role in assembly, maintenance, and servicing of future complex in-orbit infrastructures. The first generation space manipulator is the Canadian Remote Manipulator System (RMS), in orbit since 1981. A second generation of large space manipulators is presently under development, for use on the International Space Station: the Space Station RMS, the European Robotic Arm, and the Japanese Experiment Module RMS. Large robotic space manipulators pose significant challenges to the dynamics and control community. This survey paper discusses dynamics modelling issues and control schemes for such systems.

Development of Solar-Pumped Lasers and its Application to Laser Power Beaming in Space.

Power transmission by high power lasers is one of the most attractive methods for energy supply system in space. This paper describes the results of solar-pumped solid state lasers developed by the author's group, and some concepts of laser power beaming proposed in USA and Japan. Finally, we introduce the proposal on the space experiment of laser power beaming at Japanese Experiment Module (JEM) on the space station.

Japan's new long-term vision Creating a space age in the new century

The Japanese Government's Space Activities Commission (SAC) has released its latest Long-Term Vision of Japan's future in the exploration and use of outer space. The Vision will contribute to the formulation of government policy for space development. In this article, the philosophy of space development is defined as follows: ‘It enables space to be used as the common property of all mankind in order to contribute to the enduring prosperity of all those living on Earth.’ Within this philosophy, Japan's principal objectives are projected into the middle of the twenty-first century as being: construction of a global Earth observation system; promotion of advanced space science programmes; full implementation of space activities using the Japanese Experiment Module of the International Space Station; and development and operation of new space infrastructures.

JEM Electrical power system architecture

The paper recalls how JEM EPS (Japanese Experiment Module Electrical Power System) was designed and discusses a generalization of the EPS architecture to the other subsystems of the Space Station Manned Base and their integrity.

European opportunities for astronomical, solar-terrestrial and Earth observation research aboard the space station freedom

The International Space Station Freedom will give opportunities over some 30 years to perform ongoing observational programmes from above the Earth's atmosphere over a band of some ± 28° centred on the equator. The scientific disciplines of astrophysics and solar-terrestrial interactions as well as Earth and environmental observation will be able to benefit from such a long lived observational platform. There are no doubts that a major part of the Space Station research will be filled primarily with microgravity and life science programmes. For European scientists in the disciplines of Space Science and Earth Observation the Space Station Freedom will also offer places to install suitable instruments. Today these are: the External Viewing Platform on the Columbus Attached Lab and specific Resource Ports for small attached payloads on the Space Station truss structure. Additionally external canisters on the Columbus Free Flying Laboratory may be implemented and access may be arranged to the Exposed Facility on the trailing end of the Japanese Experiment Module. Two major studies have laid the groundwork for our synthesized overview. These are the still ongoing Attached PayLoad Support Systems (APLSS) study and the finalized Scientific AirLock (SAL) Study Team reports from 1990/91 and 1989 respectively. In our paper we will give a critical review of some of the considered model instruments and an instrument traffic model for Space Science and Earth Observation particularly with regard to the criteria: compatibility with the ongoing scientific and technological research programmes, and space station restrictions, as well as long-term prospects—as far as this is currently available. Our report provides also an opportunity to update the earlier work against revised opportunities and against more distinct system requirements brought about by the design of all aspects continuing to harden.

The Japanese experiment module for space station freedom

Japan is participating in the International Space Station Program and currently developing a Japanese Experiment Module (JEM) to be attached to the space station. The Space Station Program will contribute significantly to the future Japanese development in the field of life science and microgravity science through the utilization of the space environment. Further, it will provide a valuable opportunity to investigate unknown potentials in space, to acquire new knowledge and thought, and to advance science and technology. This paper describes an overview of the program with emphasis on JEM development status and preparation for its utilization.