We have developed a device for walking rehabilitation which has a treadmill in a lower body positive pressure (LBPP) chamber to unload the lower extremities. In this review, we summarize the present knowledge of effects of gravity, LBPP, and walking on leg fluid turnover in standing human. Prolonged standing caused swelling in the legs due to an effect of hydrostatic pressure. Circumferences of leg gradually increased during standing still and reached a plateau level after 30-40 minutes. Exposure to LBPP significantly improved the swelling in the thigh, suggesting that the LBPP possibly reduces fluid filtration by decreasing transmural pressure gradient in the capillaries and/or increases lymphatic outflow from the tissue. Walking also decreased the leg swelling by muscle pump activity, and this effect was further enhanced by applying LBPP. These results suggest that applying LBPP can change the body fluid turnover, resulting in a decrease in the tissue fluid of the legs in standing and walking human.

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In a microgravity environment, the volume load on the left ventricle is reduced and the cardiac function deteriorates.Consequently, maximal oxygen consumption (VO₂max) decreases during spaceflight. Reduced cardiac function can lead to serious health problems such as cardiac atrophy, diastolic dysfunction, and orthostatic hypotension. An exercise using a bicycle ergometer during spaceflight may help to increase the volume load on the left ventricle. On the other hand, many astronauts also experience weight loss during spaceflight because energy imbalances can occur. Some researchers indicate that excessive exercise may promote the energy deficit and have a negative impact on long-term spaceflight. Therefore, we have been devising an original bicyle erogometer protocol better suited to astronauts experiencing long-term spaceflight.One of our candidate protocols is the 3 × 3 protocol named J-HIAT, i.e., three times 3-min intervals with a 2-min active recovery period between intervals. In response to our preliminary experiments, we concluded that J-HIAT would be a potential protocol to control the increase of energy consumption and to have a significant impact on VO₂max and the cardiac function. To further verify this method, we are working on full-scale experiments. In future, we will show the results of these experiments.

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The analysis of biospecimens from astronauts reveals considerable important information about their healthcare, but transportation of such samples will become difficult after the retirement of the Space Shuttles. We focused on hair, which is one of the easiest specimens to obtain, store and return, and planned this "Biomedical Analysis of Human Hair Exposed to Long-term Space Flight (Hair)" study. The main objective of the present part is to verify whether changes in mineral metabolism can be detected through analysis of hair shafts from astronauts on the International Space Station.Ground-based studies were performed to establish an optimum methodology for analyzing trace elements (e.g., calcium, sulfur and chlorine) on the cross-sectional surface of a hair shaft. By using Electron Prove Micro Analyzer (EPMA), we could identify the distribution of minerals in human scalp hairs. In another animal study, a centrally distributed concentration of calcium was observed in hairs from the mice exposed to microgravity. In this paper, we will report on the overall research plan and the progress we have made to date.

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In the science field, disseminating new information to the public is becoming increasingly important, since it can aid a deeper understanding of scientific significance and increase the number of future scientists. As part of our activities, we at the Japan Aerospace Exploration Agency (JAXA) Space Biomedical Research Office, started work to focus on education outreach featuring space biomedical research. In 2010, we launched the Mission X education program in Japan, named after “Mission X: Train Like an Astronaut” (hereinafter called “Mission X”), mainly led by NASA and European Space Agency (ESA). Mission X is an international public outreach program designed to encourage proper nutrition and exercise and teaching young people to live and eat like astronauts. We adopted Mission X's standpoint, and modified the program based on the originals to suit Japanese culture and the students' grade. Using astronauts as examples, this mission can motivate and educate students to instill and adopt good nutrition and physical fitness as life-long practices.Here we introduce our pilot mission of the “Mission X in Japan” education program, which was held in early 2011. We are continuing the education/public outreach to promote the public understanding of science and contribute to science education through lectures on astronautical specialties and knowledge.

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Using the laser energy transmission technology, we have succeeded to fly a small airplane and a helicopter for a long time (infinite time in principle). Extrapolating the technology, it can be concluded that the technology is available for the near earth space mission in which we cannot use the solar energy such as the ice exploring rover in the bottom of the crater on the lunar polar region. For the application to a deep space mission is challenging, and looking the progress of LISA project (NASA-ESA), it is not impossible.

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TEchnical Data Acquisition equipments (TEDA) on the first Quasi-Zenith Satellite (QZS-1) "MICHIBIKI" was launched by the H-IIA Launch Vehicle No.18 on September 11, 2010 from the Tanegashima Space Center. The TEDA consists of sensors of three types; Light Particle Telescope [LPT, including Alpha particle and Proton Sensor-B (APS-B) and Electron Sensor-A (ELS-A)], Magnetometer (MAM), and Potential Monitor (POM). The TEDA on the QZS-1 has collected these data of space environment from September 21, 2010, these data will help us to identify the cause of the satellite anomaly. This paper describes some results from these data analysis on the QZS-1 orbit.

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Disturbances of Space environment around the Earth (geospace) is controlled by the activity of the Sun and the solar wind. Disturbances in geospace sometimes cause serious problems to satellites, astronauts, and telecommunications. To minimize the effect of the problems, space weather forecasting is necessary. In Japan, NICT (National Institute of Information and Communications Technology) is in charge of space weather forecasting services as a regional warning center of International Space Environment Service. With help of geospace environment data exchanging among the international cooperation, NICT operates daily space weather forecast service every day to provide information on nowcasts and forecasts of solar flare, geomagnetic disturbances, solar proton event, and radio-wave propagation conditions in the ionosphere. For prompt reporting of space weather information, we also conduct our original observation networks from the Sun to the upper atmosphere: Hiraiso solar observatory, domestic ionosonde networks, magnetometer & HF radar observations in far-east Siberia and Alaska, and south-east Asia low-latitude ionospheric network (SEALION). ACE (Advanced Composition Explorer) and STEREO (Solar TErrestrial RElations Observatory) real-time beacon data are received using our antenna facilities to monitor the solar and solar wind conditions in near real-time. Our current activities and future perspective of space weather monitoring and forecasting will be introduced in this report.

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The primary objective of ERG project is a better understanding the acceleration mechanism of the energetic particles in the radiation belt. An important part of the science mission is to investigate the role of Pc 5 pulsations in frequency band between 1.67 and 6.67 mHz for transporting the energetic electrons. ERG will provide the simultaneous measurements of three-dimensional plasma distributions covering a wide range from eV to MeV, electric and magnetic fields, and plasma waves, near the equatorial plane where the electron accelerations can occur. These measurements might demonstrate the relationship between Pc 5 pulsations and the transportation of electrons. This paper shows the examination of Pc 5 pulsations measured by the THEMIS spacecrafts as the preliminary preparation of the ERG observation. By combining both the five THEMIS spacecrafts and the ground-based magnetometer, we can find the spatial distribution of Pc 5 pulsation in the inner magnetosphere. Particularly, the polarization of Pc 5 pulsation is identified by the in-situ magnetic and electric field measurements. With a focus on the Pc 5 pulsation, we also present the scientific effort by ERG to the understanding of the inner magnetosphere dynamics.

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Small debris, from 100 μm to 1 mm, can cause severe damages when impacting on a spacecraft surface. However for this size range there is a lack of data. Therefore it is important to develop systems able to estimate accurately the number of impacts at which a spacecraft is exposed during its lifetime. An active in-situ debris sensor has been developed for this purpose and will be mounted on a small satellite, which will operate in polar orbit for a mission of one year. The sensor's area is 81 cm² for a weight of 23 g. Two types of information can be deduced: the number of impacts and the approximation of debris size. On this paper is reported the installation of the sensor on the small satellite as well as its working principle. Besides, minimum detectable size of debris and collision probability have been estimated. The latter has been calculated to be only 2.8% due to the smallness of the detector and to the shortness of the mission. Nevertheless its capability to detect broken lines and to transmit the data to OBC has been demonstrated. Thereby this active in-situ space dust measurement system is very promising for its lightness, low-cost, and ability to provide immediate data on the space debris population.

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Results of the collision avoidance operation at the German Space Operations Center (GSOC) are presented in this paper. Currently, five operational satellites in the LEO region are supported in the monitoring system. In addition to the daily prediction using Two-Line Elements (TLEs) as source of orbital elements for space objects, possible critical approaches are also detected by the proximity search performed by Joint Space Operations Center (JSpOC). An automated alarming system is available for both screening results, and the detailed risk evaluation is performed by the Flight Dynamics team in case of a remaining high risk. After the introduction of the operational collision avoidance procedure, the risk assessment process for critical close approaches as well as the maneuver planning strategy are further discussed in this paper. For the two operational satellites TerraSAR-X and TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement), which are controlled against a reference orbit inside a control tube with a diameter of 500 m and in a very close formation (min. distance of about 400 m), a dedicated mitigation strategy has to be applied to minimize the violation of strict mission requirements. Two cases of the recent critical approach are presented for these satellites, which lead to the execution of a collision avoidance maneuver after a careful risk assessment, followed by the operational experiences and feedbacks.

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Porous materials absorb impact induced shock well. The pore crushing process results in the compaction of the target, and a considerable part of the impact energy is thought to be consumed in this process. In the case of the impact on gypsum targets, 31 to 62% of the impact energy was distributed into compaction. In this study, applicability of this effect of compaction to develop lightweight debris bumper shields is considered through impact experiments. Porous aluminum plates were employed as targets and solid aluminum spheres, 1.0 mm and 0.3 mm in diameter, were used as projectiles.Normal impacts at about 6 km/sec produced bulb shaped craters. Damaged depths in targets were at most 71% of the ones estimated from impact craterings on solid aluminum plates sharing the same mass per unit area with these porous aluminum plates. Little high speed ejecta was observed by a high-speed video camera.

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In order to limit orbital debris, unmanned spacecraft design needs to comply with ISO 24113 ‘Space systems - Space debris mitigation requirements’ or any standards equivalent to it. In addition to that, to limit orbital debris generated by collisions, unmanned spacecrafts should be protected against small debris impact which may cause failures of critical components for post mission disposal. This paper proposes a spacecraft design procedure based on the quantitative estimation of the small debris impact.

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Electron radiation belts change dramatically over a period ranging from a few seconds to as long as years. It is well known that the energetic electron flux varies during geomagnetic disturbances and that relativistic electrons in the other radiation belt change with solar wind speed. However, electronic direct observation (10 eV-20 MeV) in the field of acceleration has not been realized to date. To investigate the radiation belt, a smallsat Energization and Radiation in Geospace (ERG) is planned. One purpose of the ERG mission is to reveal the acceleration mechanism of high energy particles in the radiation belt. To achieve this, the ERG will observe electrons directly, which are thought to be accelerated to high energy. In the present paper, we introduce the performance of Extremely High-Energy Plasma/Particle sensor for Electrons (XEP-e) and response result of the sensor by GEANT4 simulations.

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The current status of free-flight testing with the gas driven two-stage light gas gun in JAXA Kakuda was reported. Modifications of the gun were followings. (1) Maximum pressure of the pump tube end section was increased from 100MPa to 200MPa, (2) Test section for 15mm gun barrel was extended from 5m to 6.5m with an additional optical windows located at the test section, (3) 4-pieces sabot for 15mm diameter gun barrel (4) High-speed video camera and high-wattage light source. (5) Newly built 72mm diameter gun barrel for 50mm diameter projectiles and (6) 2-pieces sabot for 72mm diameter gun barrel. The 15mm diameter gun barrel was going to be used for the study for aerodynamics under hypersonic condition. The 72mm diameter gun barrel was going to be used for the study on the aerodynamic instability of re-entry capsules under transonic to supersonic condition. In a test campaign with the 15mm diameter gun barrel, we have launched 5mm diameter sphere projectiles with 4-piecies sabot at a velocity at the gun barrel muzzle of 2.1km/s to 3.8km/s. We successfully observed sabot separation and projectile (5mm diameter steel sphere) release through the high-speed video camera. In a test campaign with the 72mm diameter gun barrel, we successfully conducted to launch Apollo shaped capsule projectile of 50mm diameter with 2-pieces sabot at a velocity at the gun barrel muzzle was approximately 430m/s. Our in-housed quasi-one-dimensional Navier-Stokes code was applied to determine safety operation condition of the 72mm gun barrel and to estimate projectile speed.

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There is a lot of debris in space. There are currently about 15,000 individual pieces of space debris that can be observed from the earth, with a likely even greater number existing with a size less than 10cm, the limiting size of earth-based observations. Fears exist that as space debris continues to increase, the Kessler Syndrome will occur, eventually preventing any form of spaceflight. The purpose of this research is to remove the debris to prevent such a situation from happening. For the first time, it is proposed to bias voltage on net electrodes, as the space debris will be charged by the plasma interaction. The charged debris will then be slowed by the electric field surrounding the net electrodes, causing the debris to re-enter the atmosphere. In this research, a 100μm copper powder is used, followed by 2mm Ellenpall. This presentation addresses how much the debris is charged and how far the debris is shifted by the electric field.

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Many microsatellites developed and operated by university teams have been launched in recent years. However, some of the microsatellites faced fatal problems in operation and could not fully achieve their missions due to the teams’ lack of experience. Since it is difficult for teams to forecast and avoid fatal problems, they have not accomplished the real space missions yet. Although the accumulation of experiences is necessary to avoid fatal problems, a single team is not able to develop enough satellites to encounter each possible problem, and newcomers lack the experience to predict and prevent all problems. Experiences and knowledge gained by the experienced teams should be shared among all university teams, including newcomers. In this study, we analyzed the success and failure of CubeSats and university microsatellites statistically to understand the present situation and forecast the future of microsatellite development. In addition, to gather detailed data, we conducted a questionnaire investigation about the failures and the development environment at Japanese universities with teams that have developed microsatellites. We reveal their various trends and problems and predict the number of launched CubeSats and mission success probability. Additionally, we highlight the potential to predict half of the failures using tests.

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High reliability is an essential requirement for avoiding failures in the development of mid-to-large size satellites, which has a major impact on development costs. Conversely, since 2000, several universities have developed and launched low-cost nano-satellites for the purpose of education. Low cost and fast development are key factors in expanding the market for satellites, and balancing cost and reliability becomes a key objective. This paper presents the concept of reasonably reliable systems engineering, which can be considered in terms of the process and the product. In the process approach, we propose a meta-process with an integral quality assurance concept. In the product approach, we introduce a new categorization of failures and propose effective counter measures for each category. Using the product approach, we calculate the probability of service. We applied this method to nano-satellite design and illustrate it with an example of satellite architecture design.

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The Moon Station (“Tsuki Tansa Joho Station” in Japanese, http://moonstation.jp) is one of the most popular outreach and information site for domestic and world lunar and planetary exploration since November 1998. Beginning from the introduction and publication of Japanese lunar exploration called SELENE (now called as Kaguya), the site grew as the foremost portal of general lunar exploration, now independent from JAXA and any other space-related organizations. The site covers wide variety of content from professional writings to public attraction such as rebuttals to "Apollo lunar landing hoax". The Moon Station now attracts more than 60,000 access (6,000 pageviews) per day in average. The site features vast amount of current, past and future explorations and their scientific background. The site is managed under collaborations with planetary scientists and space engineers both in Japan and worldwide to assure accurate content and quick information provision. This variety and maintaining of contents are the main reason of continuance and attraction of the site for more than ten years.

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Space education has been the leading role to inspire the young to hold interest in science and technology and learn to set goals. Japanese university students who want to actively participate in these kinds of activities are increasing. However, when students tempt to carry out space education on their own, they confront difficulty to get financial support, place and time. In this paper, we show the example of the lecture carried out during IAC 2010, which could be one of the solutions for the problems for Japanese university students.

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The activities of the Yokohama Chapter of Young Astronauts Club-Japan are introduced as an example of space education. The main theme of the workshop is atmosphere of the earth. In the workshop, they learned of the history of the earth, compared the earth with other planets, studied the material cycle, and gained a good feel for the course of the earth up to the present. The workshop shows that thinking "on a universe scale," the most essential characteristic of space education activities, produces great educational effects.

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The outer space utilizations play a vital role for both civil and defense fields. As for Japan, after the Basic Space Law was enacted, the new utilizations and R&D of space are promoted to enforce the national security. Under the circumstances, Dual-Use has become an important concept. However, the past studies were often focused on the technologies themselves which could be used for both civil and defense purposes as well. This paper deals with Japanese space policy, focuses on the Dual-Use concept on civil and defense uses and developments of outer space. First, the meaning of Dual-Use concept and the effectiveness of the system would be defined, and the key aspects such as data policy for integrating the dual system were dissected. Then, the operational configurations and retaining Dual-Use system were suggested, and early warning satellite system and space situational awareness project as the concrete applications of Dual-Use system would be discussed.

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In Japan, its main launcher, H-IIA, was privatized in 2005 and is now operated by the Mitsubishi Heavy Industry, and this was an important turning point for all of the space industries, government and space agency(JAXA) in Japan. However in Europe, the Ariane rocket series have been operated by private company, Arianespace, for more than a few decades and now Arianespace has the largest share in the space transportation market in the world. Based on this situation, this paper is to compare and analyze the form and legal framework of the privatization of space transportation, especially focusing on the difference between Europe and Japan.

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