Kazuhito Shimada

Mass measuring instrument for use under microgravity conditions

A prototype instrument for measuring astronaut body mass under microgravity conditions has been developed and its performance was evaluated by parabolic flight tests. The instrument, which is the space scale, is applied as follows. Connect the subject astronaut to the space scale with a rubber cord. Use a force transducer to measure the force acting on the subject and an optical interferometer to measure the velocity of the subject. The subjects mass is calculated as the impulse divided by the velocity change, i.e., M=integral Fdt/delta v. Parabolic flight by using a jet aircraft produces a zero-gravity condition lasting approximately 20 s. The performance of the prototype space scale was evaluated during such a flight by measuring the mass of a sample object.

Reconsideration of Body Mass Measurement on the International Space Station and Beyond

In the current space program, astronaut body mass onboard spacecraft, including the International Space Station (ISS) is measured with spring-mass device. We propose a new device “Space Scale” with laser interferometry acceleration measurement and an inline force sensor with a bungee cord. This paper describes concept of Space Scale and its accuracy estimation by ground model test. Accuracy obtained in this ground test was –0.293 %, of which force sensor contributed most to error.

Evaluating 3D position and velocity of subject in parabolic flight experiment by use of the binocular stereo vision measurement

A practical method for evaluating the three-dimensional (3D) position and velocity of a moving object used in the parabolic flight experiment is developed by using the binocular stereo vision measurement theory. The camera calibration mathematic model without considering the lens distortion is introduced. The direct linear transformation (DLT) algorithm is improved to accomplish the camera calibration. The camera calibration result and optimization algorithm are used to calculate the objects world coordinate from image coordinate. The 3D position and the velocity of the moving object are obtained. The standard uncertainty in estimating the velocity is 0.0024 m/s, which corresponds to 1% level of the velocity of the object in the experiment. The results show that this method is very useful for the parabolic flight experiments.

Issues with Body Mass Measurement on the International Space Station (ISS)

Although inception of the measurement of astronaut body mass measurement was as old as Skylab era, progress in the field has not been as expected. There are fundamental physical difficulties as well as program management issues. New mass measurement systems with the current sensor technologies should be prepared, and the new sensor system could be expanded for “Drop Tower” in space.

Mass Measurement in Space, 1964-2010

Mass, with length and time, are the primary triad of dimensions on which all other measurements are based. Mass measurement has been an essential tool of commerce for more than four thousand years and of science and technology for more than two thousand years. It is especially important to biomedical investigation and scientific health care. This is equally true in space, as demonstrated on Skylab. With large bodies such as the Earth, local gravitational attraction of objects on its surface produces the force we call weight, which makes mass measurement simple. Masses can be directly compared to standard or known masses by a balance and indirectly by calibrated counter forces of spring or more recently and more commonly by electronic force measurement. Such gravimetric measurements are so effective that virtually no other means were developed. Except for brief periods, spacecraft are without any force influence except gravity. Any gravitational forces are exactly counter balanced by inertial forces from any acceleration produced by gravity, leaving it and its contents weightless. This situation requires that some other property of mass be used for its measurement and inertial forces are the obvious choice.

Proposal of Intelligent Inventory System for Space Station with IC Tag - Near Real-Time Onboard Inventory Management

Difficulty in inventory management on space station has been known since 1980’s but still is a new problem. We propose the expanded application of IC tags for the International Space Station inventory management. Use of multiple RFID tags can monitor package use status. Where electromagnetic interference or poor radio propagation is a problem, we may apply ultrasound tags.

Space Balance and Space Scale: Mass Measurement Devices (MMDs)

In this paper, mass measurement devices (MMDs) developing by the authors for use in the International Space Station (ISS) are reviewed. First, Space Balance, which is a small mass measurement device (SMMD), is reviewed. In Space Balance, the momentum conservation between two objects, the subject mass and the reference mass, are compared. Then Space Scale, which is a body mass measurement device (BMMD), is reviewed. In Space Scale, a human subject is pulled using rubber string. Force is measured using a force transducer and acceleration is measured using optical interferometer. Both Space Balance and Space Scale have shown high accuracies in the ground experiments.

Improved Method of Direct Measurement of the First-Order Mass Moments of Human Body Segments

The purpose of this research is to reduce the measurement time of the first-order mass moment estimation method proposed by us previously. In the previous method, the loads at the three points of the board are measured one by one using one piece of an expensive scale (model: GX-30KR, resolution: 0.1 g, price: 2,542 USD). The relative standard uncertainly of measurement using a rigid body is estimated to be 1.7% and the measurement time is approximately 10 minutes. In this research, three pieces of inexpensive scales (model: HD-660, resolution: 100 g, price: 17 USD) are used to reduce the measurement time. The relative standard uncertainly of measurement is estimated to be 1.9% and the measurement time is approximately 1 minute. In previous measurement, when changing the position of the scale, the position of the frame has been deviated slightly. However, in this method, this kind of error does not occur, since measurements of three points are simultaneously conducted.

Safety of emerging universal technologies: drone and nano-bubble water

There are new big new universal technologies in research and coming to commercial market. This paper discusses two of them as examples: drone and nano-bubble water, specially their safety aspects. Safety of new technologies are becoming more publicized than before; however, its assessment are more difficult compared with that in the past. Drone: It is also called as UAV (Unmanned Aerial Vehicle, Uninhabited Air Vehicle), UAS (Unmanned Aircraft System), ROAV (Remotely Operated Aerial Vehicle), or aeromodel (up to 5 kg by air sport rules). Their operational rules are heavily discussed world-wide. Governmental controls are mainly focused on security (one found on the roof of Japanese Prime Minister office) and privacy, but also direct contact injuries had happened. JAXA data show that 5 kg test article presented with lethal level of Head Injury Criterion values on human body dummy. The most significant issue is that nobody has a systematic accident database. Nano-bubble water This is a Japanese invented very new technology. When bubbles with diameters less than 100 nanometers are generated within water, they do not dissipate for a long period, typically several months. There certainly are great possibilities and business-opportunities for this, but there are problems. Since no standardized measurement methods are agreed yet, many bottled products were tested to contain no nano size bubbles. There are clinical usage data already, but the core problem is that no precise data exist to show the level of bubble concentration used. We still see confusion in this regard. We are to see big application fields for these. We need to facilitate biomedical safety reviews for new technologies including the two above.

Microbial landscape in space exploration

Recent microbiological study gave us a revised look at how humans interact with microorganisms. That microbial landscape is now extended from ocean bottom to outer space. In addition to panspermia origin of life discussion, we have more immediate issues with space craft biotome and planet probe quarantine. Space exploration planners need to give much more attention to lunar surface quarantine, after 2009 discovery of three Haruyama holes by SELENE probe data, which may suggest water held in undersurface cavern.