Japan Aerospace Exploration Agency (JAXA) has been established in Oct. 1, 2003, after the merger of three Japanese space organizations, i.e. National Space Development Agency of Japan (NASDA) , National Aerospace Laboratory of Japan (NAL) and Institute of Space and Aeronautical Science (ISAS). Discussion and coordination on how to build the new space organization in both governmental side and former three organizations' side were initiated by the decision of the Minister of Education, Culture, Sports, Science and Technology (MEXT) in Aug. 2001. Here are summarized the chronicle of the consolidation processes and the structures of newJapanese space organization, JAXA. The structures within JAXA for the promotion of science in space environmental utilization are also outlined.
In Japan Aerospace Exploration Agency, JAXA, which was established at October 1, 2003, the research group of Department of Space Biology and Microgravity Sciences, and Office for ISS Science Project, which were established at October 1, 2003, are delegated to promote the microgravity science program onboard ISS as well as the related groundbase research inJapan Aerospace Exploration Agency, JAXA. The activities of the group are mainly focused on material science, life science, and other basic sciences, such as fundamental physics and chemistry, under the steering of Committee for Scientific Utilization of Space Environment, the member of which represents each science research community.
JAXA has been conducting the promotion activities to demonstrate the effectiveness of space experiments as industrial application, and to establish new suitable JEM utilization promotion systems for future industrial or commercial users. This paper describes the status activities and issues on applied research utilization promotion and perspective on new utilization promotion activities under the condition of space organization reconstruction, for next generation potential users.
As utilization of the Japanese Experiment Module (JEM) are getting reality by starting the human stay in the International Space Station, needs of new type utilization of the ISS/JEM that makes use of the feature of manned space activity like an education, creative company activities, new culture, and the arts, etc. have been actualized. In this report, I'd like to introduce the various activities which have been done to pioneering up to now in the education, private organizations, culture, humanities and social science fields, and also introduce an approach for such utilization fields for the ISS/JEM by JAXA.
Scientific domains under microgravity have been expanded according to the progress of space station programs. Since future missions in space experiments are extending to biotechnology, medicine and nanotechnology in relation to the great challenge of human exploration to Mars, we recognized to re-organize the scientific disciplines of micorgravity research programs. We remapped the fundamental sciences using ISS as: 1) fluid sciences which investigates transport phenomena and physics of materials processing, 2) fundamental physics which investigates physical laws in the microscopic scales regulating the complex nature of our world, and 3) chemistry which realizes nanoscale to mesoscale structures from molecular levels and investigates elementary chemical processes in space environment.
Here we review several interesting and important physics aspect of solid 4He in microgravity. Solid 4He is produced at low temperature by applying an external pressure of about 25 bar on superfluid. Due to almost no latent heat involved in the phase transition and the rapid mass transfer in superfluid, the growth coefficient of solid 4He is enormous. This fact enables us to study the true equilibrium crystal shape, which cannot be done with any other material. Thus, solid 4He at low temperature is the ideal system to study the fundamental physics of a crystal: equilibrium crystal shape, roughening transition, quantum surface physics, etc. Unfortunately solid 4He is strongly affected by the Earth's gravity, so that the ultimate study must be done in microgravity. A possible way these experiments can be performed on the ground is proposed.
Thermal energy applied to a pure material near its critical point immediately makes a strong expansion. This causes an adiabatic compression in the front of the expansion and a large density difference is formed there. The difference with adiabatic energy is transported as an acoustic wave. This rapid heat transportation is called ‘‘Piston Effect. ’’ In our study, an ultra-sensitive and high-speed density measurement system was developed to observe the elementary process of‘‘ Piston Effect. ’’ To demonstrate the performance of the system, the measurement of sound velocity in a critical fluid was conducted. Numerical simulations were also made to confirm the experimental results. Using the FFT method to both of the experiment and the simulation, the sound velocity could be precisely evaluated. The velocity profile versus temperature from the experimental results shows a good agreement with the simulation results and theoretical prediction, that is, the velocity rapidly decreases as the fluid approaches its critical point. This indicates that our experiments and simulations complementally enable us to quantitatively discuss the critical phenomena.
Interferometry is an effective method for the in-situ measurement of the faint-growth/dissolution rate of a crystal in a solution, in which the distortion of the observation cell due to the thermal expansion of the materials is sometime larger than the growth/dissolution of the crystal. Thus, it is necessary to establish the way to obtain the real growth/dissolution length by subtracting the displacement due to the distortion from the actual interferometric data. To estimate the behavior of the cell during heating, we observed the interference fringes from two glass windows simultaneously by employing a Michelson interferometry. The distortion of the cell was successfully separated into the expansion of volume of a solution and that of the cell holder. This analysis would also contribute to design the growth cell for the measurement of a very small growth rate of crystals in space.
In the near future, cryogenic propellants will be managed on orbit for space transportation systems. Resupply of cryogenic fluids on orbit is one technology area common to all future space missions. To arrive at this technology, gas-liquid separation and heat management will have to be developed. We propose a new fluid transfer technique, which employs centrifugal force in swirl flow for the gas-liquid separation. In addition, the condensation of vapor in the gas phase is promoted by supplying a spray of cold liquid. First, we conducted a preliminary experiment of tank pre-chill and gas-liquid separation by centrifugal force without a phase change in microgravity using an aircraft. Further analyses of swirl flow behaviors were conducted by means of the computational program FLOW-3D. Second, to construct a thermal analytical model required for the design of cryogenic fluid resupply technology, a one-dimensional thermal analytical model was created by means of the computational program SINDA/FLUINT and the evaluation of this model was conducted by a refilling experiment using liquid nitrogen.