Hiroto HABU

As an alternative to hydrazine, ammonium dinitramide-based ionic liquid propellant (ADN-based ILP) was developed. It is mixture of the solid powders: ammonium dinitramide, monomethylamine nitrate, and Urea. It has a feature to be able to adjust the performance of monopropellant by change of the compositions because the constituents have different role: oxidizer, fuel, and freezing point depressant. By adjusting the components, it has high specific impulse and fuel rich and low freezing point comparing to hydrazine. The basic combustion characteristics of ADN-based ILP were investigated in the strand burner tests for application to thruster. The self-sustainable combustion, the linear burning rates, and the flame temperatures were shown in the results. The features of the ADN-based ILP were discussed on the basis of the results. As a problem of the thruster application, the ignition in vacuum was also discussed. (C) 2015 Published by Elsevier Ltd.

Space Transportation Symposium FY2014 (January 15-16, 2015. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan

47th ISAS Lunar and Planetary Symposium (August 4-6, 2014. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan

A new small solid launcher named Epsilon is currently under development in JAXA. The Epsilon launch vehicle is normally three stage rocket system and can be added an optional liquid propulsion system to the third stage for the missions requiring precision orbit insertion. The SRB-A motor boosting the H-IIA vehicle and the H-IIB vehicle will be shared as the first stage motor. Upper-stage motors are inherited from the fifth M-V launch vehicle, from the viewpoints of development cost reduction, performance increase, and advanced technology succession. The solid motor side jet (SMSJ) system, which is used for the roll control during the first stage powered flight and the three-axis control after the SRB-A burnout, will be newly developed based on the technology of the SMSJ for the M-V vehicle. A maiden flight of the first Epsilon is scheduled in the summer of 2013. A successive concept of the advanced propulsion technologies for next-gen Epsilon are also described in the present paper. There are many technical challenges, such as new propellants and mass reduction of nozzle liner, to be tackled with for the next couple of year. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.