Yasuhiro Morita

© 2018 Univelt Inc. All rights reserved. The Epsilon launch vehicle, the newest version of Japan’s solid propulsion rocket, made its maiden flight in September of 2013. The purpose of the Epsilon launch vehicle is to provide small satellites with responsive launching with low-cost, user-friendly and efficient launch system. The first flight was successfully finished, JAXA has been conducting intensive researches on a more powerful and lower cost version of Epsilon. In order to minimize technical risks and to keep up with demand of future payloads, JAXA plans to take a step-by-step approach toward Future Launch System. As the first upgrade toward Future Launch System, JAXA has started the development of the Enhanced Epsilon. This development is mainly the renewal of the second stage, and also includes each subsystem’s improvement. This paper describes the development and flight result of the Enhanced Epsilon’s Guidance and Control System.

The development of the Epsilon launch vehicle, Japan's next generation solid rocket launcher, has just moved to the final stretch for its first launch scheduled in the summer of 2013 to carry the planetary telescope satellite SPRINT-A. The JAXA appreciates the advantages of combined benefits of the standardized small satellites and the Epsilon's highly efficient launch system in order to increase the level of space activities. The primary purpose of Epsilon is to provide small satellites with a responsive launch that means "Small, Low cost, Fast and Reliable". The attention should be directed toward the innovative design concept of Epsilon, which aims at developing the next generation technologies such as the highly intelligent autonomous checkout system and the mobile launch control. Now that the full-scale development is about to be finished, the most important is what the next step should be beyond the Epsilon. This paper deals with the significance of the Epsilon launch vehicle and how it contributes to the possible evolution of future space transportation systems.

平成25年度宇宙輸送シンポジウム（2014年1月16日-17日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000016009レポート番号: STCP-2013-009

The M-V launch vehicle of Japan Aerospace Exploration Agency (JAXA) has successfully injected Japan's fifth X-ray space telescope "SUZAKU" into its low earth orbit in this past July. The attitude and vibration control algorithm of the M-V rocket used to be highlighted by its H-infinity robust stability since its first flight conducted in 1997. Beyond this, its robustness character has been further enhanced using the mu-synthesis approach to get better robust characteristics not only in stability but in tracking performance under uncertainty of the system dynamics. The performance has been validated by the latest back-to-back successful flights of the vehicle: in May 2003 to directly inject Japan's first asteroid sample return spaceship "HAYABUSA" into the planned inter-planetary trajectory and in this past July to launch the telescope. The mu-synthesis has been applied for the first time ever for Japan's launcher control beyond the reliable H-infinity design. The plant dynamics has an extremely high-order and unstable characteristics, thus the standard mu-synthesis format cannot be directly applied. The paper gives a unique methodology to apply the theory to such a real high-order complicated system. (c) 2007 Elsevier Ltd. All rights reserved.

The M-V launch vehicle of Japan Aerospace Exploration Agency (JAXA) has successfully injected Japan's fifth X-ray space telescope "SUZAKU" into its low earth orbit in this past July. The attitude and vibration control algorithm of the M-V rocket used to be highlighted by its H-infinity robust stability since its first flight conducted in 1997. Beyond this, its robustness character has been further enhanced using the mu-synthesis approach to get better robust characteristics not only in stability but in tracking performance under uncertainty of the system dynamics. The performance has been validated by the latest back-to-back successful flights of the vehicle: in May 2003 to directly inject Japan's first asteroid sample return spaceship "HAYABUSA" into the planned inter-planetary trajectory and in this past July to launch the telescope. The mu-synthesis has been applied for the first time ever for Japan's launcher control beyond the reliable H-infinity design. The plant dynamics has an extremely high-order and unstable characteristics, thus the standard mu-synthesis format cannot be directly applied. The paper gives a unique methodology to apply the theory to such a real high-order complicated system. (c) 2007 Elsevier Ltd. All rights reserved.

This paper presents a methodology for applying mu-synthesis to a real high-order system: launch vehicle attitude and vibration control. The design involves robust characteristics against uncertainties of the system parameters as well as precise tracking performance under limited rigidity. As the plant dynamics has an extremely high order and unstable character, the standard mu-synthesis cannot be directly applied. Thus, the standard procedure is modified in a special way in order to make the approach more efficient. The methodology provided in the study will contribute to a better understanding of how to apply the robust control theory to complicated real problems.

This paper presents a methodology for applying μ-synthesis to a real high-order system: launch vehicle attitude and vibration control. The design involves robust characteristics against uncertainties of the system parameters as well as precise tracking performance under limited rigidity. As the plant dynamics has an extremely high order and unstable character, the standard μ-synthesis cannot be directly applied. Thus, the standard procedure is modified in a special way in order to make the approach more efficient. The methodology provided in the study will contribute to a better understanding of how to apply the robust control theory to complicated real problems.

June, 2004

Altitude control of winged a body is realized with predictive functional controller (PFC). Although the predictive controllers are more or less in the domain of process industry, this paper proves that computational efficient PFC can be implemented on the systems with fast dynamics. The nonlinear model of winged body was written in the form of Takagi-Sugeno fuzzy model, the form that is suitable for implementation with PFC. High quality control requirements are short settle time with aperiodical step response and zero steady state error and was achieved using PFC. Predictive controller proved as a good solution.

June, 2004

Altitude control of winged a body is realized with predictive functional controller (PFC). Although the predictive controllers are more or less in the domain of process industry, this paper proves that computational efficient PFC can be implemented on the systems with fast dynamics. The nonlinear model of winged body was written in the form of Takagi-Sugeno fuzzy model, the form that is suitable for implementation with PFC. High quality control requirements are short settle time with aperiodical step response and zero steady state error and was achieved using PFC. Predictive controller proved as a good solution.

Despite huge amount of data collected by the previous interplanetary spacecraft and probes, the origin and evolution of the solar system still remains unveiled due to limited information they brought back. Thus, the Institute of Space and Astronautical Science (ISAS) of Japan has been given a commitment to pave the way to an asteroid sample return mission: the MUSES-C project. A key to success is considered the reentry with hyperbolic velocity, which has not ever been demonstrated as yet. With this as background, a demonstrator of atmospheric reentry system, DASH, has been designed to demonstrate the high-speed reentry technology as a GTO piggyback mission. The capsule, identical to that of the sample return mission, can experience the targeted level of thermal environment even from the GTO by tracing a specially designed reentry trajectory. After the purpose of the mission was outlined at the last IAF symposium, the final fitting tests have been conducted in the ISAS Sagamihara Campus involving the flight model hardware. Furthermore, a series of rehearsals for recovery have been already executed. The paper describes the current mission status of the project. (C) 2003 Elsevier Ltd. All rights reserved.