H-II launch vehicle development status in terms of vibration, shock and acoustic

Abstract

This paper describes the H-II launch vehicle's development status from the stand points of vibration, shock and acoustic (V.S.&A.) environments. The National Space Development Agency of Japan (NASDA) has been developing an indigenous launch vehicle with the philosophy of low costs and high reliability. The structural systems design and development of the H-II's are approaching its goal based on a new concept of Mechanical Environments Configured Launch Vehicle ( MECLV ) and this concept has contributed the H-II to achieve low costs and high reliability in terms of V.S.&A.. This contribution is based on the discipline that structural design of the H-II should attempt to restrict inflight mechanical environments for its components under the expected levels. To reduce development costs will require shorter development period and relaxation of design requirements. The shorter development period will be attained by means of parallel development of the components and major systems of the vehicle. For this purpose, the design requirements for the equipments to be developed had been established prior to completion of the H-II's structural detail design. And the H-II structural design and equipments installation design have been required to get milder mechanical environments than those of the H-I's. The H-II has resulted in MECLV.