Abstract
Japanese first interplanetary explorer “SAKIGAKE” and “SUISEI” were successfully launched by M-3SII rocket last year. And they achieved close encounter with comet Halley providing satisfactory scientific data. In this paper, the attitude control system of M-3SII racket is described, focusing our attention on the 1st stage robust controller design and their flight results. The M-3SII series rockets are composed of 3 stage solid motors, in which control capability is given to the 1st/2nd stages and the strap-on boosters. The control electronics is the fully digital type system, and the sophisticated control logic together with the weight and power reduction has been achieved. Thus the inherent control difficulty of solid propellant rockets has been overcome.
