Non-poroussoundabsorbersaremoredesirablethanconventionalporousonestomitigateacousticloadingsinside
launcher fairingsbecausetheydonotraiseparticlesofdustandmaintainthestrictcleannessofinteriorspace.Inthis
regard,themicro-perforatedpanelabsorbers(MPPA)canbeagoodcandidateforthereductionofnoiseinsidelauncher
fairings [1]. Inordertoincreasethesoundabsorptionbandwidth,someimprovedarrangementmethods,forexample,the
double layerofMPPA [2–4] and thearrayofMPPAswithdifferentcavitydepth [5] havebeenproposed