▁man eu ver able , ▁but ▁also ▁less ▁stable , ▁and ▁possibly ▁un stable ▁enough ▁so ▁as ▁to ▁be ▁impossible ▁to ▁fly . ▁The ▁moment ▁arm ▁of ▁the ▁elev ator ▁will ▁also ▁be ▁reduced , ▁which ▁makes ▁it ▁more ▁difficult ▁to ▁recover ▁from ▁a ▁st alled ▁condition . ▁ ▁For ▁hel ic op ters ▁in ▁hover , ▁the ▁center ▁of ▁mass ▁is ▁always ▁directly ▁below ▁the ▁rot or head . ▁In ▁forward ▁flight , ▁the ▁center ▁of ▁mass ▁will ▁move ▁forward ▁to ▁balance ▁the ▁negative ▁pitch ▁tor que ▁produced ▁by ▁applying ▁cy clic ▁control ▁to ▁prop el ▁the ▁hel ic opter ▁forward ; ▁consequ ently ▁a ▁cru ising ▁hel ic opter ▁f lies ▁" n ose - down " ▁in ▁level ▁flight . ▁ ▁Astronom y ▁▁ ▁The ▁center ▁of ▁mass ▁plays ▁an ▁important ▁role ▁in ▁astronom y ▁and ▁ast ro physics , ▁where ▁it ▁is ▁commonly ▁referred ▁to ▁as ▁the ▁b ary center . ▁The ▁b ary center ▁is ▁the ▁point ▁between ▁two ▁objects ▁where ▁they ▁balance ▁each ▁other ; ▁it ▁is ▁the ▁center ▁of ▁mass ▁where ▁two ▁or ▁more ▁cel est ial ▁bodies ▁orbit ▁each ▁other . ▁When ▁a ▁moon ▁or bits ▁a ▁planet , ▁or ▁a ▁planet ▁or bits ▁a ▁star , ▁both ▁bodies ▁are ▁actually ▁orbit ing ▁a ▁point ▁that ▁lies ▁away ▁from ▁the ▁center ▁of ▁the ▁primary ▁( lar ger ) ▁body . ▁For ▁example , ▁the ▁Moon ▁does ▁not ▁orbit ▁the ▁exact ▁center ▁of ▁the ▁Earth , ▁but ▁a ▁point ▁on ▁a ▁line ▁between ▁the ▁center ▁of