T' real Frangible Arrrrrrrcas was an experimental variation o' t' Arrrrrrrcas soundin' rocket and be launched four times betwixt 1964 and 1965. Well, blow me down! Aye aye! It be designed t' fragment after payload separation, arrr, matey, me hearties, reducin' t' risk t' populated areas from a fallin' spent rocket motor.