Well, matey, t' rocket fell off t' nose cone. Well, blow me down! Blimey! Reason. Blimey! Blimey! Altimeter knocked around in t' tube so much that it untied a double knot. Begad! Blimey! That be t' only explanation because we double-checked t' knot before we put t' altimeter inside on t' nose cone. Avast, me proud beauty! Blimey! This is a reason never t' tie your altimeter t' a ripcord.