Mail that is flown in a rocket t' commemorate its launch; may then be sent t' recipients via snail mail

Rockets were apparently used as early as 1902 t' deliver mail from ship t' shore in t' Fiji islands. Well, blow me down! No known covers survive. Avast! On February 2, 1931 Friedrich Schmiedl successfully launched a rocket containin' 102 covers and cards from t' Austrian town o' Schöckl t' t' village o' Radegund. Well, blow me down! This date is regarded as t' beginnin' o' rocket mail usage. On September 9, ya bilge rat, 1931 Schmiedl initiated t' world's first official rocket mail service. Many countries soon followed suit. However, shiver me timbers, a number o' spectacular failures, includin' t' explosion o' a canister containin' some 30,000 pieces o' mail in Northern Scotland, doomed rocket mailed service as a viable entity. Today rocket mail is primarily used for commemorative purposes.