These balloons were developed during the earlier Projects Helios and Skyhook by Jean Piccard and Otto C. Winzen.
Otto von Bismarck | Otto | Otto III | Otto Piene | Otto I, Holy Roman Emperor | Otto I | Otto Preminger | Otto II | Otto Dix | Otto Natzler | Otto II, Holy Roman Emperor | Otto Binder | Otto Skorzeny | Otto Schenk | Otto of Brunswick | Otto Kerner, Jr. | Otto Steinbrinck | Otto Kerner | Otto IV, Holy Roman Emperor | Otto IV | Otto III, Holy Roman Emperor | Otto Braun | Miranda Otto | Frei Otto | Otto-Werner Mueller | Otto Schmidt | Otto Muehl | Otto Lilienthal | Otto Klemperer | Otto Hermann Kahn |
He stayed there to do graduate work, and in 1904 received the degree of D.Ph. His doctoral thesis was entitled Über den kannibalismus bei Fasciolaria tulipa (var. distans) und deren larvale excretionsorgane.