Medal commemorating first free balloon stratospheric flight of Professor Auguste Piccard (1884-1962) and Dr. Paul Kipfer, in balloon FNRS, from Augsburg in Germany, 27 May 1931. Silver; 36mm diameter, 2mm thickness. Rim: Bayer. Hauptmunzamt. Feinsilber. [Bavarian State Mint]. Obverse: Professor A. Piccard - Dr. P. Kipfer. Double portrait, full heads facing front, looking slightly to right. Artist signed beneath: K. Goetz. Reverse: legend: Stratospharenflug. mit Riedinger. Freiballon. 15,781 m[etres]. 27. V. 1931. Start Avgsbvrg. ; scene: balloon above clouds, over cityscape of Augsburg. Piccard designed a spherical, pressurised aluminium gondola allowing ascent to great altitude without requiring a pressure suit; he gathered much data on the upper atmosphere and studied cosmic rays; the first of 27 balloon flights