This "Stratosphere Mail" cover has a printed National Geographic Society/Army Air Corps printed cachet on the front along with a July 12, 1935 Rapid City, S. D. cds. There is a printed explanation on the reverse that reads: "At the time the balloon ripped on the morning of July 12, 1935, the mail that was to have been carried on the flight had already been cancelled and stowed aboard. During the period that the balloon was being rebuilt the "covers" were stored in safe-keeping. The postmark immediately above (Nov. 11, 5 AM, Rapid City, S. D.) indicates the actual day and hour of the start of the Stratosphere Flight of Explorer II". There is an additional "White Lake Nov. 11, 4PM" hand cancel on the face indicating where the balloon landed. Minor aging but attractive. FLOWN? Yes