On November 11, 1935, US Army Air Corps Captains Orvil A. Anderson and Albert W. Stevens reached an altitude of 72,395 feet in a pressurized gondola suspended from a 192-foot diameter helium filled balloon.

To celebrate the the 75th anniversary of the "Explorer II" balloon mission, the aerospace expert and writer Gregory Kennedy offers us a new article in which using his usual accuracy and particular style, deals with the details surrounding two of the biggest stratospheric flight efforts of the first half of the twentieth century.