High Quality Content by WIKIPEDIA articles! Osoaviakhim-1 was a record-setting, hydrogen-filled Soviet high-altitude balloon designed to seat a crew of three and perform scientific studies of the Earth`s stratosphere. On January 30, 1934, on its maiden flight which lasted over 7 hours, the balloon reached an altitude of 22,000 metres (72,000 ft). During the descent the balloon lost its buoyancy and plunged into an uncontrolled fall, disintegrating in the lower atmosphere. The three crew members, probably incapacitated by high g-forces in a rapidly rotating gondola, failed to bail out and were killed by a high-speed ground impact.