Largest balloon with a human on board

The balloon that Felix Baumgartner used during the Red Bull Stratos Mission above New Mexico, USA, on 14 October 2012, had around 5,097 m³ (180,000 ft³) of helium inserted into it by the crew prior to launch. This was enough helium for lift off, but did not fill the balloon envelope to capacity because space needed to be left to allow helium to expand while the balloon rose. As the air pressure decreased with the balloon's rising altitude, the helium inside it expanded, eventually filling the entire envelope to its full, record-breaking capacity of approximately 850,000 m³ (30 million ft³) at jump altitude. The helium-filled balloon took Felix on his 38,969.4-m (127,852-ft) journey, lasting over two hours, into the stratosphere.

After several postponements due to weather, skydiver Felix Baumgartner (Austria) and the Red Bull Stratus project finally entered the annals of history on 14 October 2012 when Baumgartner skydived from a balloon from the edge of space, breaking the sound barrier in freefall and eight world records that had survived 52 years. He was aided by the man whose records he took, Col Joseph Kittinger (USA), now aged 84. The skydive was also a giant leap for online viewing: with over 8 million concurrent viewers it broke the previous YouTube record of “approximately half a million”. The build-up was well orchestrated; the very real danger was emphasized by the “live” broadcast having a built-in delay, allowing the public to be spared a gruesome spectacle in the event of tragedy. It seemed the world was united in sharing the excitement and adventure of the death-defying leap. After a tension building 2.5-hour ascent, we heard Baumgartner’s laboured voice running through the check list with Col Kittinger and telling of his visor demist failure, and we watched him depressurize the capsule and clamber through the open door to sit on the step, on the edge of space. The view was captured by numerous cameras, allowing the world - for probably the first time - to share and “take part” in this modern adventure and see him stepping off, falling away rapidly, developing an initially uncontrollable violent spin and recover control - all blind due to his visor demister failure. He continued the freefall and, after some four minutes, deployed his parachute earlier than planned given his lack of visibility. He had broken eight world records and had missed a ninth by pulling his parachute just 16 seconds too early.

Felix Baumgartner passed away on 17 July 2025. Alongside this record he also achieved a number of incredible feats, including the fastest speed in freefall and being the first human to break the sound barrier in freefall.