100,000 ft is common for a high altitude balloon, but 100km is too high. The world record for an uncrewed balloon is around 50km. https://www.space.com/41791-

100,000 ft is common for a high altitude balloon, but 100km is too high. The world record for an uncrewed balloon is around 50km. https://www.space.com/41791-giant-nasa-balloon-big-60-breaks-record.html https://www.space.com/41791-giant-nasa-balloon-big-60-breaks... https://en.wikipedia.org/wiki/Flight_altitude_record#Uncrewed_gas_balloon https://en.wikipedia.org/wiki/Flight_altitude_record#Uncrewe...