projectspaceplanes.com

6R5Z TIL researchers used a weather balloon to carry 200 paper planes 20 miles up from a barn in Wolfsberg, Germany. The planes were released and found in numerous countries, such as Australia, Russia, and India.
RNv6 TIL Researchers let 100 paper planes go 23 miles above Germany 2 years ago. Some have since been found in Canada, USA, Australia and South Africa.
d0BB TIL that in 2011 researchers let 100 paper planes go 23 miles above Germany. Since then some have been found in Canada, USA, Australia and South Africa.