https://www.yahoo.com/news/airbus-backs-glider-setting-sights-stratosphere-230504224.html?nhp=1

https://www.yahoo.com/news/perlan-2-glider-airbus-claims-mantle-space-pioneer-195042208.html?nhp=1

The glider, with a wing span of 90 feet and a weight of only 1,800
pounds (815 kilograms), is designed to ride updrafts to an altitude of up to
90,000 feet, even though air density at that height is only two percent what it
is at sea level.

Thanks to Brad and Steve.