Drooo

Slightly less than 80 km high

Around 80 KM, which is the same as what the U.S. considers when space begins. The whole world considers 100 KM, or the Kármán Line for when space begins.

78 km for the current versions

Well the measurable atmosphere (where the gauge in the info panel begins to register at 0.01 m/g) is around 78,200 meters! You can verify this by observing a craft on reentry
……
But there is definitely still atmosphere above that point (observable through orbital decay that happens to objects around Droo). Ive observed orbital decay on satellites up to at least 730 km as well as what seem to be slight changes in an orbit once a craft gets 1200-1000 km from Droo. Once a craft is above 2000 km it seems all atmospheric effects cease.

As far as I know 80km