The first-of-its-kind demonstration was conducted using a small Cessna aircraft to simulate the eventual use of High-Altitude Platform Stations (HAPS).
Source (and read more):
The first-of-its-kind demonstration was conducted using a small Cessna aircraft to simulate the eventual use of High-Altitude Platform Stations (HAPS).
Source (and read more):
Japan had probably already developed this technology, in addition to showing the technological capacity.
I believe it is a demonstration of defense against Korea.