solar technology may allow unmanned aerial vehicles (UAVs) to achieve continuous extremely low earth orbit (ELEO) or very low earth orbit (VLEO). The correct defintion of depends on altitude and whether powered flight would be considered orbiting or circumnavigating the planet.
The wing span would be very long to accomodate the solar cells needed for the prop engine and for very high altitude flight. a large aircraft such as a 747 could be used to carry it to launch altittude with the UAV wings supported by pylons at the wing tips of the 747.
such a craft could be used to monitor climate conditions at the poles or any where else on the planet. Its usefulness as a recon UAV would depend on international law and the ability of the other side to shoot it down