Patent ID: 8267348

Claim:
Unmanned aircraft stationable at a pre-determined altitude in the stratosphere, comprising: a platform for telecommunications equipment or scientific equipment, an outer balloon having an aerodynamic external shape at least when present in the stratosphere, a pressurized balloon which is fillable with gas and that supports the platform, the pressurized balloon being arranged within the outer balloon such that the outer balloon forms at least one insulating chamber around the pressurized balloon, the insulating chamber being fillable with a medium that circulates therethrough, heating and cooling means for heating and cooling the medium circulating in the insulating chamber, and position maintaining means located outside the outer balloon for maintaining the position of the platform relative to the Earth, the heating and cooling means comprising a heating unit and a cooling unit configured to heat and cool, respectively, the medium circulating through the insulating chamber, the heating unit and cooling unit being configured to operate alternately and both being arranged outside of the outer balloon.