LONG ENDURANCE AIRSHIP OPERATIONS USING A FREE-FLYING TETHERED AIRSHIP SYSTEM

摘要

In one example, a free-flying tethered airship system includes an upper airship adapted to tailor its lift and drag, a lower airship adapted to tailor its lift and drag, and a tether connecting the upper airship to the lower airship such that the upper airship is at least one kilometer above the lower airship. The upper airship is configured to be equiliberally buoyant, while carrying the tether, in a first altitude range. The lower airship is configured to be equiliberally buoyant in a second altitude range, the first altitude range being higher than the second altitude range. A method for stationkeeping of a free-flying tethered airship system is also provided.