Materials can be spread over a defined area from a tethered or free-moving vacuum balloon.
INDICATIONS
If the vacuum balloon is tethered, material to be spread can be pumped or carried up the tether, so the balloon needs only to support the weight of material in train.
A cropdusting balloon could be unmanned and controlled from the ground.
Delivery height, material spread pattern etc are finely variable and could be under control of a computer program.
Development of devices and control software is possible here, with new approaches open to patenting or trade-secreting.
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