A vacuum balloon could be used instead of a crane or helicopter for lifting any sort of load.
INDICATIONS
A skyhook could be tethered or free.
Tethered skyhooks could act similarly to a conventional crane, but with more freedom of movement, and could be controlled from the ground through cables in the tether.
Free skyhooks could act similarly to a helicopter. They could be controlled from the ground by radio-control.
Either type of skyhook could be unmanned.
Skyhooks might be particularly appropriate for lifting logging trees from forests, as they could eliminate logging roads and damage to other trees during falling.
Logging skyhooks should make felling safer, as trees could be completely severed at the base while the tree was under tension from the skyhook.
Development of devices and control software is possible here, with new approaches open to patenting or trade-secreting.
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