02-02-2014, 06:49 AM
I think he's using helium with his prototypes because of convenience. Kytoon arrangements are present in the patents.
The last one has several serious disadvantages in current RL, although with OA technology some of them could be minimized. The tether must be conductive, which right now means using relatively heavy electrically conductive materials like aluminum and copper, which limits the flying altitude as the tether gets longer and too heavy to fly. But carbon nanotubes are one of the best electrical conductors known. It's a UAV, with all the complexity (cost, and failure modes) of a flying machine.
The last one has several serious disadvantages in current RL, although with OA technology some of them could be minimized. The tether must be conductive, which right now means using relatively heavy electrically conductive materials like aluminum and copper, which limits the flying altitude as the tether gets longer and too heavy to fly. But carbon nanotubes are one of the best electrical conductors known. It's a UAV, with all the complexity (cost, and failure modes) of a flying machine.