On 7/24/21, jim bell <jdb10987@yahoo.com> wrote:
The balloon could use hydrogen. [1] day electrolyzing
That's two fun energy sources (H + solar), plus buoyancy. If tethered then you're not spending much if any energy on stationkeeping, only on keeping the RF gimbal aimed at a target, or none if using omnidirectional-RF. If not tethered then you have a lot of energy expense just to keep in range of target. Are liquid hydrogen tanks light enough to replace their weight with gas volume then jettison? Not much altitude is needed to reach out 12NM with any system, so your tether might also carry whatever you need.
The water could be obtained by dessicating it out of the atmosphere with a deliquiescent dessicant, perhaps concentrated sulfuric
Reagents and catalysts would need refilled too. See about making water from atmosphere via free sun/shade/dewpoint condensation methods. Solar-day battery-night powered planes already exist, but they cost a lot more than simple balloons. https://duckduckgo.com/?q=solar+powered+24hr+plane If you're already hanging out at 12NM with a tether or base station, surely you can also just run whatever RF system you want from the boat deck that will cover that distance, no balloons or planes needed, assuming your target has matching RF gear. [1] Helium is rare non-renewable and should not be used for stupid toy balloon and zeppelin shit, it's way too valuable and needed for the next thousands years critical science research and perhaps even to get to the next habitable star systems.