The Guardian: Thousands march in Cuba in rare mass protests amid economic crisis
schear.steve at gmail.com
Sun Jul 25 04:47:19 PDT 2021
The need to maintain relative station keeping without the need for tethers
or propulsion was one of the hallmarks of Loon tech.
On Sun, Jul 25, 2021, 9:40 AM jim bell <jdb10987 at yahoo.com> wrote:
> On Sunday, July 25, 2021, 01:17:03 AM PDT, grarpamp <grarpamp at gmail.com>
> On 7/24/21, jim bell <jdb10987 at yahoo.com> wrote:
> >> The balloon could use hydrogen. 
> >> 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.
> I see no need at all to do station-keeping. The balloon could simply
> detect its GPS location, and using that re-calculate what its optimum aim
> for the antenna(s). The people 'watching' the microwave signal would see
> only a slight change in azimuth., presumably not enough to require them to
> >Are liquid hydrogen tanks light enough to replace
> their weight with gas volume then jettison?
> No, that's totally impractical. That's why I suggest creating new
> hydrogen, in gas form, storing it into the huge balloon, and using a bit
> of it, at night, to generate electricity in the fuel cells. I've never
> worked with fuel cells, but I believe it's fairly simple, because the
> components already exist.
> >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.
> I don't think so. The article says that the lifetime of the balloon would
> be relatively short, was it 7 months? The dessicant (I proposed
> concentrated sulfuric acid) wouldn't evaporate, so it would never run out.
> The catalysts in the fuel cell would be essentially permanent for the life
> ot the balloon's million.
> >See about making water from atmosphere via
> free sun/shade/dewpoint condensation methods.
> I assume the altitude will be about 40-50,000 feet.
> >Solar-day battery-night powered planes already exist,
> but they cost a lot more than simple balloons.
> solar powered 24hr plane at DuckDuckGo
> That's one reason to use a hydrogen-filled balloon, doubling for life and
> fuel-cell fuel storage.
> >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.
> I don't see an obvious need for a boat. just an anchor. One big reason
> is that any boat would stick out by radar, directing the enemy Cuban
> military to try to cut the tether. I think that there could actually
> be multiple tethers, maybe even 5, tied together at perhaps 5,000 altitude,
> and each anchored at perhaps a mile apart, so that if one gets cut by a
> passing plane, the rest will take over the function.
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