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Solar-powered aircraft flown for nearly three weeks without landing

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Re: Solar-powered aircraft flown for nearly three weeks without landing

#91

Post by Fiahil »

Retric wrote: post #56
Tepix wrote: post #34

Earlier quoted context omitted.

Why wouldn't you use the wind energy also? It's a lot of fun, readily available and a lot cheaper…

Sails have several major downsides, most notably they take up a lot of deck space and cause a boat to tilt to the side. If you’re regularly sailing long distances it’s much faster but top speed isn’t that big of a deal when your living on the boat full time. Other options like kites and wind turbines can work well but they all all significant upfront costs as well as ongoing maintenance issues. Spending that same mon…

> Sails have several major downsides[..]

Yes, but it makes less noise.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#92

Post by bentcorner »

detritus wrote: post #36
GhostVII wrote: post #26

What's the benefit over something like a weather balloon? Pretty interesting thought, tape a few hundred micro SD cards to it and you've got some impressive bandwidth.

You can tell this where to go - weather balloons are utterly beholden to the whim of wind patterns.

¿Por qué no los dos?

It looks like solar-powered zeppelins are a thing, although with the brief googling I did it looks like nothing really exists just yet.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#93

Post by GhostVII »

detritus wrote: post #36
GhostVII wrote: post #26

What's the benefit over something like a weather balloon? Pretty interesting thought, tape a few hundred micro SD cards to it and you've got some impressive bandwidth.

You can tell this where to go - weather balloons are utterly beholden to the whim of wind patterns.

Yea I guess I was more thinking of a kind of blimp, where it still has some solar to allow it to maneuver around, but not to actually stay up.

If the aircraft needs to stay in one place maybe that would be less efficient though, since it would be harder to fight winds.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#94

Post by OJFord »

j245 wrote: post #78
OJFord wrote: post #16

Earlier quoted context omitted.

Is it not? I don't imagine such sustained flight, continuous operation of all the equipment and engine for so long, would've been a design consideration. Presumably there's a number, I just doubt it's tens of days, so isn't it interesting that it was achieved?

This record was set ~3 months after someone else did it for 50 days. From an engineering stand point, performance of components or materials are always assumed to be much worse than actual and the forces / conditions they are subject to overestimated, with further factors of safety applied on top. This is how it should be. It also means properly designed things will carry on working better than you expect (on average…

> This record was set ~3 months after someone else did it for 50 days.

Fair enough, I didn't know about that, I'd have been as interested to hear about either of them first, and like you not so much the other second. (And I doubt the commenter that shared it meant it as 'wow look 64 compared to 50' either.)

Re: Solar-powered aircraft flown for nearly three weeks without landing

#95

Post by Ottolay »

ethbr0 wrote: post #88
runarberg wrote: post #72

Earlier quoted context omitted.

I’m a bit puzzled by the economy here. Is creating, lunching and orbiting a satellite really cheaper then flying an airplane? Is it really cheaper to have a decommissioned satellite totally burn up in the atmosphere then reusing parts of an airplane to fix another, recycle unusable parts and put the rest in a landfill? The economics here just seem wrong.

USD2021$15M per Falcon 9 launch (re-used, assuming first launch was paid for by a customer) [0] 60 Starlink satellites per Falcon 9 launch [1] = + USD2021$250,000 in launch costs per satellite (+ manufacturing / ops costs) [0] https://www.elonx.net/how-much-does-it-cost-to-launch-a-reus... [1] https://space4peace.org/starlink-gears-up-to-launch-nearly-1...

As a reference a new Cessna 172 is $432,000 [1] and that is not a high tech aircraft.

[1] https://www.forbes.com/sites/erictegler/2021/04/28/prices-fo...

Re: Solar-powered aircraft flown for nearly three weeks without landing

#96

Post by rlt »

tpmx wrote: post #23

Probably/unfortunately not really a Starlink competitor, right? They don't specify the "cruising" altitude, but I assume it's ~10 kilometers at most, probably less? Airbus would need quite a few of these in order to build a global internet connectivity service then. Edit: https://en.wikipedia.org/wiki/Airbus_Zephyr says ~20 km. Starlink sats (will) operate at ~540-570 km: https://spaceflightnow.com/2021/04/29/spacex-…

They would have the advantage of variable density based on demand, i.e. more of them over population centers and none over oceans, whereas LEO satellite constellations are pretty uniformly distributed because they're orbiting.

It's sort of in between a stationary cell tower and LEO satellite constellation.

But then you have to worry about them failing and hitting those population centers, whereas satellites deorbit slowly and usually burn up completely.

Re: Solar-powered aircraft flown for nearly three weeks without landing

#97

Post by agustif »

mariusseufzer wrote: post #86
rektide wrote: post #71

Earlier quoted context omitted.

anyone else think it would be super damn fun building solar floating homes like this?

I'd be down haha - When do we start?

If sea levels keep rising a lot of coasting could be like this.

In the netherlands they have flaoting houses in the canals, but stationary AFAIK

Re: Solar-powered aircraft flown for nearly three weeks without landing

#98

Post by bserge »

mariusseufzer wrote: post #86
rektide wrote: post #71

Earlier quoted context omitted.

anyone else think it would be super damn fun building solar floating homes like this?

I'd be down haha - When do we start?

There's a couple living on a cheap ass floating tent/home (it literally uses barrels to float) in Sweden I think. Pretty cool. Also narrow boats in England are cheap and rather nice. Could start there.

https://youtu.be/jljkK9HMa44

Re: Solar-powered aircraft flown for nearly three weeks without landing

#99

Post by Ottolay »

elif wrote: post #65
Ottolay wrote: post #46

Earlier quoted context omitted.

The U2 operated at over 20km, so maybe the altitude is higher. I suspect the greater issue is vehicle cost, lifetime, and safety. A starlink satellite is much smaller (and as result cheaper) and is rumored to have a 5+ year lifetime. Also, at end of life it burns up in the atmosphere. No worry about pushing the life on a component and having it crash and kill someone as a result.

Glide based efficiency crafts absolutely need thick atmosphere. They don't have supersonic jets.

The U2 was subsonic. Also, un-powered gliders can get up to impressive altitudes.

https://www.airbus.com/newsroom/press-releases/en/2018/09/ai...

Re: Solar-powered aircraft flown for nearly three weeks without landing

#100

Post by mattlondon »

stareatgoats wrote: post #24

This is great and points to how solar in some cases already can facilitate continuous operation without the need for refueling of planes, boats, cars, you name it. Expect this to grow as battery and solar cell tech develops further. My favorites atm are the yachts that are capable of sailing just about anywhere in the world without a drop of fuel. The price is prohibitive, but considering that you might not need a ho…

I've always been kinda fascinated by this solar yacht concept.

I wonder now with post-covid remote working options and starlink if you could actually make it work.

I do wonder though if sailing the ship is basically a full-time job in itself (navigation channels? Docking at foreign countries? Getting food etc?).

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