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Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

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171–180 of 206 posts

Re: Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

#171
post #10

Wow, 10cm live view for complete situational awareness of forest fires feels like it should be a game changer. Can we make sure someone (if not you guys) fully builds this service on your flights for the fire service?

Why does forest fires need 10cm resolution? I'm fairly familiar that space (in Australia though) and I've never heard that requirement.

There are other fields where 10cm resolution is required though, obviously.

Re: Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

#172

Very interesting! This sounds a lot like the more recent iterations of the Airbus Zephyr: https://en.wikipedia.org/wiki/Airbus_Zephyr I don't know how much you can share, but I'm curious about the solar and battery system. Are you using silicon cells, multi-junction cells, or something else? What sort of battery chemistry do you use? It seems like deep battery cycling is a must to keep weight under control, but batte…

Yes, Airbus’s project and team is very cool! What we’re doing shares similarities with Zephyr, but we’re focusing on a lower cost system, and a larger payload which will enable more use cases. We’re using conventional silicon solar cells, rather than the GaAs cells used by Airbus. We give up some efficiency by doing this, but it keeps costs far lower - which we think is key to iterating quickly, and opening up some o…

> we’re focusing on a lower cost system, and a larger payload which will enable more use cases.

So you want to beat Airbus but also be cheaper. And do it with off-the-shelf components too, because those specialized ones are just too expensive. Not to say it's impossible but wow

Re: Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

#173

Earlier quoted context omitted.

I am possibly wrong about small details, and would appreciate corrections. So when I joined the project, the physical aircraft was based in the USA, but the software team for the autopilot was based in the UK. For some reason - I think it was the very high altitude capability - the USA considered the autopilot to be munitions. When I first joined the project, there was this bizzare situation where it turned out to be…

Re' sending an entire aircraft over the ocean vs. sending software over the internet: you'd be surprised, but it's still often the case. I worked for a storage company that made a long-distance replication product (i.e. a program that allows one to store their data both locally and far away in a reasonable time-frame). We were contacted at some point by a movie production company which had this problem of moving the…

I don't think the size of the update was the issue here.

I guess it's something like the US Export control systems for arms, but for imports? I'd love to know the details of what legislation it was under - possible it was on the UK side.

Re: Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

#174
Awesome guys. I had a poster of Helios on my wall growing up. I'd be curious to know more about the construction. 13 lbs for a first prototype is pretty good. I have a 4'x25' autoclave, so if there's anything I can do to help, let me know! I mostly make 16 lb canoes, but have lots of extra machine time. The only problem, I am in Hawai'i. :)

Re: Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

#175
post #164

Earlier quoted context omitted.

The standard story arc for something like this is that it is pitched as a humanitarian/environmental technology, but it is the military that provide the money and that where it gets used. I'm not being overly judgemental - the good guys (e.g. Ukraine) need good military tech. But lets not kid ourselves.

Basically any technology that makes any difference will have a military value, and will be used by the military. One of the few things that are not obviously, if in any way at all, usable for any military purposes is targeted advertising. Whether it's used by the good guys more is an interesting topic.

That's not actually true about ad targeting. The tech used there is a big information warfare thing, which has major military applications

Re: Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

#176
post #165

How does the aircraft get to 70k feet? Is it launched from a separate vehicle?

I suppose an aircraft like this can climb like gliders do, using the streams of air that move upwards. This requires some planning, and likely a skilled glider pilot to help choose the course.

I'm not an expert but I don't think thermals rise that high.

Re: Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

#177
post #49

Earlier quoted context omitted.

I'm similarly curious. Designing for a higher stall speed permits smaller wing area, lower drag, and lower weight. The cost is that takeoffs and landings become troublesome.

Could be catapult launched?

Or balloon launched, parachute landing.

Re: Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft

#180
post #165

Earlier quoted context omitted.

I suppose an aircraft like this can climb like gliders do, using the streams of air that move upwards. This requires some planning, and likely a skilled glider pilot to help choose the course.

I'm not an expert but I don't think thermals rise that high.

They could help the first few kilometres, where the air density and thus the drag are highest.
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