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

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91–100 of 206 posts

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

#91
post #65

Daniel, from RCTESTFLIGHT on YouTube, has a series of videos where he experiments with solar airplanes, which wad really interesting to watch from the standpoint of a RC and electronics hobbyist: https://youtube.com/playlist?list=PLXvxJNOIXBsM83XxVG7tDUmql...

Yeah Daniel made some really cool solar aircraft and other RC stuff! Love his channel. We talked to him in the early days of this project.

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

#92
post #76
post #21

So YC is getting into defense contracting now?

Fascinating reaction. It's not surprising but it is nonetheless disappointing.

Maybe they should be working on reliable management of multiple HN accounts.

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

#93

Didn’t Facebook pursue this idea also? Do you know the details and why they didn’t end up succeeding? https://www.theverge.com/a/mark-zuckerberg-future-of-faceboo...

I worked on this at Facebook very briefly. I believe the project was called Aquila internally. I worked with a famous engineer who joined Facebook from a well known british aircraft manufacturer. He was an aerodynamics expert and was trying to solve the problems of flutter and other dynamic instability in the extremely large, high aspect ratio, lightweight composite wing. I wasn't officially told this, but I believe…

> I have some pretty crazy anecdotes to share about the project if anyone is interested?

I am! Please do share!

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

#94
Stop. This is not a valid startup and a waste of your time.

I say this with a heavy heart as I know you're passionate, but numerous failed startups of my own tought me to be critical in thinking.

What is you're "secret sauce"? How hard is it to replicate/exceed your efforts? I'm afraid the answers are "we put a lot of engineering work into it" and "not much, as we're just two guys and the army/google/fb have hundreds of engineers", and you're limited by physics. It's not like you invented new super-light batteries, did you?

I'm afraid this will likely be a waste of your time. You'll have fun, learn a lot, and that can be a goal on its own, But don't take a mortage....

sorry..

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

#95

Didn’t Facebook pursue this idea also? Do you know the details and why they didn’t end up succeeding? https://www.theverge.com/a/mark-zuckerberg-future-of-faceboo...

I worked on this at Facebook very briefly. I believe the project was called Aquila internally. I worked with a famous engineer who joined Facebook from a well known british aircraft manufacturer. He was an aerodynamics expert and was trying to solve the problems of flutter and other dynamic instability in the extremely large, high aspect ratio, lightweight composite wing. I wasn't officially told this, but I believe…

I'm interested.

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

#97

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

The aircraft is able to climb under its own power. We have a diurnal energy cycle - charging the battery up through the day and deploying battery energy in the night. If we launch in the morning with a full battery, we have a whole day's worth of extra solar power to use to climb up to altitude. Winds will be a bigger issue than energy when climbing. Up at 20 km (70k ft.) winds are quite calm, but we need to ascend t…

Winds up to 20 km are NOT quite calm. They can max out to 60 m/s at height of 10 km, which is more than 3 times than enough to blow a solar aircraft far-far away. You have to choose proper meteo conditions for climbing and descending and plan the trajectory taking into account those winds to be able to land at a given place. I've been analyzing GFS data a couple of years ago for similar project. The problem is that lack of energy demands to design a really low speed aircraft for low densities that you can find in stratosphere. At 10 km winds are stronger than in stratosphere and density is higer. You can find the results in https://journals.sagepub.com/eprint/GVXWXDABPE6A8PNRGTBU/ful.... The whole aircraft model probably is not like yours and is subject to many conservative estimates, but I am pretty much sure that wind model is accurate in this publication and generalizable to different regions.

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

#98
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?

Wildland forest fires were actually the inspiration for this technology! A year ago Seattle had the worst air quality in the world for a few days, which piqued my interest in the area. Speaking to people in the USFS we learned about the challenges of getting real-time high-resolution data, and realized that an ultra long endurance drone would be a great way to get this.

Any idea how big an effect air quality has on cell efficiency? Do cells work with diffuse light or is 20km high enough to be unaffected?

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

#99

Stop. This is not a valid startup and a waste of your time. I say this with a heavy heart as I know you're passionate, but numerous failed startups of my own tought me to be critical in thinking. What is you're "secret sauce"? How hard is it to replicate/exceed your efforts? I'm afraid the answers are "we put a lot of engineering work into it" and "not much, as we're just two guys and the army/google/fb have hundreds…

This is neither constructive nor actionable. Why is this not a valid business? They already have a functional prototype which is more than most young companies in this field manage, plus a clear path of where they want to be and who their customers are. So what exactly do you see as the problem?

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

#100

Didn’t Facebook pursue this idea also? Do you know the details and why they didn’t end up succeeding? https://www.theverge.com/a/mark-zuckerberg-future-of-faceboo...

I worked on this at Facebook very briefly. I believe the project was called Aquila internally. I worked with a famous engineer who joined Facebook from a well known british aircraft manufacturer. He was an aerodynamics expert and was trying to solve the problems of flutter and other dynamic instability in the extremely large, high aspect ratio, lightweight composite wing. I wasn't officially told this, but I believe…

I would love to hear some anecdotes!
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