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

news.ycombinator.com

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

#131

Post by bbor »

pierrekin wrote: post #109
pierrekin wrote: post #80

Earlier quoted context omitted.

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…

One last thing that is a little bit sadder, so I thought I'd post in a separate thread. I grew to really like the engineer that invited me to the project. He was a well known expert in the field with a wiki page, books, academic eminence and everything, and he offered to mentor me etc. I travelled with him a few times from FB's London office to the prototyping site and he was always very generous with hotels, travel…

That's terrible, thanks for sharing. I thought I was pretty cynical, but I didn't see that coming at all -- good reminder to keep an open mind and always maintain boundaries, just in case. Also the implicit ending is sobering: he likely continues to pursue such asymmetrical relationships to this day, because "cancelling" high-level corporate workers is a lot harder than #metoo makes it seem

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

#132

Post by Aspos »

Goodroo wrote: post #123
denton-scratch wrote: post #15

This sounds like military technology of the kind that e.g. Ukraine would currently like a few samples of. Or at least, dual-use.

Would probably be shot down or hacked/jammed by the Russians in a day or two

Shooting down an airplane at 20km altitude requires an expensive rocket and reveals position of the launcher. No, can't use cheap MANPADs for this.

My gut feeling tells me this airplane is potentially cheaper than a rocket, so if it is shot down, it is a win already. If it detects launcher position while rocket is on the way it is even bigger win. Potentially it reveals larger radar position too, that's another win.

It is difficult, expensive and risky to jamm objects at that altitude. In the current Ukraine-Russia war russians would probably not bother jamming it.

So, what these guys are developing certainly is a military technology. No way around this. High endurance, high altitude cheap aircraft will sell like hot cakes.

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

#135

Post by CamperBob2 »

rolling_robot wrote: post #97
jthomaslm wrote: post #64

Earlier quoted context omitted.

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 l…

I'd assume it's like on Mars, where wind speeds are hellacious but there's just not enough 'air' mass to do any real harm.

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

#136

Post by tomcam »

pierrekin wrote: post #80
e-_pusher wrote: post #63

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…

Oh yes, we are interested!

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

#137

Post by bagels »

rolling_robot wrote: post #97
jthomaslm wrote: post #64

Earlier quoted context omitted.

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 l…

I think the comment you responded to was saying at 20km ("up at 20km") it is calm, but below this it is not calm.

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

#138

Post by bagels »

zeusk wrote: post #68
moralestapia wrote: post #59

Earlier quoted context omitted.

I don't think one could just "throw" something 70k feet up in the air.

Spinlaunch would disgree but here the trouble is getting off the ground; Take-off is the most demanding phase of flight in terms of propulsion demand.

Spinlaunch would crush any aircraft that is light enough to stay aloft indefinitely.

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

#139

Post by placesalt »

sroussey wrote: post #110
pj_mukh wrote: 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?

There are commercial sats doing this.

Not live at that resolution, AFAIK.

Planet has the spatial resolution but not the temporal resolution.

NOAA has the temporal resolution but not the spatial resolution.

Please correct me if I'm wrong.

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

#140

Post by jthomaslm »

setgree wrote: post #9

Super cool! I have purely cosmetic feedback about the website, which is that the tagline "from the stratosphere" doesn't match up with the images being played behind, which are pretty clearly low altitude. I am assuming that's because it was easier (or possible whatsoever) to film lower, but it gave me a little mental hiccup. I look forward to seeing what y'all come up with!

Thanks so much, it's a lot of fun to work on.

Thanks for the website feedback - for the sake of clarity, our test flights with the sub-scale aircraft have all been at lower altitudes. The stratosphere is the next step and we plan to fly there next summer!

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