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Confused. There seem to be plenty of drones that can stay up there for 120 hours or so [1]. Presumably, their solar additions should be able to do even more? [

Confused. There seem to be plenty of drones that can stay up there for 120 hours or so [1]. Presumably, their solar additions should be able to do even more? [1]: http://www.airforce-technology.com/features/featurethe-top-10-longest-range-unmanned-aerial-vehicles-uavs/ http://www.airforce-technology.com/features/featurethe-top-1...

pdelbarba 9y ago
Precisely. This is an incredibly easy problem to solve. See all the Rutan projects, the model plane that crossed the atlantic, etc; most from over a decade or more ago. They claim that solar efficiency is not there yet, but look at the NASA Helios. Yes, it's large, but such is life if you want solar. The math behind it is incredibly simple. Yet, as usual, HN is foaming at the mouth because it has the word drone in the title. Edit: this is just another MIT fluff piece. Watch the video, it's a carbon fiber tube filled with random COTS hobby grade components. With a hot wire and some composites knowledge you could make this in your garage.
- lochieferrier 9y ago
  NASA Helios was quite expensive and tricky to build, with not a lot of margin left for useful payload. There's a weight runaway that occurs with solar powered aircraft, look at Fig 12 in this report: http://hoburg.mit.edu/publications/gassolar.pdf http://hoburg.mit.edu/publications/gassolar.pdf Disclaimer: I worked on this project, so am super biased.
  - pdelbarba 9y ago
    I'm aware, I agree that solar aircraft is not an easy technology. I'm mostly pointing out how inane this gasoline drone project is when there are real problems to solve. To put it in perspective, the Helios project was 18 years ago and the Solar Impulse project improved upon the tech significantly. Edit: just got a chance to look at the report. Thanks for the link, there are some really interesting findings in there.
  - throwawaycrank2 9y ago
    Please read the next four paragraphs. Could you kindly reply with your email, as I would like to email you. I am a crank inventor (no but keep reading, just three and a half more paragraphs!) who has invented something similar to a free-energy machine, except in the field of aviation and specifically renewable energy flight, where free power is in the skies for anyone so it's not totally cranky. After all you just wrote a 27-page draft about it. (By the way your paper is very solid and prominently describes in detail several trade-offs that I address specifically through a different mechanism; you are the real deal.) I would like to work with a collaborator (such as yourself) and then patent and license the technology. Specialist patent offices I contacted said that they would have a conflict with their existing large clients Boeing etc, and for this reason cannot work with me. On the other hand if they do not have this experience it is kind of a catch-22. Your personal resources and if appropriate (if it works) your resources at MIT would alleviate this issue. We can discuss the rest by email. I look forward to your reply. It will not take much of your time to make a determination. I promise it will be interesting and well-specified (usually crank inventors misuse common terminology, don't correctly understand the principles they use, and are vague and underspecified, committing logical errors and non-sequiturs to arrive at their mechanism - this isn't like that.) Thank you!
    - andygates 9y ago
      ...novel crank pitch, but just throwing it into a random discussion thread is fatal. It's already almost downvoted into oblivion. Show a prototype working, or people will (usually correctly) assume you're a scam or a kook.
      - throwawaycrank2 9y ago
        it just got one downvote (maybe before I finished writing it as I was editing it) so it's all right. I don't think there's anything wrong with reaching out for a contact via a HN thread. I'd specifically like to reach Lochie due to their comments here. (For example, no offense, but I'm not really soliciting your thoughts, andygates.) By the way I also found that Lochie (who I think I made a mistake and wasn't a coauthor of the paper they linked - I was thrown off by "I worked on this project"), reviewed another person's alternative scheme, so I'm doubly convinced they're the right person to quickly review my work. -> Lochie, in the meantime I actually did find your email (I just wasn't looking that hard I guess). Do you mind if I email you briefly? Thank you!
- walrus01 9y ago
  > Yes, it's large, but such is life if you want solar. also incredibly fragile, with regards to crosswinds and takeoff/landing environmental conditions.
  - resu_nimda 9y ago
    Say, what happened to that Helios again? https://en.wikipedia.org/wiki/Helios_Prototype#/media/File:Pages_from_64317main_helios-2.jpg https://en.wikipedia.org/wiki/Helios_Prototype#/media/File:P... Helios disintegrates as it falls towards the Pacific
    - ge96 9y ago
      what I had no idea... awe poor thing gotta find out what happened to it why it just broke up, also despite a flying wing being more efficient with regard to drag, why a plank? Don't they need more reflex with a shorter moment arm... anyway shit edit: weather
  - pdelbarba 9y ago
    Let's just say the tech has progressed somewhat since the 90s. https://en.wikipedia.org/wiki/Solar_Impulse https://en.wikipedia.org/wiki/Solar_Impulse

pdelbarba 9y ago

Precisely. This is an incredibly easy problem to solve. See all the Rutan projects, the model plane that crossed the atlantic, etc; most from over a decade or more ago. They claim that solar efficiency is not there yet, but look at the NASA Helios. Yes, it's large, but such is life if you want solar. The math behind it is incredibly simple. Yet, as usual, HN is foaming at the mouth because it has the word drone in the title. Edit: this is just another MIT fluff piece. Watch the video, it's a carbon fiber tube filled with random COTS hobby grade components. With a hot wire and some composites knowledge you could make this in your garage.

lochieferrier 9y ago
NASA Helios was quite expensive and tricky to build, with not a lot of margin left for useful payload. There's a weight runaway that occurs with solar powered aircraft, look at Fig 12 in this report: http://hoburg.mit.edu/publications/gassolar.pdf http://hoburg.mit.edu/publications/gassolar.pdf Disclaimer: I worked on this project, so am super biased.
- pdelbarba 9y ago
  I'm aware, I agree that solar aircraft is not an easy technology. I'm mostly pointing out how inane this gasoline drone project is when there are real problems to solve. To put it in perspective, the Helios project was 18 years ago and the Solar Impulse project improved upon the tech significantly. Edit: just got a chance to look at the report. Thanks for the link, there are some really interesting findings in there.
- throwawaycrank2 9y ago
  Please read the next four paragraphs. Could you kindly reply with your email, as I would like to email you. I am a crank inventor (no but keep reading, just three and a half more paragraphs!) who has invented something similar to a free-energy machine, except in the field of aviation and specifically renewable energy flight, where free power is in the skies for anyone so it's not totally cranky. After all you just wrote a 27-page draft about it. (By the way your paper is very solid and prominently describes in detail several trade-offs that I address specifically through a different mechanism; you are the real deal.) I would like to work with a collaborator (such as yourself) and then patent and license the technology. Specialist patent offices I contacted said that they would have a conflict with their existing large clients Boeing etc, and for this reason cannot work with me. On the other hand if they do not have this experience it is kind of a catch-22. Your personal resources and if appropriate (if it works) your resources at MIT would alleviate this issue. We can discuss the rest by email. I look forward to your reply. It will not take much of your time to make a determination. I promise it will be interesting and well-specified (usually crank inventors misuse common terminology, don't correctly understand the principles they use, and are vague and underspecified, committing logical errors and non-sequiturs to arrive at their mechanism - this isn't like that.) Thank you!
  - andygates 9y ago
    ...novel crank pitch, but just throwing it into a random discussion thread is fatal. It's already almost downvoted into oblivion. Show a prototype working, or people will (usually correctly) assume you're a scam or a kook.
    - throwawaycrank2 9y ago
      it just got one downvote (maybe before I finished writing it as I was editing it) so it's all right. I don't think there's anything wrong with reaching out for a contact via a HN thread. I'd specifically like to reach Lochie due to their comments here. (For example, no offense, but I'm not really soliciting your thoughts, andygates.) By the way I also found that Lochie (who I think I made a mistake and wasn't a coauthor of the paper they linked - I was thrown off by "I worked on this project"), reviewed another person's alternative scheme, so I'm doubly convinced they're the right person to quickly review my work. -> Lochie, in the meantime I actually did find your email (I just wasn't looking that hard I guess). Do you mind if I email you briefly? Thank you!
walrus01 9y ago
> Yes, it's large, but such is life if you want solar. also incredibly fragile, with regards to crosswinds and takeoff/landing environmental conditions.
- resu_nimda 9y ago
  Say, what happened to that Helios again? https://en.wikipedia.org/wiki/Helios_Prototype#/media/File:Pages_from_64317main_helios-2.jpg https://en.wikipedia.org/wiki/Helios_Prototype#/media/File:P... Helios disintegrates as it falls towards the Pacific
  - ge96 9y ago
    what I had no idea... awe poor thing gotta find out what happened to it why it just broke up, also despite a flying wing being more efficient with regard to drag, why a plank? Don't they need more reflex with a shorter moment arm... anyway shit edit: weather
- pdelbarba 9y ago
  Let's just say the tech has progressed somewhat since the 90s. https://en.wikipedia.org/wiki/Solar_Impulse https://en.wikipedia.org/wiki/Solar_Impulse