“It’s a lot easier to send a power beam directly up or down relative to the ground because there is so much less atmosphere to fight through,” Jaffe explains. “For PRAD, we wanted to test under the maximum impact of atmospheric effects.”
Super impressive! My only complain is that this was done at the White Sounds desert in New Mexico, at over 1200 meters of elevation. For maximum impact they should have done it in Florida on a hot humid day
The application to drones seems most clear: beam drones some extra power as needed. Or continually!
I wonder how big that receiving apparatus is. Whether the receiver is gimballed, or whether the drone itself has to fly a heading to aim at the sender: TBD.
"reflects onto dozens of photovoltaic cells arranged around the inside of the device which convert the energy back to usable power."
This is no different that what we were considering two decades ago for the space elevator competition. One of the problems with this approach is that as the photovoltaic cells heat up their overall efficiency decreases.
No. 800 watts (vs megawatts for HVDC). 5 miles vs thousands of miles. 20% efficiency optical to electrical - so electrical vs electrical is much worse - vs 90%+.
This is so much worse in every aspect it's not really compareable.
This seems very silly. It's either a death ray project in a fake mustache or somebody had earmarked a bunch of money that they had to spend before it expired.
This is kinda surprising to read. I’ve never known anyone who isn’t incredibly excited at least at the prospect of wireless energy transfers. If you can do 800 watts over 8 km, surely we can do 150 watts across 3 feet in the household, and MANY of our most important discoveries come from DARPA essentially being a black budget skunkworks team.
But much of the stuff DARPA does seems weird. It’s not about ideas with solid foundation and thorough engineering, it’s about crapshoots that might work and would pay off in some way - often any financially feasible way.
They once put “cats” on guns in hopes it would surprise opponents even just for a quarter second, giving your spec ops dudes the advantage. They tried to create angled guns that could shoot around corners like 20 years ago. All kinds of crazy stuff! It would be a lot of fun to work there, I think.
The germans tried the curved gun with an attachment called Krummlauf during ww2. It would break after just a couple of magazines being fired. https://en.wikipedia.org/wiki/Krummlauf
Not sure how you would build one of those without the stress of the bullet during firing would not damage the barrel.
I'm amazed that worked for even one shot. Presumably gp was referring to cornershot or something similar, which seems like a much more reasonable approach.
“It’s a lot easier to send a power beam directly up or down relative to the ground because there is so much less atmosphere to fight through,” Jaffe explains. “For PRAD, we wanted to test under the maximum impact of atmospheric effects.”
Super impressive! My only complain is that this was done at the White Sounds desert in New Mexico, at over 1200 meters of elevation. For maximum impact they should have done it in Florida on a hot humid day
There’s no range in Florida large enough for this test otherwise I’m sure they would have.
Even Eglin wouldn’t be large enough.
Humidity would most likely attenuate the beam from 20% end to end to less than 1% - water vapour absorbs energy like nobody’s business.
This is a tech for arid environments - which seem to be where the US does most of its deployments these days.
The application to drones seems most clear: beam drones some extra power as needed. Or continually!
I wonder how big that receiving apparatus is. Whether the receiver is gimballed, or whether the drone itself has to fly a heading to aim at the sender: TBD.
And have a great opportunity to drill some holes in birds heads.
Sorry I really fail to recognise how beaming 1kw of excited particles is a safe thing to do just like this…
It must not be safe to be out in the sun then.
Last time I forgot sunscreen at a UV index of 10 my skin started peeling of after half an hour so...
[flagged]
How about drones with a solar panel case? Would require a sunny day to work at all though.
Tiny nuclear reactor?
How about drones with a solar panel case? Would require a sunny day to work at all though.
Tiny nuclear reactor?
"reflects onto dozens of photovoltaic cells arranged around the inside of the device which convert the energy back to usable power."
This is no different that what we were considering two decades ago for the space elevator competition. One of the problems with this approach is that as the photovoltaic cells heat up their overall efficiency decreases.
They'll only get so hot, and you can just spread the energy across more cells, right?
Could this also be a viable alternative to HVDC lines for civilian applications?
No. 800 watts (vs megawatts for HVDC). 5 miles vs thousands of miles. 20% efficiency optical to electrical - so electrical vs electrical is much worse - vs 90%+.
This is so much worse in every aspect it's not really compareable.
It's great if you hate birds, though.
The key thing they aren't saying is how much power it took to "send" 800 watts 5.3 miles...
They mentioned that it was 20% efficient at a closer distance.
So likely much lower than that.
Wow that's a long way from the proposals for sending GW of microwave power from satellites.
But pretty close to powering drones from ground stations
Laser power beaming from space could be useful at lower power levels than that, for example for powering aircraft.
This seems very silly. It's either a death ray project in a fake mustache or somebody had earmarked a bunch of money that they had to spend before it expired.
This is kinda surprising to read. I’ve never known anyone who isn’t incredibly excited at least at the prospect of wireless energy transfers. If you can do 800 watts over 8 km, surely we can do 150 watts across 3 feet in the household, and MANY of our most important discoveries come from DARPA essentially being a black budget skunkworks team.
But much of the stuff DARPA does seems weird. It’s not about ideas with solid foundation and thorough engineering, it’s about crapshoots that might work and would pay off in some way - often any financially feasible way.
They once put “cats” on guns in hopes it would surprise opponents even just for a quarter second, giving your spec ops dudes the advantage. They tried to create angled guns that could shoot around corners like 20 years ago. All kinds of crazy stuff! It would be a lot of fun to work there, I think.
The germans tried the curved gun with an attachment called Krummlauf during ww2. It would break after just a couple of magazines being fired. https://en.wikipedia.org/wiki/Krummlauf
Not sure how you would build one of those without the stress of the bullet during firing would not damage the barrel.
I'm amazed that worked for even one shot. Presumably gp was referring to cornershot or something similar, which seems like a much more reasonable approach.