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Powering cargo planes seems like a niche market that would be suitable. The planes could have just enough power to get up above the cloud layer, then receive a

Powering cargo planes seems like a niche market that would be suitable. The planes could have just enough power to get up above the cloud layer, then receive a charge boost each time they go below each solar powered satellite. This makes the planes lighter as they no longer need to carry as much fuel or batteries. A second consideration is that these satellites can be factories in space. Raw materials are much easier to launch into space using rail guns as the materials can survive higher g forces then humans or pre-manufactured goods. Once in space, the raw materials can be made into higher quality goods due to the lack of atmosphere and gravity. Once they are in space they can be put to use making further satellites, orbital rings or habitats.

bastawhiz 4y ago
Call me old fashioned, but the thought of putting a massive, heavy tube into the air full of cargo without enough energy to get it to its destination seems like an idea that will get a lot of people killed. I can't even get reliable satellite TV, I don't want "keep a plane of Amazon packages from landing in my attic" reception to be a thing I need to think about.
- krasin 4y ago
  The primary use case here is trans-pacific. Not a lot of attics out there.
  - akira2501 4y ago
    "Yea.. if it crashes, it just crashes into the ocean. What would the problem with that be?" Move fast and break things as applied to air transport really makes for some exciting opportunities, doesn't it?
    - krasin 4y ago
      We can either be infinitely scared and do nothing or we can actually make progress in a responsible manner and get a chance to fix climate.
      - akira2501 4y ago
        This is not a responsible solution, and believing so doesn't belie some "infinite fright," nor does it discount the thousands of more reasonable solutions that could be applied here first. If you honestly thought "space based power beams" were a realistic solution, then why you would even propose a plane as opposed to a boat is entirely beyond me. This idea that we're just going to find some "plug in" solution to our current infrastructure that's suddenly net positive for the climate only invites these kinds of irresponsible flights of fancy. If you want an honest solution, then you're going to have to reconsider the mechanisms that cause you to fly cargo across the globe on jets in the first place. These systems were built for profit, and they continue to operate with profit as their primary motivation. If you want to manage the climate "responsibly" then you need to put it first, and when you do so, you realize that our current means of distributing products around the world is patently insane. Only by ignoring that problem or hoping that literal "power beams from outer space" will magically become available and prevent any restructuring of profit flows leads to this kind of nonsense thinking.
      - bastawhiz 4y ago
        The answer is not to do nothing. The answer is to reject bad ideas that would turn cruise ships into potential floating craters and instead pursue ideas that are both tractable and won't treat people as collateral damage.
        krasin 4y ago
        > bad ideas that would turn cruise ships into potential floating craters Is the concern here is a sudden loss of power or autonomous flight? If a beam is lost, these electric cargo planes will have enough batteries for 20-30 minutes of flight until power is restored. In the worst case, they would have to make a safe emergency landing in the ocean without hitting ships. If the concern is about autonomous flight, then it's not really different from many other autonomous systems: they absolutely work, but have to be implemented responsibly and pass regulatory audit.
        ben_w 4y ago
- bergenty 4y ago
  Unmanned cargo planes with fail safes over ocean routes doesn’t seem too dangerous.
  - bastawhiz 4y ago
    There's no such thing as a fail safe for a plane running out of gas.
    - bergenty 4y ago
      Sure there is, prepare to safely crash with 5% left
- nanomonkey 4y ago
  It's not too hard to engineer a system that could handle missing a beamed refuel. One could achieve a lot of benefits from a hybrid turbine that uses fuel for take-off and "emergency events", and powered electric from satellites. I'd assume that there would be a whole constellation of satellites, so if one is missed the next would be within range, or the plane could land safely with a backup liquid fuel supply. Ideally the plane would have a high glide slope ratio. Satellites with beam forming technologies could also map out thermals and plot out ideal courses. This is all a thought experiment on achievable engineering. Have fun with it.
  - bastawhiz 4y ago
    Or, we could just say that two day shipping for all goods wasn't ever a sustainable idea and use—and hear me out on this—boats. Boats don't sink when they run out of fuel, and can be reliably run on electricity. Heaven forbid we sacrifice the convenience of Amazon's Buy Now button in the interest of the planet not frying to a crisp.
- HWR_14 4y ago
  Yeah, that's old fashioned. A fully loaded 747 flying at cruising altitude will be able to go between 108 and 144 miles before landing if all the engines suddenly died (the difference is because of the fairly large range of heights that constitute "cruising altitude"). More modern planes can go even further from the same height. Planes designed to optimize that number can reach 360-480 miles if the engines fail (but obviously those planes carry less cargo).
Someone 4y ago
> Powering cargo planes seems like a niche market that would be suitable FTA: Most designs aim to produce a beam kilometers wide so that any spacecraft, plane, person, or bird that strays into it only receives a tiny—hopefully harmless—portion of the 2-gigawatt transmission 2 GW on a _single_ km² is 2kW per m², about twice what solar power provides. “Kilometers wide” could easily mean 10km², or 200W/m². ⇒ it will be difficult to get the power density to power an airplane, even if it’s only for flying at height.
- robbiep 4y ago
  I think your maths is off - there are 1m square metres in 1 sq kilometre, but 2000 kW in a GW, meaning approx 0.002 kW per square meter. Which kind of makes this whole thing a weird economic proposition. You’re beaming energy from space at a density that approximates solar insolation, and still have to build the collector and convert it back - wouldn’t it be easier to just collect the solar insolation?
  - IanCal 4y ago
    > I think your maths is off - there are 1m square metres in 1 sq kilometre, but 2000 kW in a GW, meaning approx 0.002 kW per square meter. That's not right. There's 2000 kW in a MW, not GW. 2GW is 2e9W, so over 1e6,^2 that's 2e3W/m^2 or 2kW/m^2.
    - robbiep 4y ago
      Ahh thankyou for sorting me out. My apologies OP
  - pencilguin 4y ago
    There are, in fact only 1000 kW in a MW, or 1,000,000 kW in a GW. Where is this factor of 2 coming from?
- Schroedingersat 4y ago
  There are already planes that can fly (and do nothing else useful) on 300W/m^2 Solar panels already have sufficient mass power density. There's a pretty big gap between the 10s of MW a jumbo needs and the 700m^2 of area it has. If you were willing to trade some flight speed you could increase wing area 5x or so, and maybe make it work in the 2-4kW/m^2 range if all of the photons were at your bandgap.

bastawhiz 4y ago

Call me old fashioned, but the thought of putting a massive, heavy tube into the air full of cargo without enough energy to get it to its destination seems like an idea that will get a lot of people killed. I can't even get reliable satellite TV, I don't want "keep a plane of Amazon packages from landing in my attic" reception to be a thing I need to think about.

krasin 4y ago
The primary use case here is trans-pacific. Not a lot of attics out there.
- akira2501 4y ago
  "Yea.. if it crashes, it just crashes into the ocean. What would the problem with that be?" Move fast and break things as applied to air transport really makes for some exciting opportunities, doesn't it?
  - krasin 4y ago
    We can either be infinitely scared and do nothing or we can actually make progress in a responsible manner and get a chance to fix climate.
    - akira2501 4y ago
      This is not a responsible solution, and believing so doesn't belie some "infinite fright," nor does it discount the thousands of more reasonable solutions that could be applied here first. If you honestly thought "space based power beams" were a realistic solution, then why you would even propose a plane as opposed to a boat is entirely beyond me. This idea that we're just going to find some "plug in" solution to our current infrastructure that's suddenly net positive for the climate only invites these kinds of irresponsible flights of fancy. If you want an honest solution, then you're going to have to reconsider the mechanisms that cause you to fly cargo across the globe on jets in the first place. These systems were built for profit, and they continue to operate with profit as their primary motivation. If you want to manage the climate "responsibly" then you need to put it first, and when you do so, you realize that our current means of distributing products around the world is patently insane. Only by ignoring that problem or hoping that literal "power beams from outer space" will magically become available and prevent any restructuring of profit flows leads to this kind of nonsense thinking.
    - bastawhiz 4y ago
      The answer is not to do nothing. The answer is to reject bad ideas that would turn cruise ships into potential floating craters and instead pursue ideas that are both tractable and won't treat people as collateral damage.
      - krasin 4y ago
        > bad ideas that would turn cruise ships into potential floating craters Is the concern here is a sudden loss of power or autonomous flight? If a beam is lost, these electric cargo planes will have enough batteries for 20-30 minutes of flight until power is restored. In the worst case, they would have to make a safe emergency landing in the ocean without hitting ships. If the concern is about autonomous flight, then it's not really different from many other autonomous systems: they absolutely work, but have to be implemented responsibly and pass regulatory audit.
        ben_w 4y ago
bergenty 4y ago
Unmanned cargo planes with fail safes over ocean routes doesn’t seem too dangerous.
- bastawhiz 4y ago
  There's no such thing as a fail safe for a plane running out of gas.
  - bergenty 4y ago
    Sure there is, prepare to safely crash with 5% left
nanomonkey 4y ago
It's not too hard to engineer a system that could handle missing a beamed refuel. One could achieve a lot of benefits from a hybrid turbine that uses fuel for take-off and "emergency events", and powered electric from satellites. I'd assume that there would be a whole constellation of satellites, so if one is missed the next would be within range, or the plane could land safely with a backup liquid fuel supply. Ideally the plane would have a high glide slope ratio. Satellites with beam forming technologies could also map out thermals and plot out ideal courses. This is all a thought experiment on achievable engineering. Have fun with it.
- bastawhiz 4y ago
  Or, we could just say that two day shipping for all goods wasn't ever a sustainable idea and use—and hear me out on this—boats. Boats don't sink when they run out of fuel, and can be reliably run on electricity. Heaven forbid we sacrifice the convenience of Amazon's Buy Now button in the interest of the planet not frying to a crisp.
HWR_14 4y ago
Yeah, that's old fashioned. A fully loaded 747 flying at cruising altitude will be able to go between 108 and 144 miles before landing if all the engines suddenly died (the difference is because of the fairly large range of heights that constitute "cruising altitude"). More modern planes can go even further from the same height. Planes designed to optimize that number can reach 360-480 miles if the engines fail (but obviously those planes carry less cargo).

Someone 4y ago

> Powering cargo planes seems like a niche market that would be suitable FTA: Most designs aim to produce a beam kilometers wide so that any spacecraft, plane, person, or bird that strays into it only receives a tiny—hopefully harmless—portion of the 2-gigawatt transmission 2 GW on a _single_ km² is 2kW per m², about twice what solar power provides. “Kilometers wide” could easily mean 10km², or 200W/m². ⇒ it will be difficult to get the power density to power an airplane, even if it’s only for flying at height.

robbiep 4y ago
I think your maths is off - there are 1m square metres in 1 sq kilometre, but 2000 kW in a GW, meaning approx 0.002 kW per square meter. Which kind of makes this whole thing a weird economic proposition. You’re beaming energy from space at a density that approximates solar insolation, and still have to build the collector and convert it back - wouldn’t it be easier to just collect the solar insolation?
- IanCal 4y ago
  > I think your maths is off - there are 1m square metres in 1 sq kilometre, but 2000 kW in a GW, meaning approx 0.002 kW per square meter. That's not right. There's 2000 kW in a MW, not GW. 2GW is 2e9W, so over 1e6,^2 that's 2e3W/m^2 or 2kW/m^2.
  - robbiep 4y ago
    Ahh thankyou for sorting me out. My apologies OP
- pencilguin 4y ago
  There are, in fact only 1000 kW in a MW, or 1,000,000 kW in a GW. Where is this factor of 2 coming from?
Schroedingersat 4y ago
There are already planes that can fly (and do nothing else useful) on 300W/m^2 Solar panels already have sufficient mass power density. There's a pretty big gap between the 10s of MW a jumbo needs and the 700m^2 of area it has. If you were willing to trade some flight speed you could increase wing area 5x or so, and maybe make it work in the 2-4kW/m^2 range if all of the photons were at your bandgap.