[HN Gopher] Solar-powered aircraft flown for nearly three weeks ...
___________________________________________________________________
Solar-powered aircraft flown for nearly three weeks without landing
Author : OJFord
Score : 233 points
Date : 2021-10-11 15:49 UTC (7 hours ago)
(HTM) web link (eandt.theiet.org)
(TXT) w3m dump (eandt.theiet.org)
| hellohntoday wrote:
| I'm assuming the flights were achieved mid summer when they days
| are longest and it can't yet operate outside this window.
|
| If this is the case, shame they don't just admit this up front
| phnofive wrote:
| Perhaps they are aware of eatrh's axis and will move operations
| to the southern hemisphere? Or adjust the drone's speed to stay
| in sunlight?
| Arrath wrote:
| > Or adjust the drone's speed to stay in sunlight?
|
| Depending on altitude, that would require an awfully fast
| aircraft.
| Johnny555 wrote:
| They ran the 18 day flight test in September, so not the dead
| of winter, but also not on the longest summer days:
|
| _A solar-powered aircraft has completed an 18-day test flight
| offering hope it could be used to create internet access for
| billions of unconnected people around the world...The test
| flight touched down in Arizona on September 13._
|
| https://www.thenationalnews.com/world/the-americas/2021/10/1...
|
| Phoenix has about 12.5 hours of daylight on Sept 13th.
| (compared to ~14.5 hours on June 21st, ~10 hours on Dec 21st.
| GhostVII wrote:
| What's the benefit over something like a weather balloon?
|
| Pretty interesting thought, tape a few hundred micro SD cards to
| it and you've got some impressive bandwidth.
| brandmeyer wrote:
| Google's Titan project was going to deliver internet service
| (... _before it got strangled in the womb grumble grumble_
| ...). LTE from aircraft to client, and a dedicated point-to-
| point radio from aircraft to backbone.
| detritus wrote:
| You can tell this where to go - weather balloons are utterly
| beholden to the whim of wind patterns.
| runarberg wrote:
| I thought that you could somewhat control a balloon by using
| different wind patterns in different elevations.
|
| https://www.youtube.com/watch?v=NvJ2Ei8K2DI
| bentcorner wrote:
| ?Por que no los dos?
|
| It looks like solar-powered zeppelins are a thing, although
| with the brief googling I did it looks like nothing really
| exists just yet.
| GhostVII wrote:
| Yea I guess I was more thinking of a kind of blimp, where it
| still has some solar to allow it to maneuver around, but not
| to actually stay up.
|
| If the aircraft needs to stay in one place maybe that would
| be less efficient though, since it would be harder to fight
| winds.
| jcun4128 wrote:
| The wing tips look wicked, not sure if necessary
| laurent92 wrote:
| Isn't taxi-takeoff-landing what consumes the most energy? It's
| often 10% to 25% of the total flight consumption for supersonic
| planes like the Concorde (but not for the SR-71, since they
| refueled in-flight to fill the rest with inert gas
| https://theaviationgeekclub.com/former-sr-71-driver-explains...
| ), and still a lot for the other planes.
| OJFord wrote:
| Based on your percentages then, I think you mean most per unit
| time? So then, given three weeks far exceeds normal flight time
| (by more than 1/25%)...
| elif wrote:
| I like the optimism of the article but I can't help but believe
| that the primary purchasers of this capability will be armies and
| spies.
| fredliu wrote:
| Wasn't Facebook working on a similar project (Aquila)?
| wanderingstan wrote:
| Yes, it was cancelled in 2018:
| https://techcrunch.com/2018/06/26/facebook-permanently-groun...
| akozak wrote:
| Doesn't appear to have a payload in the picture. That would add
| weight & power draw.
| nabla9 wrote:
| First communications satellites were just passive reflectors.
| They were just big inflated balloons made with reflective
| material.
|
| Same idea could work with solar powered aircraft.
|
| https://en.wikipedia.org/wiki/PAGEOS
|
| https://en.wikipedia.org/wiki/Project_Echo
| not-my-account wrote:
| "Airbus ultimately believes that the aircraft could remain
| airborne for "months at a time" and could provide internet to
| both commercial and military customers."
|
| What sort of power requirements would this bring? I assume that
| it would be more sophisticated than just dumping RF energy
| indiscriminately across a huge area.
| zarazas wrote:
| But there is starlink for internet in rural areas
| onychomys wrote:
| Sure, but even if these planes managed to somehow cost as much
| as a starlink satellite, it'd still be cheaper to do it this
| way because having some dude toss it up into the air for
| takeoff is basically free compared to even a fully reusable
| Starship flight.
| kbenson wrote:
| They're hoping to get six months flight eventually out of a
| propeller craft. I can't help but wonder what we could eventually
| get out of a solid state craft.[1] They mention batteries in this
| article when referencing that six months target, but I have to
| assume servicing the propellers is important as well.
|
| 1: https://www.engineering.com/story/how-the-worlds-first-
| solid...
| Asmod4n wrote:
| You got a small typo there.
| kbenson wrote:
| Lol, thanks. :)
| bagels wrote:
| To fly through the night, you need energy. I'm wondering if it's
| more efficient to store it in the batteries, or as stored kinetic
| energy by flying to a high altitude and descending through the
| night.
| teraflop wrote:
| It's a good idea, in principle. But according to the sources I
| could find, to get enough gravitational potential energy to
| equal the electrical capacity of Zephyr's batteries, you'd have
| to lift the entire craft by about 70km.
|
| https://www.aviationpros.com/engines-components/aircraft-air...
|
| https://en.wikipedia.org/wiki/Airbus_Zephyr
|
| I can imagine you'd want to take advantage of gravity to a
| certain extent, but it seems a bit tricky to estimate how much.
| Presumably there's a particular altitude at which the
| aircraft's overall efficiency is at a maximum. Deviating from
| this altitude allows you to store a bit of extra energy (which
| means you can get away with a smaller battery) but you don't
| want to deviate too far, or you'll lose more energy to various
| inefficiencies than you're saving. And you probably need to
| keep some electrical reserve power anyway, in order to be able
| to actively navigate away from unfavorable winds.
| kbenson wrote:
| There's also the fact that this is optimizing for power usage
| in the air, when really what we'll want to optimize for most
| likely is power usage while _doing some specific task_ in the
| air, and that task may necessitate specifics of what
| altitudes it can function at.
| Ph0X wrote:
| Assuming you didn't care about the path, could you also take
| some optimal path where you go east to west to prolong the
| days, then go west to east to shorten the nights. Could
| probably play with south/north too depending on the time of the
| year to get longer days. Or maybe you can go far enough to the
| pole where it's always day.
| gusgordon wrote:
| For those curious about the physics of these aircraft, here's an
| analysis I did of the same concept. The goal is to determine the
| smallest aircraft configuration that can indefinitely sustain
| flight: https://github.com/gusgordon/atmospheric_satellite#readme
| onychomys wrote:
| Is there a reason you optimized the amount of starting energy
| in the battery? I know basically nothing about how solar power
| works, but surely you'd just fill the battery up to 100% with
| an extension cord on the ground before launching it?
| mkr-hn wrote:
| Batteries are heavier when fully charged. Takeoff weight
| matters. It's not much heavier, but it might be enough to
| affect things at this scale.
|
| edit: remember the context. This is about an abstract
| optimization to find the minimum viable aircraft.
| rrss wrote:
| what kind of batteries are meaningfully heavier when
| charged? are you just talking about like E/c^2?
| luma wrote:
| Gas tanks :D
| jermaustin1 wrote:
| A water/gravity battery comes to mind. Definitely not the
| answer you are looking for, but an answer none the less.
| enchiridion wrote:
| Depends on your definitions. Is the water pumped
| considered part of the battery before it's elevated?
| jermaustin1 wrote:
| The pumping of the water would be "charging" the barrel
| of water, I guess.
| einpoklum wrote:
| I'm sure this will work great for powering an aircraft,
| too. You could just let it all hang from an anchor at the
| highest point in the battery :-P
| spijdar wrote:
| I can't tell if this is satire or not, but taken in good
| faith, how?
|
| A fully charged battery would necessarily have more mass
| than a fully depleted battery, but the difference should be
| so tiny as to be immeasurable. Or am I wrong? We're
| essentially talking about the sum weight of a bunch of
| electrons, which are extremely light. There's no other
| exchange of matter going on when charging/discharging a
| battery, just the creation/destruction of chemical bonds,
| and associated movement of electrons.
| btilly wrote:
| A battery doesn't have a static charge. When it
| discharges, electrons move from one side to the other,
| then back through the batter, and you modify which atoms
| have which elections. But it continues to have no static
| charge.
|
| However it has less potential energy. And therefore you
| change mass by the mass associated with that potential
| energy.
| [deleted]
| luma wrote:
| I can't tell if you're being serious. You are _technically_
| correct, but also incredibly wrong in suggesting that the
| increased weight would be substantial enough to impact
| anything measurable. Depending on the size and capacity of
| the cell, you might see a difference due to general
| relativity on the order of nanograms.
|
| see:
| https://physics.stackexchange.com/questions/34421/does-
| the-m...
| p1mrx wrote:
| A nanogram saved is a nanogram earned.
| gusgordon wrote:
| Good question. One requirement for the aircraft in this
| optimization is that they must have more energy in the
| battery than they did 24 hours prior. If the aircraft started
| at full energy, they wouldn't ever be able to satisfy this
| requirement, so that's why it's an independent variable.
|
| For example, an aircraft could "start" at 50% battery state
| of charge, then charge to 95% over the course of the day,
| then come back 24 hours later at 51%, and that would be
| valid. There are other ways around this, but this is what I
| came up with at the time.
|
| This is similar to why the starting altitude is allowed to
| float. The gravitational potential energy of the aircraft can
| be used as another "battery", but the aircraft is only a
| valid solution if it's not losing altitude over the course of
| 24 hours.
| jcims wrote:
| Maybe it helps surface how much charge is required to climb
| to altitude vs how much charge is required to sustain it?
| This may also help surface how much of a buffer you may have
| in takeoff time in order to survive night. E.g. if you
| require 100% charge then it's likely you have to take off at
| a fairly specific time of day.
| algo_trader wrote:
| nice analysis
|
| Is it feasible to operate these at lower altitudes?
|
| e.g. can we have solar/air drones posted every 100 miles of
| interstate highway?!
| gusgordon wrote:
| Yes it's a lot easier at lower altitudes since you can get
| more lift, but you might run into some extra regulatory
| issues with that :)
| giantg2 wrote:
| I would love a low cost electric ultralight.
| jack_riminton wrote:
| " It is a sustainable, solar-powered, ISR and network-extending
| solution that can provide vital future connectivity and earth
| observation to where it is needed"
|
| This military-industrial style of English always sounds very odd
| and is ubiquitous with these companies. Is it because they're
| selling to Military buyers?
| marcodiego wrote:
| Complete outsider doubt: Does this has the potential to replace
| satellites? Or, why did google project loon failed?
| elif wrote:
| A craft like this is more likely to serve
| predator/reaper/sentinel missions. Particularly ones in
| locations you don't want the aesthetics of full state
| surveilance but still want the same operational capacity.
| Tade0 wrote:
| Not mentioned in the article, but the li-ion batteries onboard
| the aircraft have a silicon nanowire anode thus achieving amazing
| energy density:
|
| https://www.amprius.com/2019/10/airbus-partners-with-amprius...
| stavros wrote:
| Do you know what sort of density and discharge rates they're
| talking?
| tehjoker wrote:
| I wonder how the engine can keep operating for such long periods
| of time without maintenance!
| endymi0n wrote:
| This stuff is pretty sturdy. The lifetime of brushless electric
| motors used in this kind of dirtless environment is basically
| the lifetime of the bearing used and can usually be measured in
| years of nonstop operation without any modification already.
| JCM9 wrote:
| In 1958 two guys flew a Cessna 172 nonstop for 64 days without
| landing. They refueled mid-air via a truck that drove under them
| during a low pass.
| hodgesrm wrote:
| Good Lord, what an adventure! Thank you for posting!! I had no
| idea about this flight.
|
| Here's an account that popped up on Google.
|
| https://www.aopa.org/news-and-media/all-news/2008/march/01/e...
| markl42 wrote:
| how did they um...."defuel" their bodies and such in the air?
| philk10 wrote:
| https://news.ycombinator.com/item?id=18158207
| spookthesunset wrote:
| Summary: they pooped into plastic bags and tossed them
| overboard.
| orzig wrote:
| Even more impressive, they did it before audiobooks!
| njovin wrote:
| I had never heard of this record until now. Cross-country
| flying in small planes like this can be incredibly tedious and
| the refueling sounds very dangerous. I can't imagine doing it
| for this long. Apparently, neither can the guy who did it:
|
| > When asked by a reporter if he would ever replicate the
| stunt, Cook replied: "Next time I feel in the mood to fly
| endurance, I'm going to lock myself in a garbage can with the
| vacuum cleaner running, and have Bob serve me T-bone steaks
| chopped up in a thermos bottle. That is, until my psychiatrist
| opens for business in the morning."
|
| Source: https://www.airspacemag.com/daily-planet/airborne-
| for-64-day...
| sokoloff wrote:
| Related (in at least one dimension):
| https://www.airspacemag.com/daily-planet/airborne-for-64-day...
|
| Cessna 172 flown for 64 days, 22 hours, 19 minutes and 5 seconds.
| etaioinshrdlu wrote:
| The linked article on that page is broken. I'm guessing he
| somehow refueled in flight?
| sokoloff wrote:
| Yes. Also added oil.
| ceejayoz wrote:
| Yes. They flew low and slow over a long, straight road and
| refueled from a truck that kept pace with them.
|
| https://www.aopa.org/news-and-media/all-
| news/2008/march/pilo...
|
| > A Ford truck, donated by Cashman Auto in Las Vegas, was
| outfitted with a fuel pump, tank, and other paraphernalia
| required to support the aircraft in flight. When fuel was
| required, a rendezvous would be arranged on a stretch of
| straight road in the desert near Blythe, California. An
| electric winch lowered a hook, the fuel pump hose was picked
| up, and Timm or Cook inserted it into the belly tank. It took
| a little more than three minutes to fill the belly tank.
|
| > The total fuel capacity of the airplane was 142 gallons.
| Plans called for refueling twice daily. Sometimes weather or
| the inevitable glitches upset the schedule, and a new
| rendezvous was worked out by radio. This activity was
| repeated more than 128 times.
|
| The whole article is worth a read; it was quite the hairy
| sounding endeavour. Two months in a C-172 would kill me, I'm
| quite certain.
| belthesar wrote:
| https://web.archive.org/web/20120429214314/http://www.airspa.
| ..
|
| Haven't read it to find the answer to your question yet, but
| bless the Internet Archive
| sologoub wrote:
| > When asked by a reporter if he would ever replicate the
| stunt, Cook replied: "Next time I feel in the mood to fly
| endurance, I'm going to lock myself in a garbage can with the
| vacuum cleaner running, and have Bob serve me T-bone steaks
| chopped up in a thermos bottle. That is, until my psychiatrist
| opens for business in the morning."
|
| ROLF!!!
| mr337 wrote:
| I think he sums this up nicely. What a feat!
| mistrial9 wrote:
| https://en.wikipedia.org/wiki/Cessna_172 :
|
| "From December 4, 1958, to February 7, 1959, Robert Timm and
| John Cook set the world record for (refueled) flight endurance
| in a used Cessna 172, registration number N9172B. They took off
| from McCarran Airfield in Las Vegas, Nevada, and landed back at
| McCarran Airfield after 64 days, 22 hours, 19 minutes and 5
| seconds in flight. The flight was part of a fund-raising effort
| for the Damon Runyon Cancer Fund.[14][15]"
| j245 wrote:
| Neat - but not interesting from a technological stand point.
| andrepew wrote:
| Over 1500 hours of continuous operation is quite a feat.
| Components like magnetos have service schedules much shorter
| than that.
|
| This also ignores all the unexpected issues that pop up in
| aviation. My only experience with Cessna 172s are rentals
| which are treated like crap - those planes need something
| looked at like every 50 hours.
| OJFord wrote:
| Is it not? I don't imagine such sustained flight, continuous
| operation of all the equipment and engine for so long,
| would've been a design consideration.
|
| Presumably there's a number, I just doubt it's tens of days,
| so isn't it _interesting_ that it was achieved?
| j245 wrote:
| This record was set ~3 months after someone else did it for
| 50 days.
|
| From an engineering stand point, performance of components
| or materials are always assumed to be much worse than
| actual and the forces / conditions they are subject to
| overestimated, with further factors of safety applied on
| top. This is how it should be. It also means properly
| designed things will carry on working better than you
| expect (on average).
|
| It's not interesting (to me) from a technological stand
| point compared to the solar UAV because flying up and down
| the same road with a truck refuelling you is not useful,
| and if others (e.g. Military, NASA) could be bothered to do
| it - they would probably do a better job relatively easily.
|
| To me - It's the same as building the worlds longest domino
| trail. You could beat the previous record by 1 million
| dominos which is neat but.. what have you proven, and why
| does it matter ?
| OJFord wrote:
| > This record was set ~3 months after someone else did it
| for 50 days.
|
| Fair enough, I didn't know about that, I'd have been _as_
| interested to hear about either of them first, and like
| you not so much the other second. (And I doubt the
| commenter that shared it meant it as 'wow look 64
| compared to 50' either.)
| cornellwright wrote:
| You can see the aircraft used at the Las Vegas airport. It says
| "Hacienda Hotel" on the side and I think it's hanging over
| baggage claim.
| tpmx wrote:
| Probably/unfortunately not really a Starlink competitor, right?
|
| They don't specify the "cruising" altitude, but I assume it's ~10
| kilometers at most, probably less?
|
| Airbus would need quite a few of these in order to build a global
| internet connectivity service then.
|
| Edit: https://en.wikipedia.org/wiki/Airbus_Zephyr says ~20 km.
|
| Starlink sats (will) operate at ~540-570 km:
|
| https://spaceflightnow.com/2021/04/29/spacex-launches-60-mor...
| rlt wrote:
| They would have the advantage of variable density based on
| demand, i.e. more of them over population centers and none over
| oceans, whereas LEO satellite constellations are pretty
| uniformly distributed because they're orbiting.
|
| It's sort of in between a stationary cell tower and LEO
| satellite constellation.
|
| But then you have to worry about them failing and hitting those
| population centers, whereas satellites deorbit slowly and
| usually burn up completely.
| Ottolay wrote:
| The U2 operated at over 20km, so maybe the altitude is higher.
|
| I suspect the greater issue is vehicle cost, lifetime, and
| safety. A starlink satellite is much smaller (and as result
| cheaper) and is rumored to have a 5+ year lifetime. Also, at
| end of life it burns up in the atmosphere. No worry about
| pushing the life on a component and having it crash and kill
| someone as a result.
| elif wrote:
| Glide based efficiency crafts absolutely need thick
| atmosphere. They don't have supersonic jets.
| Ottolay wrote:
| The U2 was subsonic. Also, un-powered gliders can get up to
| impressive altitudes.
|
| https://www.airbus.com/newsroom/press-
| releases/en/2018/09/ai...
| JackFr wrote:
| > The unmanned glider, which is powered by two small
| propellers,
|
| I'm confused by the article and the above comment. Isn't
| a glider by definition unpowered?
| runarberg wrote:
| I'm a bit puzzled by the economy here. Is creating, lunching
| and orbiting a satellite really cheaper then flying an
| airplane? Is it really cheaper to have a decommissioned
| satellite totally burn up in the atmosphere then reusing
| parts of an airplane to fix another, recycle unusable parts
| and put the rest in a landfill?
|
| The economics here just seem wrong.
| ethbr0 wrote:
| USD2021$15M per Falcon 9 launch (re-used, assuming first
| launch was paid for by a customer) [0]
|
| 60 Starlink satellites per Falcon 9 launch [1]
|
| = + USD2021$250,000 in launch costs per satellite (+
| manufacturing / ops costs)
|
| [0] https://www.elonx.net/how-much-does-it-cost-to-launch-
| a-reus...
|
| [1] https://space4peace.org/starlink-gears-up-to-launch-
| nearly-1...
| Ottolay wrote:
| As a reference a new Cessna 172 is $432,000 [1] and that
| is not a high tech aircraft.
|
| [1] https://www.forbes.com/sites/erictegler/2021/04/28/pr
| ices-fo...
| runarberg wrote:
| This feels like comparing potatoes and pineapples.
|
| A _new_ Cessna vs a _used_ Falcon 9 _launch_ hardly seems
| like a fair comparison. The cost of the rocket is written
| off as externalized. The actual satellites are not
| factored in at all. Really what we are comparing here is
| the cost of an operation vs the cost of an airplane. The
| economics still seem dubious.
| rlt wrote:
| On top of this, if Starship is successful ("fully and
| rapidly reusable") it could bring the launch cost down
| another order of magnitude.
|
| And because Starlink is building thousands of satellites
| it has economies of scale that no previous
| satellite/spacecraft had.
| tomxor wrote:
| [EDIT] remove redundant info
|
| > Airbus would need quite a few of these in order to build a
| global internet connectivity service then.
|
| Yes it would require more units, but with a much smaller cost
| per unit for build, launch and maintenance. That's where it
| will start to get interesting: Which will have the lowest cost
| per GB, per user, per square km of coverage etc?
|
| I suspect even if it's cheaper it would still remain less
| global, since having massive swarms of these would probably be
| even more of a logistical nightmare than starlink. i.e they
| would supplement other technology... which is pretty much what
| Airbus is quoted suggesting in the article.
| Gravityloss wrote:
| You wouldn't need that many. The line of sight area has 300 km
| radius. There's even a precedent.
| https://en.wikipedia.org/wiki/Stratovision
| Tepix wrote:
| These planes can compete with Starlink in certain scenarios,
| for example you can launch them in the event of floods that
| knock out the regular telecommunications infrastructure.
| tpmx wrote:
| With Starlink soon having ~global coverage, why bother
| transporting, launching and servicing these aircraft for a
| one time thing? I don't see the benefit. Will also be really
| hard to reach low prices for end user terminals with this
| approach.
|
| Very high quality visual/signals surveillance seems like a
| much more obvious market fit.
| btilly wrote:
| First, Starlink has limited bandwidth per square mile.
| Therefore it cannot conceivably provide telecommunications
| for densely populated areas.
|
| Second, all you have to do is make these aircraft
| compatible with cell phones. So your target population
| already has "end user terminals" literally in hand.
|
| Third, this is not a one-time need. Local disasters happen
| fairly regularly, and sometimes can be predicted in
| advance. (For example hurricanes.) There is real value to
| an instant telecommunications network that can be deployed
| on short notice.
|
| Now I don't claim that this is actually economically
| viable. But it is not exactly crazy, either.
| tpmx wrote:
| Pretty good points. Starlink can't do 2G/3G/4G/5G with
| mobile phones on the ground, ~550+ km away, of course.
|
| They should probably look into partnering with e.g.
| Ericsson Response (https://www.ericsson.com/en/about-
| us/sustainability-and-corp...).
| kbenson wrote:
| > Very high quality visual/signals surveillance seems like
| a much more obvious market fit.
|
| Oh, yeah, there are already companies the provide complete
| surveillance of cities or large areas of cities so that
| even if a crime scene is discovered hours or days later,
| they can just go back to that time and track vehicle
| movement to and from the crime scene to wherever it ends up
| as long as it's in the same (large) area.
|
| Reducing the cost of the equipment that does the recording
| of the area will only make it more accessible to more
| police departments, for better or worse.
| stareatgoats wrote:
| This is great and points to how solar in some cases already can
| facilitate continuous operation without the need for refueling of
| planes, boats, cars, you name it. Expect this to grow as battery
| and solar cell tech develops further.
|
| My favorites atm are the yachts that are capable of sailing just
| about anywhere in the world without a drop of fuel. The price is
| prohibitive, but considering that you might not need a house
| anymore it is actually getting close to possible for a reasonably
| senior tech employee.
|
| [full disclosure: no affiliation]
|
| https://www.azura-marine.com/aquanima-45/
|
| https://www.silent-yachts.com/silent60/
| mattlondon wrote:
| I've always been kinda fascinated by this solar yacht concept.
|
| I wonder now with post-covid remote working options and
| starlink if you could actually make it work.
|
| I do wonder though if sailing the ship is basically a full-time
| job in itself (navigation channels? Docking at foreign
| countries? Getting food etc?).
| zdragnar wrote:
| I thought starlink didnt work for mobile connections? I.e.
| that it had to be registered and operated at a fixed address.
|
| That said, unless you are able to drop anchors, I am guessing
| that you would spend most of your working hours at a dock or
| with a partner piloting instead.
| noitpmeder wrote:
| I believe this is only temporary and SpaceX has announced
| plans to roll out different subscription plans (including
| roaming) in the future.
| baybal2 wrote:
| > I thought starlink didnt work for mobile connections?
|
| It will not work either far away from the shore.
| noitpmeder wrote:
| Again I have to believe this is only a temporary
| restriction.
| ncmncm wrote:
| SpaceX are launching satellites with ("frickin") lasers
| now. So, if you are in the middle of the ocean, your
| packets step between satellites on the same orbit,
| forward or back, until they get in range of a node. First
| actual use is for polar service.
|
| On certain routes, packets will be artificially delayed
| so that high-speed traders can pay big bucks to get their
| packets through first, ahead of fiber. And, maybe pay
| even bigger bucks to prevent their competitors from
| getting their packets through as fast. Imagine tiered
| pricing, where each millisecond ahead of the rest of the
| pack is ten times the price.
|
| So, for example, orbits inclined near 70 degrees pass
| near New York and London/Frankfurt. Packets going by
| satellite laser links can get there many milliseconds
| ahead of those poking along on subsea fiber. Somebody in
| London who finds out 10 ms before everyone else about a
| price change in New York gets to make a killing trading
| on the exclusive information.
| dragonsky67 wrote:
| There is a whole world there I do not know and don't
| really want to. What a strange world we live in.
| Stevvo wrote:
| I have a 38' steel sloop with 400w of solar + a wind
| generator on-board.
|
| I'm not a full-time liveaboard, but I have been on-board for
| the last couple of months and you can definitely make it
| work.
|
| Sailing is labor intensive, but not in the ways you imagine.
| Navigation, docking and provisioning are all straightforward.
|
| Where it can sometimes feel like a full-time job is
| maintenance. Everything on a boat wants to break all the
| time. Doesn't matter if the vessel is brand new or 40 years
| old; finding a balance between maintenance and life is
| difficult.
| goldenkey wrote:
| I learned a few years ago about barnacles, which by virtue
| of being unaerodynamic and super heavy if you let them form
| huge colonies on the bottom of your ship, can decrease fuel
| efficiency severely. I saw how much work maintanence was, I
| said 'nope!' I guess a house is similar in some ways.
| Shingles don't last forever, pipes get corroded. The salty
| sea though, it's a bit more unkind to things, aye?
| rootusrootus wrote:
| At least with a house the timeline is long and it's easy
| to hire someone to do it for you. Even galvanized pipes
| last 40-50 years without much problem, and newer pex
| pipes may last indefinitely. Roofs are 25+ years.
| llbeansandrice wrote:
| Not soaking your house in salt water really helps with
| longevity I've found
| Tepix wrote:
| Why wouldn't you use the wind energy also? It's a lot of fun,
| readily available and a lot cheaper...
| oefnak wrote:
| The second link of the parent comment describes a optional
| automatic parasail tug.
| jjcm wrote:
| From the images on the site it looks like it deploys a
| sailing kite in addition to the solar powered engines.
| KineticLensman wrote:
| Oh hi jjcim. Another cool research project from where I
| used to work. [0] Back in the day, the development building
| had a great view of the runway during the Farnborough air
| show and my pals on the Zephyr project would give me a
| shout if anything interesting was taking off.
|
| [0] https://en.wikipedia.org/wiki/Airbus_Zephyr
| Retric wrote:
| Sails have several major downsides, most notably they take up
| a lot of deck space and cause a boat to tilt to the side. If
| you're regularly sailing long distances it's much faster but
| top speed isn't that big of a deal when your living on the
| boat full time.
|
| Other options like kites and wind turbines can work well but
| they all all significant upfront costs as well as ongoing
| maintenance issues. Spending that same money on a bigger boat
| gets you much more space, and of course a generator can give
| you redundancy or higher top speeds.
| jws wrote:
| _...cause a boat to tilt to the side..._
|
| This is a net positive. The alternative is to roll back and
| forth with the waves. It's much nicer with the sail up and
| ata bit of a heel.
|
| Also, just to throw this in, one of the world cruising
| sailing couples which wrote for the magazines switched to a
| diesel powered boat as they aged and found that they spent
| less of fuel than they had on new sails. Sails are
| consumables if you care about performance.
| silisili wrote:
| Interesting last point...curious why is that? Do they get
| battered from weather and physically tear, or do they
| just stretch/thin over time?
| lstodd wrote:
| The alternative is a catamaran.
|
| Your point on the diesels still stands. Properly designed
| cats are unsinkable and don't readily capsize, but not
| weathering a storm is worth every penny invested in
| diesels. Besides one needs them in marinas anyway.
| _ph_ wrote:
| Electrical engines are more and more becoming a thing,
| especially for sail boats, where they server more for
| harbor and anchoring than covering distances.
| Fiahil wrote:
| > Sails have several major downsides[..]
|
| Yes, but it makes less noise.
| Jeff_Brown wrote:
| Also less disturbing to the ecosystem below than a prop.
| pbhjpbhj wrote:
| >top speed isn't that big of a deal when your living on the
| boat full time.//
|
| If you're living on your boat 365 then I imagine avoiding
| severe weather becomes more important?
| bumbada wrote:
| This is the reason Weather reports and forecast are so
| important for people on boats.
|
| Most people living in boats actually live on ports and
| don't get very far from the coast most of the time.
| Stevvo wrote:
| You know, sailing catamarans are a thing, right?
|
| Wind is more consistent than sunshine.
| stareatgoats wrote:
| Sure, I know sailing catamarans well (via Youtube vids mostly
| admittedly). But I switched drooling focus when these things
| started appearing- I suspect they will eventually displace
| many if not most other boat types (albeit not in my
| lifetime), possibly using hydrogen (not battery packs) as
| energy storage. Sunshine is not required if I understand it
| correctly. No wear and tear on the sails, not dependent on
| winds to go from point a to b, more like driving than
| sailing, except no pollution, no noise.
| rektide wrote:
| anyone else think it would be super damn fun building solar
| floating homes like this?
| pcardoso wrote:
| A local company does this, but they are intended to be mostly
| stationary.
|
| https://www.waterlilyboats.com
| mariusseufzer wrote:
| I'd be down haha - When do we start?
| agustif wrote:
| If sea levels keep rising a lot of coasting could be like
| this.
|
| In the netherlands they have flaoting houses in the canals,
| but stationary AFAIK
| bserge wrote:
| There's a couple living on a cheap ass floating tent/home
| (it literally uses barrels to float) in Sweden I think.
| Pretty cool. Also narrow boats in England are cheap and
| rather nice. Could start there.
|
| https://youtu.be/jljkK9HMa44
| pjc50 wrote:
| You definitely want to try an English narrowboat before you
| start. I know people that have done this; it's romantic,
| but at its least romantic you're living in a not very well
| insulated damp trailer.
| notahacker wrote:
| I'm on board mine now! I guess the theoretical benefit of
| the seagoing version is your roof space isn't constrained
| by the size of English locks so you might actually be
| able to fit enough solar to power the vessel. That and
| find good weather...
| kwertyoowiyop wrote:
| It's so depressing to read that one proposed mission for this
| plane is...monitoring oil spills.
| pvarangot wrote:
| I worked on a satellite imaging startup. For this kind of stuff
| usually oil and gas and large scale agriculture are the first
| ones to show interest. They don't need great resolution or
| revisit times and their assets span over very big areas so
| monitoring from the ground/sea or with small drones is really
| expensive.
| esel2k wrote:
| Depends on the appplication. An NDVI analysis or determining
| vast crop / growth problems yes but if you want to check for
| disease this is often done by drones to have higher
| resolution. I could imagine doing regular field visits with
| these planes and avoid the high labor costs of drone
| management/flying.
|
| Sources: I work in a big agtech company with satellite
| imagery. PS: We should connect.
| pythonaut_16 wrote:
| Why is that depressing? Unless you have some silver bullet to
| remove the need for oil or prevent any future oil spills it
| seems like creating innovative technologies to detect them as
| soon as possible is a good thing.
|
| It would be like if someone developed a cheap, non-invasive
| technology that could detect cancer extremely early, and then
| you complained because they hadn't cured cancer instead.
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