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Canadian Company Plans Solar-Powered Heavier-Than-Air Airships
savuporo writes "By crossing airships with airplanes, Solar Ship is planning to build a craft that can carry heavy loads long distances with a tiny carbon footprint. Filled with helium, they soak up rays from the sun to provide the energy for forward motion and fulfill its original design challenge – carry 1,000 kilograms (2,205 lbs) of payload 1,000 kilometers (621.4 miles). The craft is heavier than air, and uses a combination of helium filling its interior and its lifting body delta wing shape to stay airborne. Solar Ship shows plans for a range of different size craft for different duties."
...more ways to waste helium.
Aren't we losing Helium at a rapid rate? How much energy will be required to manufacture more Helium? (If that's even possible)
I was expecting... something a bit more.
It doesn't use up the helium though .. once it's filled it's full.
Second.. from Wikipedia "In 1996, the U.S. had proven helium reserves, in such gas well complexes, of about 147 billion standard cubic feet (4.2 billion SCM).[80] At rates of use at that time (72 million SCM per year in the U.S.; see pie chart below) this is enough helium for about 58 years of U.S. use, and less than this (perhaps 80% of the time) at world use rates, although factors in saving and processing impact effective reserve numbers. It is estimated that the resource base for yet-unproven helium in natural gas in the U.S. is 31–53 trillion SCM, about 1000 times the proven reserves."
Even if they are wrong by a factor of ten that still gives us a few centuries of helium left .. by which time hopefully we'd be either creating helium via nuclear fusion power plants or able to bring back abundant quantities from Jupiter.
They could fill it with hydrogen.
Out of curiosity, slashdot community, is there any material strong enough to hold a vacuum, with a membrane thin enough so that the overall density is less than that of air? Perhaps with some reinforcing (very thin) "bars" to keep it from collapsing? It would mean no need for helium.
Oh the humanity...
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
It doesn't use up the helium though .. once it's filled it's full.
Yeah, I kept those party balloons I got at my 15th birthday, I reuse them every year and they're doing great...
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Shoot. Prior art from the 1600s. http://en.wikipedia.org/wiki/Vacuum_airship
Depends on whether or not you want to put humans in it. Considering airships are pretty slow and humans are pretty impatient, this would probably be used more for cargo.
404: sig not found.
I would not be able to visualize the distance without it.
Short answer: no.
Longer answer:
It's very difficult to achieve a vacuum in the first place. If there is even the slightest leak the air will be rushing in with the force of a one atmosphere pressure difference. With a lighter than air gas the pressure difference is quite low and any leak can be handled with a periodic "topping off" to keep out the air. Even if we had the technology to produce a "vacuum ship" it would not likely be cost effective since the lift gained by a pure vacuum is very small compared to that of helium or hydrogen gas.
An envelope that held a vacuum for lift would be under considerable forces. There is the force of holding back the outside air. There is the force of the gondola which carries the cargo. There would be wind, birds, stupid rednecks shooting at it, among other things that would try to punch holes in it or rip it up. It's just not practical.
I am armed because I am free. I am free because I am armed.
unless we've been fusing helium or annihilating it with antihelium...all the helium thats ever existed on earth is still here (it doesnt even bond to things for the most part!)
yeah yeah its all in where it is located...that's nothing like the problems facing oil supplies. burn a gallon of gas and it no longer exists chemically and physically (barring slight of hand or processes that take millions of years)
PS: I don't reply to ACs.
there's a 30 ton model...should be enough for the truck replacement problem.
PS: I don't reply to ACs.
I would love to know this. My physics isn't great, but I did a quick Google.
It looks like the consensus is that it is not possible, those materials do not exist.
The other thing is that is would not make much difference than using helium:
Density of air is 1.2 kg/m3.
The density of helium is 0.166 kg/m3.
If we had a balloon filled with air, and replaced it with helium, the density reduces to 14%. This means that that much helium could support 86% of the weight of the air. A vacuum's density is 0, so it was possible it would support the weight of 100% of the air it 'displaced'. So a perfect vacuum is only 16% better at lifting (in air) than helium is.
Iran recentyl claimed to have discovered massive helium reserves:
http://www.google.com/search?q=iran+helium+reserve&site=universal&tbs=cdr%3A1&cd_min=9%2F1%2F2011&cd_max=
Allegedly the estimate is 10 billion cubic meters. That was in September, but there's still no mention in major Western media.
This post contains no rudeness or derision of any kind. All arguments are friendly. Terms and exclusions may apply.
As long as we're in fantasy land, why not get it from the Sun ? It's a lot closer.
of helium!!! and hydrogen!
The german company CargoLifter tried to build huge airships that carry up to 160 ton payload.
http://en.wikipedia.org/wiki/CargoLifter
On top of that, a vessel holding (?) a vacuum has to hold back considerable pressure. That's not going to be light. Would make a neat physics demo though, two bottles, one with the air sucked out on a scale.
404: sig not found.
If the aircraft needs no fuel to stay aloft what is placing the limit on the range? At some point it would have to come down of course but why couldn't it stay up for 10,000 km instead of just 1000 km?
Lifting body aircraft with lighter than air gas to assist in lift has been tried before unsuccessfully. This is different in using solar power to drive the engines. With the low density in solar power I find it difficult to believe solar power is enough to keep the aircraft aloft. Perhaps that is where the range limitation comes in, there is only enough battery power + solar power to stay airborne for 1000 km.
Given the current technology in batteries and photovoltaic panels I'm tending to believe that a coal burning steam engine makes about as much sense in aircraft. I'll have to do the math but the power to weight ratios might just be comparable. I'll guess the coal burning would not go over very well with the global warming crowd. Perhaps a steam engine that burns wood, hemp, switchgrass, sugar beets, or some other biomass would be more acceptable and still keep the power to weight ratio within the same ball park as an electric battery pack.
I'm pleased to see technology like this getting some attention. I think that airships will make a comeback as energy prices rise and material science improves. I'm just a bit of a skeptic when it comes to solar power.
I am armed because I am free. I am free because I am armed.
If it is heavier than air, it aint floatin no-where.
The ship is heavier than air, helium isn't. And because of it's small size, helium can escape through the tiniest leaks. Most likely, the airship will require regular helium refills. Once helium is in the atmosphere, it's too hard to purify, and it will also leak into space.
The short answer is no. At one atmosphere of pressure, any structure would either be too heavy or be easily crushed.
An interesting question to the geek community... maybe crunch some numbers... Is a vacuum sphere that only operates at extremely high altitudes and low pressures feasible?
caracal for the small version? a "mothership" for the vastly larger version? someones been playing EVE online.
WÌÌfÍ--ÍSÌÒÍ...Í...ÌHÌÍfÍÍÍ--ÍÍÍ
Depending on how the buoyancy compares to loaded weight, deadheading might be impossible. You'll have to carry huge concrete blocks on the return trip just to keep from launching yourself into space. This could lead to very low one way costs for cargo transport between certain locations.
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But since it is a lot hotter in that direction, all those missions to the sun would have to be done at night.
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The interesting thing is that, if they are mylar (or 'foil') balloons, you could do just that. It is the latex, and most plastics like polythene, that leak helium.
Prediction for end of Universe #42: Fencepost error in Quantum_bogosort.cpp
Hmmm... There's less buoyancy in thinner air so you need to displace more of it meaning a bigger "vacuum sphere"... I don't know the numbers but my intuition tells me this won't work.
404: sig not found.
Mylar party balloons will typically only hold enough helium long enough to float for a couple of days.
http://www.johnmcphee.com/deltoid.htm
Why is Snark Required?
Interesting thing for them to try. Kinda similar to the airships in Soft Targets by Dean Ing.
Um, last I heard, didn't George Bush decide to sell of the bulk of the US helium stockpile, at below market rates?
Helium is a very fiddley gas. Not only are it's atoms tiny, tiny things, but they don't even form molecules like hydrogen has the decency to. They'll easily seep out through even the most apparently impervious materials - that's why party balloons deflate. The only way to contain it is a thick-skinned container, which would be very heavy.
It would be roughly equivalent to a submarine at 10m, right? That said, building the pressure hull of a submarine isn't cheap. Of course, a sub can take 10 or more atms, not just 1.
How about something like aerogel, only trapping vacuum rather than air? It's be prohibatively difficult to manufacture, if it can be manufactured at all, but could it be done in theory? Need a specialist in materials engineering to determine that.
As other posters have mentioned, Helium is in more or less finite supply, and any released into the atmosphere is irrecoverable. Additionally, due to USG's selling off of their strategic reserve, it's also artificially cheap at the moment.
Unfortunately, I understand Helium to be actually essential for superconductors at the moment (and hence MRI machines, particle accelerators etc.) so any other usage (Airships, kids' party balloons, this project) is a massive waste.
A flying submarine? ;) You know they are design to withstand several atmospheres of pressure.
Note that this is a Canadian company.
There are lots of places in Canada that have no roads or very poor quality roads. The same can be said of a number of other places around the world.
If you are moving a thousand trucks a day it is probably worth it to build a thousand miles of road to accommodate them. If you are moving the equivalent of one truck every three days to a camp that changes location every three years, it is probably NOT worth it, and a cargo airship may well be the most cost-efficient choice.
http://www.hybridairvehicles.com/
The US military is buying half a billion dollars worth of kit from them... Or rather through Northrop Grumman.
http://www.flightglobal.com/news/articles/video-northrop-grumman-wins-race-to-revive-hybrid-airships-with-517-million-order-343259/
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More importantly, water has a much higher density than air (10 meters of water give the same pressure as the whole atmosphere!) and therefore gives a much larger lift. Which means much heavier constructions still get sufficient lift to swim.
The Tao of math: The numbers you can count are not the real numbers.
Just clone Al Gore.
There's your inexhaustible supply of hot air right there.
You can't trap vacuum because vacuum is not a substance but rather the absence of substance.
The Tao of math: The numbers you can count are not the real numbers.
You can still trap it. You just need to use a container to keep gas *out* rather than in.
As a robotics person, I really, REALLY, want to see autonomous variants of these. I imagine it already has some kind of GPS onboard that would be the primary means of navigation. The rest is basically a much easier version of all of the design challenges of Google's self-driving cars. You see the runway to take off/land the same way the cars see lanes on the road. You can interface with existing air traffic control infrastructure instead of dealing with the chaos of public roads.
There's absolutely no reason we shouldn't have these flying themselves all over the place carrying cargo that's normally (in the US/Canada at least) shipped via truck or rail. If the speed estimates people have come up with here based on the range are any good, shipping time would be reasonably competitive given that aircraft don't have to deal with road traffic, weigh stations, etc.
Which school is training these morons who spew out this "after the break" / "after the jump" nonsense that plagues the web these days?
$ man 8fun nuke # might contain proper commands for helping them...
OK, I'll do the engineering then.
10L of air (the inside of a SCUBA tank) weights 12g. A SCUBA tank can hold 400 atm, and weighs about 15kg (note, this is generous). Everything involving pressure tanks scales linearly, so you could have a 10L tank holding 1 atm and weighing 37 grams, displacing 12 grams of air, for a net of -25 grams of lift.
So you need materials about 3 times the strength/weight of good SCUBA gear, preferably 6 times (so you can actually get a noticeable amount of lift). That's assuming there's no challenges in manufacturing much thinner but much lighter tanks. Oh, and that buckling won't be an issue (since we've moved from tension to compression) - that can be solved my making really small tanks, but then you are trying to make the walls very very thin.
You're right - it wouldn't be easy.
And most submarines are too heavy to float in the air.
Would it possible to build something like this held up by the buoyancy of hot air rather than helium?
With the right kind of insulating materials in the envelope, heat loss could be controlled. There might also be a way of using solar power to heat the air.
Stick Men
What is it doing in a storm - can it dodge by rising above?
Monorail... monoraiiilllll... MONORAIIIIIIIL!
don't need thick just dense. just line the helium tank with a lead or gold foil.
i thought once I was found, but it was only a dream.
Aerogel has a density of about 30g/l, whereas air has one near 1g/l. Aerogel is far too heavy.
As long as we're in fantasy land, why not get it from the Sun ? It's a lot closer.
I was going to say because of the gravity well - it is much harder to lift things from the Sun's deeper well.
But then I remembered we were talking about helium, so you can just float it up. Getting it down to ground level from earth orbit is the hard part.
Which is fine apart from the microscopic cracks that form from the stresses of wind force, acceleration, thermal expansion and changes in atmospheric pressure. To helium, a microscopic crack might as well be an open door. Maybe if you laminated plastic and lead... but that would be a material like mylar, which is already used in party balloons and doesn't hold helium for more than a few days at that scale. It's possible such an approach would work, but it would require the development of a completly new containment composite material.
His patent application was eventually denied on the basis that it was "wholly theoretical, everything being based upon calculation and nothing upon trial or demonstration."
If only the patent office still thought this way, maybe we could do something about the patent trolls (at least the ones who generate their own patents, the ones who buy others patents already granted wouldn't be affected).
This is my sig. There are many like it but this one is mine.
"It's very difficult to achieve a vacuum in the first place"
Maybe that Dyson guy can have a go at it, he seems pretty good at designing vacuums
It doesn't leak out through the mylar though, it leaks out through the cheap-ass seams and the badly tied knot at the bottom.
If you get a good one they can float for months (I had one that did...)
No sig today...
I thought this, too. Surely we're at the point (technology-wise) where hydrogen is viable for airships.
No sig today...
Cargo is what they're proposing, yes, and given the number of containers that fall off ships every year I suspect the risks of using hydrogen would be *less* than sending it by sea.
Building airships sounds a lot cheaper than building container ships, too. Those things are expensive.
No sig today...
Oh the humanity...
The Hindenburg "disaster" to which you allude only killed 36% of the aircraft's occupants. To me, that seems a pretty good survival rate, given that a 747 hitting any obstacle very rarely results in a mortality rate of less than 100%.
But the same problems would face the designers of a large airship. The helium may not leak through the skin itself, but it will be challenging to keep all the seams tight enough to prevent leakage. Also, after a while, microscopic cracks could develop due to flexing and bending in the wind.
Right after I posted that I remembered about things called 'parachutes'. Surely a modern passenger airship could be fitted with a parachute system which triggers if fire is detected so you float gently to the ground.
No sig today...
Isn't there a helium shortage?
Ok all of this is pointless because nothing is perfect and eventually the helium will leak out and at our current rate of consumption we are going to run out of helium within our life-times so...........bad idea, not going to work, move on.
A fully loaded truck traveling 1000 km uses just over 4 gallons of fuel per 1000 kg it carries. 4 gallons of fuel is not going to affect the shipping price that much. Once you factor in replacing any helium lost and the salary difference between a truck driver and a pilot, I doubt this will be cheaper. Plus, the truck can travel through storms and high winds (except the most extreme examples of both) and drop off it's freight anywhere there is a road, does not need a ground crew to park, and will have minuscule amounts of maintenance & certification costs compared to an airship. No mention of what speed this will travel either, but I guess it wouldn't be very fast given it's power source.
There will probably be a niche for this, but I don't see this replacing current shipping methods much, except to very remote areas.
Why ? Even if the helium is going to run out, we could still waste it for a few more decades.
...although one already explored by SF authors such as Norman Spinrad in Songs from the Stars. 1000 kg weighs 2200 pounds and is basically the load of a pickup truck. By far the easiest way and cheapest way to get a load 1000 km is to build a solar powered electric railroad, especially if you don't care how fast it gets there at first. Of course, with solar collectors on the ground, there is basically no practical limit to the power you can deliver per kilogram and consequently one can get the load to destination at very high speeds with a new design.
The difficulties with a solar powered helium dirigible are manifold and have already been pointed out -- finite supply of helium, helium needed for kids' balloons and (eventually, perhaps) as thermonuclear fuel (at which time we'll kick ourselves for wasting it for decades in kids' balloons), absolutely impossible to keep sun-warmed helium inside any sort of bag. Weather and wind make the transportation dangerous or impossible (given the wimpy peak power likely to be available to move the bag -- probably inadequate to overcome even a very modest headwind). The danger of 1000 kg loads being dropped on people's heads if weather conditions exceed the limited capacity of robot brains to solve weather problems and the lifter breaks up, pops, catastrophically fails.
It isn't quite inconceivable that one could build a solar-solar system -- a solar balloon for lift, solar power for "thrust" -- although again I think that the force of wind pressure instantly will exceed the peak thrust of any onboard solar system on even a very sunny, nearly still day. To lift a metric ton you'll need a rather large balloon, so very small overpressure on the upwind side will exert a huge force downwind. And you'll still have the problems with weather, with the fact that the sun doesn't shine at night and you can't carry batteries or the whole design becomes laughably impossible, not marginally feasible (either one, Helium or hot air).
But rail? Piece of cake. Hell, you could probably deliver a steady stream of pickup truck sized loads driven by solar collectors along the roadway -- 70-100 watts per square meter of collector, plenty of room for 1000 watts per meter of actual track along the 1000 km route. In fact, the track (with a mere 12 meter wide roadway, 2 meters of which is track and vehicle) will generate anywhere from 100s of megawatts to a gigawatt of power on any reasonably sunny day. Assuming 10 kW per metric ton to move payload at 100 km/hour or better, one can move anywhere from a minimum of 10,000 metric tons up to a maximum of 100,000 metric tons per 10 hours of useable daylight day, for the amortized capital cost of the solar powered roadway. (Don't whack the math too much, these are all estimates and YMMV). The cost of the solar electrification is currently a bit over $1/watt, installation and collection will double that. Call it a $5 billion project (the cost of a couple of weeks in Iraq), build it on an existing rail corridor between (say) Detroit and Chicago square in the heart of the industrial heartland. If one charges $10/ton for transport (pretty cheap, one would think) it grosses close to $1 million/day running the rail at capacity, $300 million a year, payback of the initial investment in 15-20 years.
As is so frequently the case in solar projects, this is maddeningly close but not quite a cigar. For a billion dollar investment it would be a no brainer -- payback in 3 years (more likely 5 with operating costs), pure profit thereafter. For 2 or 3 billion dollars it is attractive -- an effective yield of maybe 5-10% on investment in the long run. For 5 it is right down there at 1-3% yield, implying a fairly long period to wait for a not-too-large ROI, plenty of risk. Drop the cost of solar cells by one more factor of two and it will happen all by itself. Drop it by a factor of four or more, which is entirely plausible given sufficient volume in the market (and this project alone would consume
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
I've just gotten a image of this huge airship on fire with an even bigger parachute dragging it upwards under the updraft from the fire.
hmm, you could put some radioactive waste in the center of a huge balloon. As the air in the balloon heated up you would let air out of the balloon until the pressure stabilized and lift was achieved.
Huh? It's not helium or hydrogen or vacuum that generate lift, it's air pressure.
The lift generated is proportional to the amount of air you displace, it doesn't matter what you displace it with.
WTF is an air distillation plant?
Normally you distill liquids, so to distill 'air' would be a cryogenic operation,.very expensive in money and energy.
Like we have some kind of spacecraft that can make it to the sun and back in one night? No, we'll have to wait for the winter solstice and go from the North Pole. That'll give us plenty of time for the round trip.
I hope you're joking. Of course helium doesn't 'float' -resist gravity- but it does rise (get pushed) to a point of lower density when mixed into an atmosphere. Like bubbles in water...
-- thinkyhead software and media
Unworkable, then. Oh, well, it was an interesting idea. Maybe it'd be of some use in even further improving the already-impressive thermal insulation property, but it's not going to lead to any lighter-than-air solids.
Yeah, that's pretty obvious. For one thing, we know enough now not to paint the skin with rocket fuel.
IIRC, hydrogen is more buoyant than helium.
Yep, but his point was semantic. Rather than say "trap a vacuum" it's more accurate to say "create a vacuum" and even more accurate to say "remove all substance."
I think what you mean to say is "bullshit to me," or more accurately, "neither of which I comprehend."
There, fixed that for you!
I was thinking of the initial free-fall before the parachute opens. It'd be bit like the dropship scene in Aliens.
(Anybody who posts the quote will be modded down...it's not clever...we all know it)
No sig today...
Sorry but your comments show a fair amount of ignorance of the country where this aircraft would operate, and the reasons why it is even being thought of. It's too bad that you spent so much time looking up numbers like ROI that simply don't apply here.
To build a solar-powered railway as you put it, that would reach the places in Canada that such an aircraft of this type would reach, would cost many billions of dollars more than the development of this aircraft would. Even worse, you cannot actually build a railway to these destinations. Think about huge diamond mines in the middle of the tundra. Or remote arctic communities. If we could have roads and railways to these places, don't you think they would already exist? We're talking thousands and thousands of miles of tundra and wilderness that would have to be crossed. Have you watched ice road truckers? You can't build a road on tundra. Nor could you lay track. Right now the only way in or out of these places to which this aircraft would go is by aircraft in the summer, and if it's possible to reach in the winter, by snow mobile, dogsled, or crazy ice road trucks.
This airship concept has been under study for quite a number of years. It may not turn out to be feasible. But if it is, it will be a boon to Canadian citizens living in these remote places, and to the many companies who mine natural resources in the far north.
The apostrophe is a very fiddly symbol. Not only is it used to indicate possession, but it can be used for a contraction. Most people don't have the decency to learn the difference. They easily know every programming concept and physics trivia, but the difference between ITS and IT IS is beyond most people.
You've effectively described NASAs new LEO lifting system. It's genius.
Maybe if we contained the helium from the nighttime sun in some sort of container, like a huge plastic bag, and used an abundant substance like sand as a weight, we could just drag it down to the surface of the Earth.
"No matter where you go, there you probably are." -- Buckaroo Heisenberg
Since this is a) a blog dedicated to geeks and b) used by geeks all over the world, do we really need metric being converted to US costumary?, especially when there is a unit that is exactly 1000kg which is close enough for most lay americans to approximate, (tonne).
IIRC, hydrogen is more buoyant than helium.
Hydrogen is half as dense as helium. Trouble is, the number that counts is the difference in density between the lifting gas and the surrounding gas. Run the numbers, and you'll find a hydrogen-filled balloon will lift about 5% more than a helium-filled one.
rj
Russians did a bit of R&D on Ground Effect Vehicles. They seem like a good compromise, albeit they would need docs or large plane roads to reach seas. They would be fast, close to surface and provide better fuel savings due to lower drag. I would really like to see some R&D go into them.
http://en.wikipedia.org/wiki/Ground_effect_vehicle
Let's not forget some of the inteded applications of this. There was talk of these being used to move equipment and supplies into remote northern areas too. Rail and roads are great and all, however in Northern areas in Canada, no such option exists to get anything to these areas and are limited to ice roads in the winter time. The costs of airlifting any of these supplies cost prohibitive, or for what does get up there, almost oppressive in end user costs:
http://eyeonthearctic.rcinet.ca/en/news/canada/45-society/702-29-cheez-whiz-food-prices-skyrocket-under-canadas-nutrition-north-program
i don't... because i don't memorize useless fucking trivia
As long as they don't paint it with rocket fuel, it'll be fine.
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
You just troll all the livelong day.
I'm sure it could be done, but it wouldn't be trivial. For cabins of a reasonable size, I'm thinking something like a 737, a single parachute would probably not be feasible for size reasons (I'm just guessing here though), and with multiple parachutes it would have to get more complicated. In the end it would be risk versus reward. Cost of development would be very high assuming you actually wanted to test it, and it wouldn't instill confidence in people to know that hey we felt an accident was so probably that we spent all this money on parachutes.
Actually the helium shortage is strictly a manufactured shortage, created by the US Government when they (principally the Navy) decided blimps were not its platform of choice. The Government decided to dump its huge reserve of helium at submarket prices, and as such nobody bothers to extract helium from all the natural sources where is has historically been obtained.
Government passed a law shutting down the helium reserve. The law stipulates that the US National Helium Reserve, which is kept in a disused underground gas field near Amarillo, Texas – by far the biggest store of helium in the world – must all be sold off by 2015, irrespective of the market price.
There could still be as much helium produced today as ever, were it not for cheap government surplus sales, as it is, nobody bothers to extract it.
See article here:
http://www.independent.co.uk/news/science/why-the-world-is-running-out-of-helium-2059357.html
Sig Battery depleted. Reverting to safe mode.
I forgot about the polar angle. And since the northern and southern hemispheres have their winters at opposite times of the year, then we should be covered for even more time.
I have a friend who can work out the details, but I don't know when she will be available. Last I heard she was stuck at the mall. There's a big power outage going on there today, and she is stranded on the escalator.
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Helium is very difficult to confine even in industrial conditions.
"This post is an artistic work of fiction and falsehood. Only a fool would take anything posted here as fact."
what's the Helium footprint?
It's a little known fact, but Russians have used vacuum for many years for these kind of purposes. The problem is that it leaks pretty easy, so you have to keep a large supply at hand. Russians solved it by liquefying vacuum so that it takes less space, and can be conveniently trucked around in vehicles like this one, or even stored onboard for quick resupply.
Unfortunately, liquid vacuum is a dangerous substance that's quite tricky to store, so accidents happen. As usual, Soviet technology basically disregarded personal safety of the crew for the sake of higher efficiency.
It was the "Helium Privatization Act of 1996", which would have been passed by the Republican congress at the time and signed by Clinton:
http://en.wikipedia.org/wiki/National_Helium_Reserve
It usually only takes a moment to verify something you "just heard", and it really helps to avoid the echo box effect.
So what's lighter than helium and hydrogen? Vacuum! We need more advancements in vacuum balloon technology.
Interesting, I had always heard there was a 20% difference. Wikipedia has calculations showing 8% (sea level at 0C) which is much closer to your number:
http://en.wikipedia.org/wiki/Lifting_gas#Hydrogen_versus_helium
That calculation there looks altitude invariant; perhaps the difference that leads to your 5% is due to non-ideal gas behavior of air at altitude or something like that? I'm curious.
Also I wonder if the 20% was for a given size of balloon where they factored in the extra envelope size, additional support, and everything else that snowballs from starting at an 8% penalty.
Thank you for the reminder, and the link. I'll try to do better.
OK, the 5% number was a memory from an earlier discussion on the same subject, so it could easily have been 8%. I'll run the numbers tomorrow.
Anyway, the load the balloon can lift is the difference between the weight of the gas in the balloon and the weight of the same volume of the outside gas. Non-ideal gas behavior, no...at 1 atm pressure and any reasonable temperature, all three gases are very close to ideal gas behavior.
rj
but this kinda strikes me as a cross between an airplane an a barge. Another way of saying it would be it's like an airborne railroad
Both aren't as fast an an airplane, but both can carry many times as much weight and can travel a predictable distance very affordably on an item-by-item cost basis..
"Don't be a martyr -- BE THE ONE WHO GOT AWAY!"
Hip hip hurray for alpha decay!
So you are replacing the limited non-renewable resource of oil, with the limited non-renewable resource of helium?
Though it would slow the consumption of oil, so it might be marginally useful.
I guess for me, is the benefit really worth the effort. You are offsetting the crappy efficiency of solar power, using the buoyancy of a limited non-renewable resource of helium, so you can burn less limited non-renewable oil basically.
This might serve as a limited stop gap measure for awhile once oil prices have skyrocketed, but I don't see much demand before that.
You could design it with "lifeboats" that are parachute and airbag equipped. Then you only have to worry about supporting the weight of the passangers. Since they'd just drop out of the bottom, you wouldn't need as much time to launch them as a ship does.