The Second Age of Airships 363
The Telegraph has a story about a new generation of airships. It says "It's a new vehicle. It's a hybrid because we're combining helium lift, aerodynamic lift, a hovercraft landing system, and vectored thrust... If you can get beyond the word airship — because that has a lot of history — people think about them differently."
Great, instead of peak oil ... (Score:5, Informative)
we'll have peak helium.
http://news.slashdot.org/story/10/07/05/2159215/Price-Shocks-May-Be-Coming-For-Helium-Supply?from=rss [slashdot.org]
Re:Great, instead of peak oil ... (Score:5, Informative)
Technically we hit peak helium a long, long time ago. Most of what's used today is out of storage collected decades ago.
Re:Arrogant prick (Score:4, Informative)
Airships make more sense for transporting cargo than people. They let you bypass the bottleneck of a port and let you take the cargo directly to its destination.
Not the first try to revive airships (Score:5, Informative)
Half as dense != twice lift (Score:5, Informative)
The other problems with hydrogen are (a) that it leaks out of just about everything even faster than helium does and (b) your safety statement is utterly unproven - because nobody has recently built full size airships and compared the safety record to current winged aircraft, which are quite extraordinarily safe. Historically, airships in the 1930s might have been safer than airplanes - but since then airplanes have had over 70 years of technical advancement which have paid off massively.
Hydrogen or hot-air (Score:1, Informative)
Re:Great, instead of peak oil ... (Score:5, Informative)
Having usable amounts of helium trapped in one place so you can collect it efficiently is quite rare though. There's a reason that > 90% of helium was taken out of the great plains, it's one of the few places where it occurs in large enough quantities to be feasible. There are, of course, other places (Algeria apparently is the new number 2 producer according to Wiki), and as the price increases it will become more economical to capture and refine from natural gas wells that ignore it today. That's one of the reasons there was a big push to stop government control of the price of Helium, it's important that we start collecting more of what's available before we vent a potentially precious resource into the atmosphere because its too expensive to capture.
Re:Great, instead of peak oil ... (Score:5, Informative)
It is not like alpha emitters are a particularly rare thing...
No. The problem is that the alpha emitters have half-lives in the billions of years. While there's plenty of helium being produced inside our planet, the problem is one of venting. No one is willing to stand over active volcanoes to collect it for some reason. The helium that comes up through permeable rocks in the crust can't be collected because it's so diffuse. So we're stuck with those helium pockets that can be collected - those that happen to be trapped (along with natural gas) under rocks that aren't permeable. Those pockets took - billions of years to create, and dozens of years to empty.
Re:Great, instead of peak oil ... (Score:5, Informative)
Re:Use hydrogen. (Score:5, Informative)
Oh, jeez, the "rocket fuel" BS again. Might want to read this:
http://www.airships.net/hindenburg/disaster/myths#flammable-cover [airships.net]
rj
Re:Hydrogen or hot-air (Score:1, Informative)
Hydrogen can be extracted using electrolysis or bacteria. That opens up nuclear, hydro, solar, and bio as sources of materials.
Re:Great, instead of peak oil ... (Score:5, Informative)
"What helium is present today has been mostly created by the natural radioactive decay of heavy radioactive elements (thorium and uranium), as the alpha particles that are emitted by such decays consist of helium-4 nuclei. This radiogenic helium is trapped with natural gas in concentrations up to seven percent by volume, from which it is extracted commercially by a low-temperature separation process called fractional distillation."
Looks like another good reason to build LFTR reactors that can also take
the current radioactive waste and dispose it for good.
http://www.youtube.com/watch?v=WWUeBSoEnRk [youtube.com]
Good transition til we can upscale other clean energy sources.
Re:Hydrogen or hot-air (Score:3, Informative)
Lockheed is way ahead with airships (Score:5, Informative)
Lockheed's P-791 airship [youtube.com] has been flying around Palmdale for several years now. This is a product of Lockheed's Skunk Works. It is slightly heavier than air, and those four "feet" are lift fans. This has advantages and disadvantages. It takes fuel to stay up, for one. On the other hand, takeoff and landing are easier; the craft can land on a runway and taxi as a hovercraft. No mooring mast required.
The P-791 looks far more controllable than any previous airship. Rudders and elevators are ineffective at low speed. The P-791 has four propellers, each fully and independently steerable in two axes, plus speed, and maybe blade pitch. Plus the four lift fans. So it is controllable in all six degrees of freedom, even at zero speed. With classic airships, having twenty controls to manage by hand would be hopeless. With flight control computers, it's possible, once the airship has been characterized. That's really what flight tests of the P-791 are for - figuring out the control strategies. In the video,it's clear that the propellers are all being steered independently, which indicates computers and sensors are busily working to stabilize the beast. This is probably an easier job for the Skunk Works controls team than any of the stealth fighters they've done, all of which are unstable in all three axes.
The Zeppelin NT [airshipventures.com] has a similar, but less flexible system, with three steerable fans plus a lateral tail rotor, all controlled by a fly-by-wire system. I suspect that the Skunk Works put more degrees of freedom into their prototype than are really needed, so that they could experiment with different control strategies and find the best way to control their unusual craft.
The Zeppelin NT has a compressor system, so they can reduce lift by compressing some helium into a high pressure tank and letting some of the ballonets deflate a little. This is preferable to dumping ballast or helium.
Re:Hydrogen or hot-air (Score:5, Informative)
Re:Not the first try to revive airships (Score:3, Informative)
Popular Mechanics had a decent article on this last year:
http://www.popularmechanics.com/technology/aviation/airships/4242974 [popularmechanics.com]
I hope the Cardington team gets funding and critical mass, because airships are quite usable for various tasks, and moving one around is a lot cheaper than moving a plane merely because that the lift is provided already. Airships have a lot of practical uses:
1: Transportation of goods across the Atlantic or Pacific. It won't be as fast as a jet, but if done right, will be a lot faster than a freight ship. To boot, the destination does not have to be a port, it can be a city well inland, provided there is right of way through the airspace. It wouldn't be hard to find corridors for airships to travel safely on, although storms may be a risk.
2: Travel to areas after a disaster, even with no airport.
3: Passenger travel. This would be a method of getting people across the US in a decent amount of time, faster than Amtrak. Of course, it isn't as fast as a jet, but would take far less fuel. Of course, the engineering problem would be speed because it needs to be somewhat competitive with regular commercial airline travel to get people using it. Plus, people are used to getting from one end of the US in a day, rather than having to spend a night on a vehicle. Maybe for regional transportation this would be useful, such as getting people from LA to SF and back.
4: Cruises. It would be a gamble, but if someone put the mega (or more accurately giga) bucks into making a gigantic airship that rivaled luxury cruise liners, it might be something people would use for vacations. Perhaps slow trips to another country there and back.
The $50,000 question is getting people to buy into airship technology. It may not be as cool as a Harrier or other VTOL aircraft, but a well-designed airship can do a lot of basic tasks cheaper in the long run than a plane.
Re:Use hydrogen. (Score:4, Informative)
Gasoline burns, hydrogen explodes
No, both burn and either will explode if ignited in an encloded space, just like gunpowder. Take a firecracker and empty the powder out and light it it will simply burn.
Hell, I made the "scientific discovery" that hydrogen burns and not explodes in the seventh grade. [slashdot.org][journal] Where did you get the idea that hydrogen explodes? Mythbusters tanked that one, too.
Re:Hydrogen (Score:3, Informative)
Using the lift tables here
http://www.chem.hawaii.edu/uham/lift.html
Gas Dia. Ft. Vol. l Lift gr. Lift Lbs.
Helium 24 204976.41 210369 463.79
Hydrogen 24 204976.4 228550.5 503.87
503.87/463.79 = ~1.09
so using Hydrogen over Helium is a net gain of ~9% lift.. don't get be wrong but 9% is a lot of extra it isn't nearly 2x aka 100%. I think the added safety of having a Non reactive gas over the most reactive - is worth the loss of extra lift..
Part of the reason Hydrogen doesn't provide the extra lift people think it should is because while in Gas form Helium is just He, Hydrogen is H2 which is still smaller (almost 1/2) in volume than He
Re:Use hydrogen. (Score:3, Informative)
Re:Great, instead of peak oil ... (Score:4, Informative)
"Most of that is used to blow up party balloons."
http://www.nap.edu/openbook.php?record_id=9860&page=27 [nap.edu]
party balloons could come under "pressurizing and purging" or "other" but the vast majority is used in cryogenics, welding or controlled atmospheres.
Re:Use hydrogen. (Score:3, Informative)
Re:Forever. (Score:3, Informative)
Re:Great, instead of peak oil ... (Score:4, Informative)
The way I understand it, we privatized the US supply of helium back in 1996. We targeted selling 850 million scm by 2015, reserving 17 million scm for the federal government's reserve. The price has been set artificially low in order to get that 850 million scm sold off in time.
In other words, we're not approaching peak helium, we're stupidly, deliberately, actively rushing toward it.
http://www.agiweb.org/gap/legis106/helium.html [agiweb.org]
http://www.blm.gov/nm/st/en/prog/energy/helium/federal_helium_program.html [blm.gov]
http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=9860 [nationalacademies.org]
https://twitter.com/timoreilly/statuses/17831735662 [twitter.com]
Re:Safe from attack? (Score:3, Informative)
A few relevant points:
- 20,000 feet is nearly 4 miles. You'd have to have a half-assed tracking system on a half-decent missile system to hit a target 4 miles straight up. An actual rocket-propelled grenade ain't gonna cut it. I'm not saying the tech isn't available, and I'm sure there are shoulder-mounted SAMs that can handle it, and I don't doubt that some insurgent groups might get access to them, but it's not what you can pick up at a Soviet Military Surplus store.
- If you hit anything "soft", your missile is going to punch two small holes through one of the balloons and continue sailing on by, and the thing is likely going to be able to coast to a landing for repairs, or even continue is mission. You'd have to hit something "hard" that would cause your missile to actually explode while inside the envelope or near a control system.
- An airship means there's plenty of cargo space. Including space for things like chaff, jammers, flares, and other incoming-divert-or-destroy sorts of technology. Military people tend to be pretty smart about including these things in their expensive tools if the tools have strategic value.
- The UAV's got good cameras and it's designed to look out, and if there's one there'll be lots of them. The launcher might be able to take out a single UAV, but with multiple eyes in the sky, how long do you think it'll be before that missile trajectory is tracked back to the source and a "return to sender, sealed with a kiss" is made using something very fast, very accurate, and very full of boom-boom? Repeat performances won't be terribly common.
And finally,
- These would be UAV (unmanned aerial vehicles) and, as such, relatively disposable. The military is looking to use airship tech to keep the aloft longer, since they won't need as much fuel just to stay up in the air where they are needed. They'll still be a hell of a lot cheaper than a recon plane, stay on mission longer, and not that much easier to hit. More eyeballs in the sky, longer, cheaper.
And as an aside, the resources expended on purchasing a missile capable of trying to take out something like this would be orders of magnitude higher than what's needed to set a car bomb or planted roadside bomb. In other words, the insurgents, with not unlimited resources, would have to choose between setting a whole bunch of car bombs, or buying one missile. One of these UAVs taken out could actually seen as a sort of perverse victory, since the insurgents expended a LOT of their own resources to get the tools to do it.
Re:Airships simply will not be practical, sorry (Score:4, Informative)
How did this get rated insightful? I guess neither the mods nor you bothered to read the article.
These are hybrid vehicles. They aren't airships or balloons. It's not about lifting payload with gas alone; it's a lift hybrid system. The gas can offset anywhere from the weight of the vehicle to some percentage of the cargo. Thrusters and a lifting-body airfoil shape then provide the rest of the lift. From the research that has been done so far, this is feasible, practical, and economical. At this stage it is also economical to pump helium around to control the gas lift. Some designs use just fans to pump helium from large lifting bags into storage bags. Since the helium is at such a low pressure, it doesn't take much to move it and to change the buoyancy of the entire system.
Really, it's not as hard or as bad as you make out. It appears to be absolutely practical in the long run. And these guys have years of experience in this field now, which you do not, as near as I can see. In fact you just made up the stuff in your comment. Sounds good and logical, but what you said has no basis in the current facts of the field, and is certainly not relevant to the types of airships this company is designing. In the article one of the guys bemoans the fact that armchair airship "experts" such as yourself have a real negative impact on public perception of these hybrid air vehicles and negatively impact their ability to research this stuff.
Re:Maybe if they could focus (Score:3, Informative)
Did the test include shooting at the crew? I'm sure they'll find that sitting nearly motionless over a well-armed enemy does not make airship pilots invincible.
This was a test for military use. The military's plans for use in Afghanistan is for an unmanned, reconnaissance vehicle. No crew required.
Re:Arrogant prick (Score:2, Informative)
Well, they already tried that with CargoLifter [wikipedia.org].
All that came out of that is the Tropical Island [wikipedia.org] in the ex-hangar.
Sorry to cast an umbrella under your rain but... (Score:5, Informative)
(1) one only needs the "modern" technology of the "compressor" to re-compress the gas into dense storage cylinders. They _used_ to vent the gas because the compressors and storage were more expensive and heavy than the cheap replacement gas. Modern technology can solve this really easy. You can fit 80 cubic feet of air (so probably like 100 cubic feet of helium) into a scuba tank, and it would be quite heavy thereafter. Intelligently done, a large number of flexible ballon-like bladders and one or two semi-rigid (pressurized) bladders would be easily sufficient to change the overall displacement of an airship by up to 50 percent without even getting into "high" pressures (e.g. more than three atmospheres or so in the pressurized fixed-size bladders). It's not rocket science, its basic pressure mechanics and displacement.
(2) many of the craft being discussed are only "mostly buoyant", with vectored thrust and lifting bodies etc, so that the static weight of the craft is neutrally boyant, then only the thrust to lift or fly the cargo is spent. E.g. the goal is to make the weight of the _vehicle_ free. Think of the helicopter. Right now we have to maintain thrust to lift the copter and the people, which uses far more fuel than just lifting the people.
(2a) once you are lifting only the cargo weight, crashes are lots safter as something with the weight of the cargo but the drag profile of the whole vehicle will have a much lower in-atmosphere terminal velocity, unless of course someone decided to shape it like a giant dart pointing straight down. 8-)
So, Good Sir Nay-Sayer, yes, if nobody actually thinks about the problem, then ballast becomes a hassle. But then again, if nobody thinks about breaks, a speeding car is quite a problem as well.
Re:Airships simply will not be practical, sorry (Score:2, Informative)
Re:Vaccuum ships? (Score:1, Informative)
Apparently, this idea has been around since the 17th century.
http://en.wikipedia.org/wiki/Vacuum_airship
Re:Speed and mass are issues. (Score:3, Informative)
It won't fix everything, but it will save a few lives, which is what the article said to me.
Lack of housing, poor health care, and lack of education are also all directly linked to the cost of transport. Government only has so much money and it currently costs multiple times the value of the goods to transport them to the needed locations.
Also don't point me to an article done by a fellow that visited briefly at best and doesn't actually know any of the logistics involved in doing anything at all up here. I live here, I am not from here, but I do live here. The reality is much different than the picture thats painted by most government reports.
There are a lot of social problems, but there are people working towards solving those problems. One of the largest slowdowns to progress is transport.
On education... how are you going to educate if you don't have a school that is sufficient to do it in? A piece of plywood that costs $15 to buy at home depot somewhere down south costs another $10-15 to get in here by boat, and you damn well better make sure you get enough then because if you don't you either have to fly it, and then you're looking at anywhere from $60 to $100 per sheet in freight, or you're waiting another year for the next boat.
To put that into more perspective for you: A hospital that would cost 3 million down south will cost 5 to 6 million here, IF you don't go into overruns and air freight. If anything is emergency and gets flown it it starts climbing higher.
Anything at all that starts reducing that 2-3 million extra overhead on that hospital is a huge step in the right direction. Even if its only air freight that it reduces and gets the total overrun much closer to or maybe a little below that 2 million, thats still a lot of money.
You're downplaying something that would ordinarily, down south somewhere, be fine to downplay, because honestly, it doesn't play as large a role. When you're looking at it up here, the dollar figure for it is so huge that it actually becomes central to everything.
Re:Vaccuum ships? (Score:1, Informative)
If you have read the article How Helium Balloons Work, then you know that a liter of air at sea level weighs about 1.25 grams. A liter is 1,000 cubic centimeters, or about 61 cubic inches -- the size of a 1-liter soda bottle. A liter of helium, on the other hand, weighs about 0.18 grams. If you weigh a 1-liter bottle filled with air and then weigh the same bottle filled with helium, it will weigh about 1.07 grams less. If the bottle itself weighed less than a gram, you couldn't weigh it at all -- it would float! You could turn the scale upside down and put it above the floating bottle to check its negative weight! Generally, a balloon has to be several liters in size before the 1-gram-per-liter weight difference of helium vs. air is enough to overcome the weight of the balloon itself and float.
If you could somehow fill a 1-liter bottle with a vacuum, it would float even better. A perfect vacuum weighs zero grams, so a liter of perfect vacuum weighs 0.18 grams less than a liter of helium. The problem, of course, is that building a lightweight container that can hold a vacuum is not nearly as easy as building a fabric envelope that can hold helium. The phrase Nature abhors a vacuum sums it up nicely. If you could figure out a way to do it, however, you would be set -- your vacuum balloon would float!
Note that you would not need to have a perfect vacuum. Any air that you take out of the envelope will lower the weight and cause lift.
source [howstuffworks.com]