19th Century Airship Technology for Port Security

fenimor writes "Airships - known today mainly for advertising flyovers at football games - are the core of a new coastal surveillance system in development for the the U.S. Department of Defense. These stationary platforms 25 times the size of a Goodyear blimp will be equipped with an array of cutting-edge equipment for remote sensing, communications, and risk analysis, providing surveillance coverage over a surface area of 500,000 square miles from an altitude of 70,000 feet."

Comments

Almost as good as Anatidocphobia

[ackthpt]

2005: Somewhere, somehow a blimp is watching YOU!

Currently the USCG employes a pair of blimps "Fat Albert" on Cudjoe Key to watch for dope smugglers, air traffic, etc.

Ob: SovietRussia: For Soviet Russia YOU spy on the blimp!

Duh.

[Anonymous Coward]

It really is SO obvious that they need to put some giant laserbeams on this shit.

As long as....

[IanDanforth]

I can find out where they are and have the option of not being tracked I'm ok with this. Otherwise we just have Big Brother gone lighter than air. -I

Terrorism

[Rip Van Winkle]

Sounds like a really good terrorist target to me.. In fact anyone with an air rifle could do some damage!

Re:Terrorism

[multiplexo]

Sounds like a really good terrorist target to me.. In fact anyone with an air rifle could do some damage!

If a terrorist has the know-how to build an air rifle that has a range of 14 to 16 miles then he's probably going to be going after some other targets.

I for one welcome our new blimp-borne overlords (There! I had to say it!).

Re:Terrorism

[Moraelin]

You'd be surprised what you can do with a little knowledge of physics.

Let's start designing a really good airgun. Or actually describe something which already exists.

First let's remember that you can only accelerate something via gas pressure to the speed of the gas mollecules themselves. Any faster, and the gas will literally be left behind.

So we'll want to maximize the velocity of those mollecules. The energy of one of those little buggers depends on temperature. But that's not our ticket. Our ticket is noting that at the same energy (hence temperature) the less mass you have, the more velocity is needed to achive that energy.

Hence, you'll want a very lightweight gas. Hydrogen or helium will do just nicely. So we'll build a hydrogen gas gun.

Now to compress the helium. Well, have the airgun's barrel, which is a thin tube. We'll also have a much larger tube with a piston to compress the gas.

Think: a syringe. We push the piston in the large syringe body, to shoot a tiny sting through the tubular needle. Of course, at a much larger scale.

We'll also need to push the piston really hard, to create a lot of pressure. An explosion will do that just nicely.

It's really much like a conventional gun with a twist. Instead of the (relatively) heavy gasses from the explosion directly pushing the projectile, we compress hydrogen with them and the hydrogen pushes the projectile.

It's a very large device and very much a one shot gun, because reloading it takes ages. As such fairly useless against either ground targets or aircraft. (Against aircraft you really want something which sprays a lot of bullets.)

It also accelerates a dart to miles per second velocities. Theoretically, you could shoot at a sattellite in low orbit with it, except you would need to aim very very well. However, to punch a hole through a huge stationary blimp, it's perfect.

It's also low tech. A lot lower tech than rail guns. Any third world country could build one, if they wanted to. Heck, theoretically you could build one in your back yard. (But in practice the police would want to know about all those explosives you're buying.)

Until now, well, there was no problem for which it would be a solution. Now those blimps are just the problem for it.

Will Angelina Jolie be commanding one of these

[Travoltus]

when Britain starts making 'em?

Great...

[Izago909]

So now we have even more national security data that we can't monitor in real time. What good is all this info supposed to be if we can't use it to stop a problem before it happens? Technology is great at recording, storing, and retrieving information, but I don't see a database server walking down to the beach to make an arrest. Are the politicians considering an increase in the Coast Guard, Port Authority, and other applicable agencies? If not, all this new technology won't do much good.

Re:Great...

[Scrameustache]

What good is all this info supposed to be if we can't use it to stop a problem before it happens?

Blackmail.

Are you now, or have you ever been, a member of the communist part...er... terrorist?

massive innefficiency

[samot84aol.com]

Dosn't this seem terribly innefficient? I mean, mantaining these things in the air at all times, to do a job that seems to already be done by survelience satellites, airplanes and ground. And how does this reduce the risk to terrorism?

Re:massive innefficiency

[Colin Smith]

Well, it can see further than the ground and means you can probably get rid of the AWACS planes. It's unmanned and the project is far far cheaper than a single AWACS plane.

How cruel!

[Anonymous Coward]

I, for one, will not tolerate the Bush administration tethering Michael Moore 70,000 feet above the ocean.

The possibility of an unprecedented ecological disaster is far too great. (Besides, it'll really ruin the view.) /cue Bush-bash

Sell aluminum futures!

[Tackhead]

Wow. Once these things go up, those tinfoil-hat wearing folks will be out of luck.

Sure, the tinfoil protects them from the invisible mind control lasers, but the reflected solar radiation just makes them easier to target from the air with the onboard plasma cannons.

Repairs?

[Paster Of Muppets]

Hmm... Operating at 70,000 feet? How the hell are you meant to repair them? Bringing it back down for maintenance is the only option I can think of, and that will severely reduce your observational capabilities there.

Also, what if it gets punctured or damaged while at 70,000 feet? Will there be an immediate action plan to send up a replacement? As it's unmanned, I guess this means that every little defect requires a ground-based overhaul?

Personally, I don't see it working at the moment.

Re:Repairs?

[jd]

Repairs'll be the least of their problems. At that altitude, they'll have other things on their mind. Not least, the air pressure is much lower, which will mean that the bags holding the helium will be under much greater stress. The quality of the components must be considerably higher than normal, if they plan any prolonged flights.

The radiation levels up there are also substantially higher than on the ground. Domestic air crews don't fly much about 35,000 feet, but still get enough cosmic rays and other forms of radiation for them to be very strictly regulated.

At 70,000 feet, you're talking substantially harsher conditions. This isn't a problem, for most people working at that altitude, because they're usually not up there for very long. Probably those who would be most affected would be those who flew the U2s and Blackbirds, as those would likely have involved prolonged periods at very high altitude.

It's doubtful such information has ever been released, but it would be interesting to know if the radiation exposure of such pilots has ever been measured, and/or if cancer rates associated with the sorts of radiation involved were higher than normal.

Airship patrols, though, are going to be a lot more hazardous. Aircraft might be in the air for a few hours, but airships may easily be flying around with the same crew for days or even weeks. They could easily stock enough food on board such a vessel to manage it.

A week of being blasted by high-energy radiation might easily put a person over the safety limits for exposure. Of course, the Government could do what it always does in such cases, and raise the safety limits, so that it was ok.

Re:Repairs?

[505]

No, not every little defect will require a ground based overhal. Quite the opposite. Airships are *great* for repairs.

The early 20th-century airships (I dont know about blimps) could have a lot of repairs done in flight. Crewmen could work outside the skin of the ship to patch holes in the skin, fiddle with the fins, and more.

This was especially useful on first-of-class or prototype ships. See Nevil Shute Norway's memoir Slide Rule(ISBN: 1842322915) for some amazing anecdotes about designing, building, and testing an airship.

An unmanned airship in need of manned repair could be visited by a manned airship, blimp or helicopter with a repair crew.

Most airships had some spare lift for emergencies. A ship would carry ballast for jettison when needed, and in extreme situations could jettison furniture, reserve fuel, and other material. Unless it were combined with some other problem (such as a bad storm) a ship could limp for a considerable distance while one gas-bag was deflating. In the case that one gas-bag was deflating, a modern airship might even be able to salvage some of the gas.

Some of the problems of maintaining long-term unmanned aircraft are even worse for satellites, which people keep finding ways to use.

Something new to worry about....

[Stephen Samuel]

A terrorist with a really big slingsghot.

Mr Smithers!

[Sean80]

Mr Smithers, my devious plan is to block out the sun! Release the blimps!

Re:Mr Smithers!

[MrSmithers]

Yes, sir! I'll get right on it.

Blimps are go, sir.

Finally I can sleep soundly

[Hoplite3]

Whew! Total safety is so close I can taste it! Thanks, guys. Without your cameras everywhere, we'd all be blown up tomorrow. (Well, I'm not sure the one in my bathroom is necessary, but I do store bleach there and it could be used as a weapon if terrorists break into my house.)

Pentagon Hot Air

[Doc Ruby]

These airships would be a great advance in transportation, cargo, and exploring/inhabiting greater volumes of the Earth's capacity. But how do they protect our ports from some asshole with a stick of dynamite and a scuba tank stowed away a petroleum supertanker? This money and Defense management would be much better spent infiltrating terrorists with spies, cutting their financial, political and media sponsors, and investing in democratizing the tyrannies that pressure the populations from which they recruit. Unless our goal is to keep the Pentagon fat on job corps and science budgets, some state capitalist corporate welfare for defense contractors.

Re:Pentagon Hot Air

[Anonymous Coward]

This money and Defense management would be much better spent infiltrating terrorists with spies, cutting their financial, political and media sponsors, and investing in democratizing the tyrannies that pressure the populations from which they recruit.

That sounds all well in good. But here's the reality of the situation:

1. Infiltrating terror networks with spies means that we'll be paying "bad" people with your tax dollars. In order to get in good with the terrorists, our agent will have to do some despicible acts. The fear that Congressperson X authorized paying agent Y with tax dollars to do dispicible act Z to gain the terrorists' trust will come out some day will prevent X from ever authorizing such stuff.
2. Cutting their financial, political, and media connections requires the cooperation of the rest o f the world. And, in case you haven't bee paying attention for the last two years, the rest of the world doesn't like us too much. So don't expect them to jump when we demand that they crack down on terror-related lines of communication.
3. Democratizing the world? That's quite a feat. Quite frankly, I think it's more feasible to cover the atmosphere with spy-airships then it is to convert the entire world into a democracy.

I haven't seen this mentioned...

[Epistax]

What keeps some random person who owns a gun from taking one of these down, exactly? Does the impact get distributed in such a way that it will not be hurt by conventional arms? Do keep in mind that being in American, conventional arms is a 50-caliber sniper rifle capable of going straight through body armor (of several people).

Re:I haven't seen this mentioned...

[Wyatt Earp]

Even a 50 caliber (12.7mm) or the old Russian heavy-machine gun the 14.5mm can't come close to this altitude.

http://www.globalsecurity.org/military/systems/g ro und/m2-50cal.htm

http://www.globalsecurity.org/military/systems/g ro und/m82.htm

Maximum effective range on equipment-sized targets: 1800 meters

Now, in the United States, a 50 caliber sniper rifle isn't a "conventional arm". It's a special application rifle used in the military and by a very small special core of long distance shooters.

In the United States, the most common rounds are 5.56mm and a wide variety of 7 to 8mm rounds. (.30, .300, 30.06, 7.62, 7 Magnum, and so forth)

Re:I haven't seen this mentioned...

[seanadams.com]

What keeps some random person who owns a gun from taking one of these down, exactly?

Gravity.

It has been called an "unforgiving motherfucker" by the walker-bound elderly, but the fact is, only gravity can protect our prescious airships from the terrorists who seek to destroy our way of life.

Let's suppose you've got a nice powerful 50 cal that fires at 2000 feet per second.

physics tells us that it'll take 2000 feet per second / 32 feet per second per second = 62.5 seconds to reach it's max height.

Then we can figure out how high that is with this equation:

distance = initial speed * time - ( 1/2 ) * acceleration * time^2

2000 * 62.5 - 0.5 * 32 * 62.5^2
125000 - 62500
== 62500

So your bullet will turn around roughly a mile short of the target. :)

Re:I haven't seen this mentioned...

[StyxRiver]

Could you please name some "conventional arms" that is capable of shooting nearly 14 miles in the air? Or someone who's capable of hitting a target from 14 miles away?

Re:I haven't seen this mentioned...

[seanadams.com]

oops, that's in a vacuum. :)

Re:I haven't seen this mentioned...

[horizontech10]

Surprisingly, real life is not like a Wile E. Coyote cartoon -- putting a bullet into a blimp or airship will not send it wooshing across the sky. The design in TFA is 5 million cubic feet. At a guess, if you put 100 rounds of 50-caliber ammo completely through the envelope, you'd probably have up to 24 hours before the loss of helium would force the ship to land.

Ever heard of hot spares?

[Andy Dodd]

If one starts having problems, send up a replacement THEN bring the bad one down.

No problems that wouldn't be issues with any other technique in use (satellite, helicopter, airplane, etc.)

Re:Ever heard of hot spares?

[Paster Of Muppets]

With a coverage of 500,000 square miles, that works out as a circle of radius 400miles. Given an effective range of, say, 750 miles per blimp (need some overlap at the edges at least), and that the US-Mexico border is 3,100km, you'd need 5 just for this border. What about the coastlines, or the border with Canada? To do as you suggest, you'd need at least 50% again (so that there is one covering every pair as a bare minimum), as well as as a landing & repair facility not too far away.

To reiterate my point, not feasible.

Simple

[Andy Dodd]

Conventional arms can't easily hit a target a few thousand feet above you, let alone SEVENTY thousand feet.

Even fighter jets have trouble exceeding 50-60 thousand feet IIRC. Only specialized aircraft (Scaled's White Knight is one such example) can reach these altitudes.

I'm sure they wouldn't use hydrogen

[cft_128]

I'm sure they wouldn't use hydrogen, but that still begs the question of how these will affect the worlds helium supply. Probably not that much, but from what I have read it comes from limited places (mostly Texas) and once has a tendency to escape into space once it is out of the ground. I have to imagine having lots of these large helium balloons will not help matters.

Re:I'm sure they wouldn't use hydrogen

[wass]

These airships are peanuts compared to what industry uses (cryogenics, for instance). Not just that, but remember the pressure of the atmosphere at these altitudes is so low that the giant volume of the airships would be considerably smaller at sea level. Hence, much less helium would be used than you'd expect. About 10 years ago I worked on a balloon project with NASA, and when we launched the balloon didn't even look like it had much helium at all in it, but it sure lifted off pretty fast (went about 20 miles high).

You're right that helium escapes into space, at the surface temperature of the Earth, helium atoms have escape velocity (or close enough to it, accounting for the Maxwellian velocity distribution). So unearthed helium eventually escapes away from the planet. Hydrogen does as well, but I believe all other gases are heavy enough to remain bound.

I work in cryogenics here in the USA, and we routinely let helium gas escape into the air (eg, when inserting a room-temperature insert into a dewar of liquid helium). In Europe, from what I understand, most labs collect this boiled-off helium gas, and somewhere else they can re-liquefy it. Don't know what Canada, South America, Asia, or other places do, though.

One of my professors was explaining why we don't recycle the helium here in the USA. He said this is because helium is typically 'mined' at the same time as companies dig for oil and natural gas. Thats where the large helium deposits are found. The market for helium is so small that petroleum companies want to just let the helium gas escape, it's not worth their time to collect/purify/sell it.

The NSF, however, doesn't want this to happen (environmental issues and maybe to capture more of the rare He3 too), and was able to influence American-based petrol companies to collect and sell the helium instead of wasting it. In exchange the oil companies need to have enough of a helium market to do this, so that's why Helium gas is typically not recycled in the USA, so the oil companies will sell it instead of let it go.

As one side note - you need to use alot of He gas to make recycling it cost effective, so only a few institutions in the USA recycle He. In Europe the density of such labs is much higher, so it's easier for Europeans to recycle this. Not sure if He is recycled in South America or Asia, though.

So unless my professor is entirely bullshitting, the problem stems not only from many labs not recycling He, but from global petrol companies letting the He gas free instead of capturing it themselves. But as to your original question, there shouldn't be significant amounts of helium used in the airships compared to global supply.

Not completely new

[tm2b]

In principle this isn't that new, it's an expansion upon an existing program.

For example, if you check the north Florida (Jacksonville sectional) aviation chart there's an obstacle along the west coast of the state, a border observation balloon at the "bend" between the peninsula of Florida and the pan handle. It has been used for years to monitor the Florida coast against smuggling from the Gulf of Mexico.

What looks different about this program is that the "balloons" will move at a very high altitude. It's unclear to me why stationary stations aren't sufficient for border monitoring, unless you want to monitor activity by all sorts of people in the interior of the country.

It does give them another excuse for UFO debunking though.

Airships to orbit

[cft_128]

This reminds me of JP Aerospace's plans and ideas for high altitude platforms to launch airships into orbit. Looks pretty nifty.

Cheaper Solutions

[Lev13than]

There are much cheaper alternatives in the works, such as the High Frequency Surface Wave Radar being developed by Raytheon Canada and Defence Research Development Canada.

The big problem with conventional radar is that it only works in line-of-site, but Raytheon's SWR-503 Surface Wave Radar uses high-frequency radar waves that "wrap" around the curvature of the earth. The system has been proven to detect and track aircraft, surface vessels and icebergs out to 500 km from the shore in a sector of up to 120 degrees. Suspicious objects can be investigated by satellite, surface ship, patrol aircraft or very cheaply & covertly via unmanned drone.

Canada plans to install an array of radar installations along the East Coast in order to provide a seamless picture of all maritime activity occuring in the country's economic zone. Similar research is being carried out in the US, Australia and other countries. This seems like a much more effective use of resources than a massive blimp installation

Re:Cheaper Solutions

[Ironsides]

You mention Icebergs and maritime activity. But most drug smugler boats are less than 8 feet above water at the top while most icebergs and any ships worth tracking are at least 40 feet at the top. Can the radar work with such a small profile? Also, will it work in high seas? Even normal weather in the north atlantic has at least 8 foot swells when you get out to sea. Will it still work then?

Re:Cheaper Solutions

[Lev13than]

You mention Icebergs and maritime activity. But most drug smugler boats are less than 8 feet above water at the top while most icebergs and any ships worth tracking are at least 40 feet at the top. Can the radar work with such a small profile?

Manufacturers claim it can:
- AMS says that their system can track small high-speed craft.
- Raytheon claims that it has proof-of-concept that their system can detect "go-fast boats, fishing boats, large support vessels, rigid hull inflatable boats, jet skis, as well as small, low flying aircraft and helicopters" (link).

Whether it works reliably is the big question, but then you're unlikely to encounter a RHIB at 500km offshore. One would expect conventional radar to provide additional resolution closer to shore.

Re:Cheaper Solutions

[kootsoop]

Australia has been using an over-the-horizon radar with a range of about 3000 km for a while now. See http://defence-data.com/features/fpage37.htm for info.

Re:Cheaper Solutions

[Relifram]

Small correction: The surface radars in question actually use low frequency "radar waves" (no such thing, it's radio waves). Correctly: the system uses HF RF (HF band RF) which is a considerably lower frequency band than most modern radars operate at. At a guess these HF radar systems will suffer from problems of low resolution, making them less suitable for detection of small targets than an S or X band airborne system would.

Naked Movies Of Your Neighbors, Anyone?

[DanielMarkham]

THz radiation?

It says in the article it can be adjusted to see through plastics, clothes, etc

Clothes! Isn't this the same stuff that was responsible for all the X-Ray vision claims? Do we really want sensor platforms over most all of our major cities with the ability to see through people's clothes? I mean, I'm all for having the government check up on my library habits, but this may be taking it a little too far, no?

Port security, eh?

[AaronStJ]

Port security? I thought we already had that pretty much covered, what with port knocking, firewalls, and ssh tunnelling...

Re:Weather?

[Wyatt Earp]

Weather tops out at the Tropopause, this would be above it as the Tropopause most of the time. Wikipedia has it at 6 km (4 miles) at the poles to 17 km (11 miles) at the equator.

Your big thunderheads in the Midwest "anvil" out at about 40-50,000 feet.

http://en.wikipedia.org/wiki/Tropopause

They could also be good for astronomy

[Michael Woodhams]

Astronomers have occasionally used balloon borne telescopes for getting above most of the atmosphere, as it is much cheaper than a satellite. If there is a mass-produced long duration stratespheric balloon/airship available, it could make this much more viable.

As an aside - the article also discusses "Terahertz imaging." One terahertz corresponds to wavelength of about 0.3 mm or 300 microns - extreme IR, or short sub-millimetre, depending on your point of view.

Re:Hell of an air rifle..

[macz]

The Goodyear blimp comes back with massive holes in it from every game. Everything from Rednecks with deer rifles, to bird strikes rip the hell out of it every time it goes up.

Do a blimp search at http://www.ntsb.gov/NTSB/query.asp and you can see that since 1962, there have only been 23 accidents in the US and only 2 of them have been fatal. These things are well nigh indestructible.

Re:Ground control....

[hedge_death_shootout]

I checked with them.
Apparently the planes will simply crash through the cables - diverting idea too much hassle.

Re:What about space?

[identity0]

Problem with satellites is, they move really fast relative to the ground, so it's hard to use them to track movements of people or vehicles over time. Spy satelites aren't put in geosynchronous orbit because that's really far away and it would be impossible to see stuff from that altitude.

I would guess that blimps could loiter overn an area for a really long time compared to sats. Plus, you could upgrade them over time, something you can't do with satellites.

Re:Boom!?

[Deadstick]

We had plenty of helium then too. We wouldn't sell it to Germany because they had used Zeppelins to bomb London only 20 years before.

In those days, essentially all the helium in the world came from a hole in the ground outside Amarillo, Texas. It sits atop a big deposit of alpha-emitting ores, and every alpha particle sooner or later picks up two electrons, which makes it a helium atom. Helium was a big contributor to the economic development of the Texas Panhandle, which is why Amarillo is the only city with a monument to an element.

rj

Starcraft

[Lord_Dweomer]

"Spawn more Overlords."

Sorry, had to be said.

Why?

[bleckywelcky]

You don't know all the positions of the government's satellites, why should you care about the blimps? And no, this isn't a tinfoil hat theory. Do you have any idea how many payloads are launched each year and described only as a "4000 kg to 6000 kg chunk of mass"?

Remember that satellite photo of the 9/11 ground zero area that could show vehicles and people? Think that's the best the government has ... lmao ... think again. It's amazing the things you learn when you get into defense - and then it's funny seeing people squirm about something so trivial as a blimp floating along the coast.

Re:Why?

[ckaminski]

Yes, but enough people track these things that the orbits themselves can be found, not necessarily the function (yet sometimes the function can be determined by the type of orbit).

IIRC, NORAD tracking data includes classified satellite orbits.

Or, you could read the article before posting

[serutan]

The system discussed in the article involves a fleet of airships communicating with an array of sensors installed inside cargo containers so they can scan the contents of the containers. Over-the-horizon radar may be an interesting subject, but it's not a cheap alternative way to do this and has nothing to do with the article.

And what exactly will they be able to see??

[kevlar]

At 70,000 ft, atmospheric distortion (looking down) because a huge problem. You might be able to have optics that can make out a license plate in theory, but in practice it wouldn't be possible without some seriously adaptive optics.

Re:And what exactly will they be able to see??

[aardvarkjoe]

At 70,000 ft, atmospheric distortion (looking down) because a huge problem.

You're right, of course. After all, it's not like anyone has ever found a use for cameras at or above this height before.

Re:And what exactly will they be able to see??

[Oswald]

Do you think this is the same DoD that's been flying U2s and SR71s at 70,000ft and above, taking pictures at jet-speed (in the '71's case, damn near warp speed) since the early 1960's?

Think again

[tm2b]

They'll be 10-15 miles up. That's not exactly easy to pick out of a very large sky.

Re:Boom!?

[Anonymous Coward]

The U2 was downed because the pilot (Francis Gary Powers) had to decrease altitude due to an engine problem. That brought him within range of Soviet missiles.

As for blimps, they are at approximately atmospheric pressure, so punching holes in them only damages the envelope. Gas escapes, but not at a rate fast enough to cause it to crash before repairs can be made. Latex balloons burst catastrophically when punctured because they are under tension. Since blimp envelopes are not under tension, they do not rip apart like children's balloons.

I have never heard of blimps having multiple chambers before. This is how airships work, but blimps are just balloons with propulsion.

aQazaQa

Re:Hell of an air rifle..

[ckaminski]

And it never occurred to you that there were HUMANS on board that thing? That don't react well to .30-06 rounds travelling at high velocity?

You *ARE* a redneck.

Yes, that's millimeter-wave with 500-mile range

[billstewart]

These things have roughly 500-mile range, and yes, millimeter-wave radar is the stuff that Homeland Security wanted before everybody started reminding them that Ashcroft is a prude (so they started pretending they'd use image-processing to block that usage.) If you really believe all the funding applications here, you have to wonder when they'll put up a webcam...

The "Blimp for Security" concept is already here.

[MrSnivvel]

This story is about a blimp currently in the skies above Washington D.C. What better way to have surveillance over a population than with a very quiet slow moving craft that can carry a large payload. Unmanned flying drones cost too much, travel too fast, don't have the long flight times, and have the payload capacity. Airships (or blimps) give more bang for the buck.

Re:Camera Blimps over NYC during Repub Convention

[ackthpt]

there was a camera blimp over New York City during the Republican National Convention.

I thought that was Rush Limbaugh...