250-Foot Hybrid Airship To Spy Over Afghanistan

Toe, The writes "Gizmodo details the Long Endurance Multi-intelligence Vehicle (LEMV) (based on the P-791), a spyship from US Army's Space and Missile Defense Command capable of hovering at 20,000 feet. Planned for deployment in Afghanistan, the ship can float for three weeks and carry well over a ton of payload, apparently surveillance equipment. The video on Gizmodo of the P-791 shows that these ships are a hybrid not only of both buoyancy and propulsive lift, but also of both awe and hilarity."

Protection?

[Anonymous Coward]

I read TFA and the wikipedia entry for the P-791 but I can't seem to find any actual details on the crafts construction. Specifically, what material the outer skin is made of. Seems like this kind of airship would be extremely vulnerable flying over hostile territory.

Darpa Project Vulture

[Anonymous Coward]

"DARPA's goals for Vulture are not trivial: 5 years on station with a 450kg/ 1,000lb payload, 5kW of onboard power, and sufficient loiter speed to stay on station for 99% of the time against winds encountered at 60,000-90,000 feet."

http://www.defenseindustrydaily.com/DARPAs-Vulture-What-Goes-Up-Neednt-Come-Down-04852/ [defenseindustrydaily.com]

Re:Protection?

[BrokenHalo]

Seems like this kind of airship would be extremely vulnerable flying over hostile territory.

Exactly. I'm not exactly sure what weaponry would be able to hit a target at 20,000 feet but it's a big, slow-moving target.

On the other hand, I love the whole idea of gasbags as a means of transport, and would really like to see them come back for civilian use. I can see their time coming again as fuel bills rise or the carbon emissions of winged craft become too scary.

Airships got a bad rap as a result of some messy crashes, but by of perspective, even with the Hindenburg crash [wikipedia.org] 63% of the passengers survived. Whereas if you're in a plane when it crashes, you can usually guarantee that you're toast.

A really good idea, except for that one thing...

[catmandi]

This kind of airship will, once at operating altitude, be essentially be impossible to shoot down unless the enemy has a true SAM based defense (e.g. SA-11). SAM would have no problems locking on, as they tend to be driven by an active radar on the ground - I doubt you could hide something that big from radar in any useful way (although, I wonder if making it extra radar reflective might not actually work better since it would give the missile to large an area to aim for?). Stingers have a useful ceiling of around 15,000 feet, and they're driven by infra-red, which means you probably wouldn't get a lock on.* The only other thing that would work would be a proper flak gun at around 88mm. While there's a lot of those lying around Afghanistan, getting them in working order, manning them, and providing reliable ammo would all be very problematic. Remember that flak is only really useful if someone is manning it 24/7 - the ceiling might be enough, but the range is terrible. * Of course, the problem with all this is that given the MOUNTAINS in Afghanistan, I wonder if there isn't a shoulder fired active radar missile available. The ceiling wouldn't have to be 20,000 feet, but rather 20,000 feet - the height of the mountain the defender is standing on. Also, it looks gay.

Re:Sitting duck

[mike2R]

So how long does it take to plant a roadside bomb? 15 minutes? Suppose you see some truck stop by the side of the road, some guys get out and they're doing something that might, or might not, be digging a hole. It just so happens that you've got a predator drone in the air so you blow them up five minutes later.

You would kill a lot of innocents with that policy, and ultimately lose any political support we may still have. But maybe if you know that area is suspicious, and you have a convoy going through that area you can warn them to be even more careful of that spot. More, if you had blanket coverage of large areas of Afghanistan, maybe commanders wanting to navigate a route could go back through the last days/weeks/months of surveillance and look for anything suspicious.

I dunno, I'm no soldier, but I have been trying to keep informed on Afghanistan. I've seen talk about a massive increase in surveillance as a tool against roadside bombs. The only arguments I've seen against it have been along the lines of; can't do it, it would cost to much.

Maybe it isn't practical for other reasons (I've certainly no knowledge that this blimp is actually intended for this role), but we are taking a terrible amount of casualties from bombs; both deaths and horrific injuries. I hope something can be done about it and as a (British) taxpayer I am certainly willing to pay for it.

Re:Airships are meant to be elegant.

[moosesocks]

The spire of the Empire State Building in NYC originally contained an airship docking port on the 102nd floor.

Although this idea sounds awesome [wordpress.com] in theory, it was incredibly dangerous in practice, and no airships ever managed to safely dock with the building due to severe winds and updrafts.

The idea was eventually scrapped, and the spire was converted for use as a transmission aerial, which is still in operation today. The building still retains several peculiarities relating to the unused airship terminal.

Coincidentally, a few years later the building would later survive a direct hit from a B-25 relatively unscathed. The idea of a rooftop air terminal was later resurrected with the construction of a helipad on top of the nearby Pan-Am building, which also proved to be extremely dangerous, and was permanently closed after an accident in the 1970s.

Re:Can be taken down

[Alcari]

That makes no sense... Getting up there isn't all that hard, but as it happens, there's a lot of sky that doesn't contain airships. Getting up there with a payload and a guidance system that will actually lock on to the blimp is the hard part. An AIM-92 Stinger missile has only a range of 8km, (which I assume means distance, not height) against stationary targets. That's about the best you can do for shoulder launched weapons. If you want to hit that blimp, you're going to need a really big missile. Think several meters long, a thousand kilograms, tens to hundreds of thousands of dollars, specialized launchers, etc. etc. Nothing to hard to get for a real army, but not something your average goatherd with a rifle is likely to have.

Re:Can be taken down

[sarlos]

The problem isn't necessarily reaching an altitude of 20,000 feet. A commercial airliner routinely flies over 30,000 feet high. If this is in their airspace and they can detect/find it, you can be sure they'll find a way to get to the altitude. The problem comes in when you actually try to hit it. As others have pointed out, this thing most likely has a very tiny radar signature, meaning you need good resolution radar to detect and lock onto it. Once you've overcome the challenge of finding and locking onto it, you have to overcome any countermeasure systems this is sure to be loaded with. Then you actually have to hit it. A fire-and-forget method, such as the boys did with their space camera, would have virtually no chance of hitting something at 20,000 feet. It's a very, very big sky and an airship like this isn't simply sitting stationary, it'll be flying a station keeping pattern which will probably be varied to prevent its route from being too predictable.

Re:Protection?

[smellsofbikes]

If you build a dirigible, with some structural solidity, there's no reason you can't stick jets on it and drive it very considerably faster than a blimp. You can design it very nearly aerodynamically perfect, after all: no wings, less commercial constraints to build a long cylinder. Instead it can be a teardrop 5x as long as wide, and have something very close to ideal, so you're just fighting (very considerable) skin friction, but don't have any induced drag or nearly any interference drag.

I'm not saying it's economically feasible, but I think it's technically feasible.

Well I for one would welcome them

[Moraelin]

I don't know, after my experiences with flying in an airplane, I think I'd actually pay good money for a blimp ride instead... assuming that I actually get _some_ leg space on a blimp, I could live with it taking an hour longer in flight. Quite happily.

Plus, honestly, have you flown in the last 10 years or so? Between having to come an hour early just to make it through the byzantine controls and bureaucracy in time, and stuff like having to wait almost an hour on the runway because someone forgot to also load the luggage (for bonus points: it once happened in _both_ directions)... if an airship line can simplify that and maintain, say, a 200 km/h speed in a straight line, it might actually be faster on the whole. Well, for short to medium distance flights, anyway.

Re:Yeah right

[zach_the_lizard]

The US also happens to have harbored terrorists inside its borders. Luis Posada Carilles bombed a Cuban airliner, and so far as I know, he still lives in the US, and he cannot be deported. Since we will not hand him over, Cuba has the right to invade our country and, in the process, kill thousands of innocents who have no connection to the government (intentional or not). Then, after the invasion, the Cuban government

Gas to use?

[Well-Fed Troll]

There actually is a third option: Steam From an article on that site: "As seen from the Table, this is about 60% of the lift of helium and more than twice the lift of hot air."

Wups, missing link

[Well-Fed Troll]

Argh Link didn't post: http://www.flyingkettle.com/ [flyingkettle.com]

Re:Protection?

[omega_dk]

I wouldn't go so far as to say that materials that actually do get destroyed in their use haven't the ability to become scarce, but Helium by it's very nature is non-reactive, meaning that when we 'lose' helium, we're merely displacing it, meaning it can be recovered. Once we start fusing it, I will admit it may become a scarce resource, but the world as of right now has (through human usage) exactly as many (or at least, humans have used a statistically immeasurable amount of) Helium atoms as it ever has, which cannot be said for, say, molecules of oil, which have been transformed from a long hydrocarbon chain into several other forms, notably carbon mon- and dioxide, water, and various forms economically useful (I'm looking at you, plastic!).

Anyways, I haven't read Julian Simon's theories in their entirety, but I can tell you right now he's a moron. Energy is certainly not infinite - there is an upper limit of the amount of energy that could be absorbed by a 100% efficient solar cell with the exact cross section of the earth over 5 billion years in this orbit. Infinity is factually greater than that amount.