Some of the Most Random Tech Questions Ever

[JMBuilder]

I have here a random assortment of basic questions to give me some insight on practicality and such.

1. Would a flying aircraft carrier be practical in any way?

2. Could the EmDrive be enhanced by including more microwave compression chambers?

3. Would a ramrocket be more efficient with an aerospike nozzle?

[WestAir]

1. Not at all, unless it were an airship. At that point, you'd be smarter to simply make it a flying missile cruiser than an aircraft carrier. And at that point, you'd just be better off with a real missile cruiser. [barring in mind that because the sea has no nationality but airspace does, ships make far better platforms than aircraft.]

[How2FoldSoup]

To answer your question about a ramjet: No. Jet engines essentially already do what aerospike nozzles do naturally...

The reason aerospikes are nice is that they use the pressure of the ambient environment to funnel the exhaust of a rocket to give the best efficiency in terms of ISP. Modern and past jet nozzles basically already do this..

See your last thread on the question for other answers...

http://forum.kerbalspaceprogram.com/threads/98812-Toroidal-Aerospike-Air-Augmented-Rocket

http://upload.wikimedia.org/wikipedia/commons/5/56/J85_ge_17a_turbojet_engine.jpg

Or, see the aerospike-like geometries on the inside of the above engine at the nozzle.

Also, you can't make a drive more effective that isn't even proven to work yet. That's like saying we should make fusion better by using "insert exotic fuels here" instead of trying to achieve a sustainable reaction first..

[Boomerang]

Unless it's been locked for testiness, there's already been a thread about the EmDrive and other such devices. I would recommend waiting for far more thorough testing about whether the thing even actually works before starting to wonder about how we can make it work better.

Edit: Warning, here be testiness:

http://forum.kerbalspaceprogram.com/threads/97806-Cannae-EmDrive

Edited November 12, 2014 by Boomerang

[Tommygun]

Flying aircraft carriers were tried by several countries back in the early 20th century.

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

The USS Akron and Macon where, I think, the most elaborate attempts. They carried five aircraft internally.

The air weather in the US is just too severe for these types of craft.

Edited November 12, 2014 by Tommygun

[magnemoe]

Flying aircraft carriers were tried by several countries back in the early 20th century.

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

The USS Akron and Macon were, I think, the most elaborate attempts. They carried five aircraft internally.

The air weather in the US is just too severe for thees types of craft.

It was also some attempt during the 50s with B36.

Problem with an flying aircraft carrier is that it has to be idiotic large, the airship idea for sea patrols during the 1930 made sense as planes had limited range but was small enough to be carried by an airship.

1950 and forward, fighter planes are so heavy it would be unpractical, more so as you can refuel in the air and have very long range anyway.

On the griping hand, it has been some talk about launching and recovering UAV from planes. This make some sense in some settings where you want low level recon without establish an base.

[Nibb31]

I have here a random assortment of basic questions to give me some insight on practicality and such.

1. Would a flying aircraft carrier be practical in any way?

2. Could the EmDrive be enhanced by including more microwave compression chambers?

3. Would a ramrocket be more efficient with an aerospike nozzle?

1. It would be huge, expensive, and vulnerable. There is no point when there are already air bases, carrier ships, drones, and inflight refueling.

2. Until proven otherwise, the EmDrive produces zero thrust. Zero multiplied by 1000 is still zero.

3. Aerospikes are not "more efficient", they have constant efficiency from sea-level to vacuum.

Edited November 12, 2014 by Nibb31

[K^2]

The cool thing about flight of any kind is that the bigger you get, the more efficient flying gets. Proportionally speaking, that is. So there is nothing theoretically wrong with the principle of a flying aircraft carrier. It'd be basically be a series of nuclear reactors driving huge fans, all paved on top with an air strip, but that's basically what you're asking for.

Would it be vulnerable? Not much more than an aircraft carrier. Between naval caliber cannons you'd be able to install on that thing, missile defense system, a full load of fighters and other support aircraft, it'd be hard to get close enough to attack it. And since a lot of its systems would be redundant, a few hits won't do it. So short of a nuclear ICBM hit, I can't imagine anyone bringing it down.

What it comes down to is cost to benefit. A nation can own at least a few supercarriers, complete with support fleets, for the cost of one of these. And a single nuke that gets past defense systems would bring it down. It's just not really worth it.

[hugix]

There are a couple of aircraft carrier aircraft, in the strictest sense of the word.

Here a couple of aircrafts carrying air/spacrcraft :

[*Aqua*]

I can't imagine anyone bringing it down.

As the US Army demonstrated, Lasers will bring down everything. Rail guns will probably work, too. Or to be more realistic: A huge amount of missles will also be able to prenetrate the defense systems. Giving how easy it will be to hit it, the strategic and tactical importance of this ship and not to mention the prestige, you can expect an enemy will fire waves after waves of missles against it.

[cicatrix]

... or a single hacker breaking in the control systems.

Really, if I emit a strong EMP on a floating carrier it will remain afloat. What will happen to an airborne carrier?

[*Aqua*]

Nothing.

You can expect it to be EMP-proof.

[K^2]

As the US Army demonstrated, Lasers will bring down everything.

Erm... I'm not sure you understand. We aren't talking about bringing down an airplane, where you have to burn through a few mm of aluminum or plastic. We are talking about burning through naval armor from range of 100 miles or more. Not only do not lasers like that not exist, it'd cost more to build one than the carrier in question, because the only way to even do this would involve an enormous particle accelerator.

Rail guns will probably work, too.

Railguns are still way outgunned on large caliber by conventional artillery. Which this thing will carry. In spades. And it will have the altitude advantage + not being a stationary target. You are not bringing this thing down with dumb projectiles. It can and will level anything capable of harming it before getting into actual range.

Or to be more realistic: A huge amount of missles will also be able to prenetrate the defense systems.

Yup. Now we are getting somewhere. You'd have to spam missiles at it.

Except aircraft carriers are also vulnerable to such an attack. Do you know when the last aircraft carrier was sunk? WWII. And that was one of the smaller carriers. A nuke still remains the only reliable way to sink a supercarrier.

... or a single hacker breaking in the control systems.

You watch too much TV. Let me put this into perspective. The control systems would only be necessary to control reactors and the turbines. Basically, this is equivalent to nuclear power plant operation. Number of nuclear power plants hacked by terrorists: 0.

Really, if I emit a strong EMP on a floating carrier it will remain afloat. What will happen to an airborne carrier?

Ditto. EMP sources like that do no exist. The only thing capable of producing enough EMP to disrupt a machine like this is a nuclear blast. Which makes question of whether it can stay afloat moot.

So we're back to having to nuke it. Which means multiple ICBM launches against a moving target. This is not an easy thing to destroy.

You're still much better off building multiple aircraft carriers with the same resources, but this is far from a useless thing. A country that has one of these would automatically be a major world power.

[dharak1]

Now that I think about it aircraft carriers are amazingly effective at what they do. If the only thing able to take one down during a war was a nuke it would be a total disaster to basically tell the public you have to nuke the ocean near their homes. Think about it, during the meltdown at Fukushima people were going crazy about the radiation and that was on the other side of the planet. If there was an aircraft carrier attacking the wast coast a few hundred Km out and the US dropped a nuke on it it would be a PR disaster. "United States poisons worlds oceans" even if the fallout was no immediate threat it would be impossible to tell people otherwise just like Fukushima.

[cicatrix]

Erm... I'm not sure you understand. We aren't talking about bringing down an airplane, where you have to burn through a few mm of aluminum or plastic. We are talking about burning through naval armor from range of 100 miles or more.

I shudder from the thought of how much weight this behemoth will carry then. Actually, I have doubts about if this thing could fly at all. Also, even if it WILL fly, the amount of power necessary to keep it flying would soon bankrupt even the most prosperous country. Not to mention that it will probably be much slower than floating ships. Add hurricanes/turbulence and simply bad weather - those things alone will make it extremely difficult to maintain a stable flight.

Railguns are still way outgunned on large caliber by conventional artillery. Which this thing will carry. In spades. And it will have the altitude advantage + not being a stationary target.

Come on - with its inertia it's pretty close to being stationary.

You are not bringing this thing down with dumb projectiles. It can and will level anything capable of harming it before getting into actual range.

Speaking of guns. If I level a main battleship caliber at that thing and fire - what means of protection besides armor can be used? I'm not really serious at this, but still it can be theoretically possible just to fire guns at it.

Except aircraft carriers are also vulnerable to such an attack. Do you know when the last aircraft carrier was sunk? WWII.

If no carriers were sunk since the WW2 it doesn't mean they can't be sunk. The reason is simple - there were not many wars involving opponents of the 'same weight' (figuratively speaking). Russians have tons of submarines designed specifically for one single purpose - sinking carrier groups. And they do not do this with nukes alone. Conventional missiles count as well.

You watch too much TV.

THIS! Coming from a man who seriously (well, almost) proposes to build airborne aircraft carriers!

Let me put this into perspective. The control systems would only be necessary to control reactors and the turbines. Basically, this is equivalent to nuclear power plant operation. Number of nuclear power plants hacked by terrorists: 0.

Again, if nobody has ever done it before doesn't mean nobody would.

Ditto. EMP sources like that do no exist. The only thing capable of producing enough EMP to disrupt a machine like this is a nuclear blast. Which makes question of whether it can stay afloat moot.

I can arrange a nuclear blast not in the immediate vicinity of the carrier. The EMP will still hit it. Among other measures - I can jam the comms and make it blind.

P.S. I would prefer several flying fuel depots that can refuel ordinary strike aircraft (if you need more range). This way I would not be putting all of the eggs in a single basket. Our planet is rather small. A supersonic bomber can cover half of it in a matter of a few hours, fire missiles from a safe distance and fly home. No need to complicate simple things.

[KerikBalm]

Umm, K^2, I've got ti disagree with you.

Scaling up aircraft gets more efficient to a point, as you have less parasitic drag per unit mass (assuming similar densities). However, the mass of the required structure will increase dramatically. Its somewhat related to why if you scaled up an Ant, it would collapse under its own weight - unless you distribute the weight, and its like a flimsy constellation of a bunch of smaller planes joined together.

The efficiency gains (if any) would not allow you to put heavy armor plate on it, and it would be very easy to bring down. Its low maneuvarbility means you could have a KE impactor released early one, which would be difficult to destroy or sufficiently deflect.

That no carrier has been sunk since WWII is not because carriers are so hard to sink, but because there has been no large scale naval conflict since WWII.

Most analysts agree carriers are rather stupid today, and are incredibly vulnerable to missiles and subs.

[K^2]

You are thinking of cube/square problem. Which would be a factor if you tried to build conventional lift by moving this thing through the air. But you don't. All you really need to do is move air over its top surface. Given the huge size, you get almost no drag. You can basically maintain a low pressure system above the craft, and using it to support the weight. There is seriously a break-even point to this, where it gets easier to fly if you are bigger.

Well, vulnerability to subs is definitely out of the question here. And missiles really have to be coming in in huge numbers. Modern automated missile defense systems are absurdly good at protecting carriers. Again, I'm not saying it can't be brought down with enough fire power. Just that you are greatly underestimating the amount needed.

There's a reason why US navy practically consists of carrier groups.

Come on - with its inertia it's pretty close to being stationary.

With its inertia it won't maneuver well. It can still travel at airliner speeds. Even if it doesn't accelerate, hitting something going at Mach .8 isn't the same thing as hitting stationary ground targets.

Speaking of guns. If I level a main battleship caliber at that thing and fire - what means of protection besides armor can be used?

Offence is the best defense in this case. Besides armor, it has a considerable range advantage on your ground guns, which it will use to level anything that threatens it before getting into range.

In most cases, you will be limited to missiles as the only thing that can hit it, and you'd need to overwhelm its defense systems with quantity and speed of incoming missiles. That means either a huge amount of conventional missiles, or a good number of ICBM warheads.

Edited November 13, 2014 by K^2

[*Aqua*]

[...]

Again, I'm not saying it can't be brought down with enough fire power. Just that you are greatly underestimating the amount needed.

[...]

In most cases, you will be limited to missiles as the only thing that can hit it, and you'd need to overwhelm its defense systems with quantity and speed of incoming missiles. That means either a huge amount of conventional missiles, or a good number of ICBM warheads.

With waves of missles I meant waves consiting of 50-100 missles, which isn't much for non-third world countries. That amount should be enough to overwhelm defenses and guard crafts.

Of course you can always drop an ICBM on it or in the vicinity. But nobody will do that as it can trigger WW3.

[K^2]

Modern supercarrier missile defense system consists of a dozen or more anti-aircraft autocannons linked to a central control system and set to automatically track and fire on anything moving towards it. They are actually designed to be capable to take out a maneuvering ICBM warhead on reentry. It's not 100% reliable against these, of course, but one nuke isn't going to cut it. You need multiple ICBM strikes. There is no such thing as a vicinity, either. You'll need a hit well within 1km to bring something like this down, so you basically have to aim for the target, and not some abstract "vicinity". You have a minor advantage that you con't have to score a direct hit with a nuke, unlike kinetic ICBMs, but you still have to be firing well within range of the defense systems.

As for overwhelming it with cruise missiles, you have to keep in mind that the system won't need more than a few seconds to deal with each missile, and it can track and target a number of them independently. Yeah, you'll probably score some hits with a volley of 100 or so, but unless these are all tactical nukes, one hit won't bring it down. Nor will a few hits. You will need dozens of hits on critical systems, potentially into hundreds in all, and only a few percent of your missiles will be getting through. You do the math.

If you do go with tactical nukes on your missiles, a lucky hit might bring it down right away. More realistically you'll need a couple to a few. And again, we are talking about something on the order of hundred tactical strikes attempted to achieve it.

All of these are options. All of these are achievable, and way cheaper than it was to build the thing in the first place. But it is still an enormous effort that very few countries are actually capable of.

Like I said before, I don't think something like this would ever be cost effective. You can lead multiple wars in multiple countries for a fraction of a cost. But it is viable, in principle.

[cicatrix]

You are thinking of cube/square problem. Which would be a factor if you tried to build conventional lift by moving this thing through the air. But you don't. All you really need to do is move air over its top surface. Given the huge size, you get almost no drag. You can basically maintain a low pressure system above the craft, and using it to support the weight. There is seriously a break-even point to this, where it gets easier to fly if you are bigger.

I'm yet to see a practical idea about how to implement all this.

Well, vulnerability to subs is definitely out of the question here.

Why? Subs still launch missiles. Even from underwater.

Modern automated missile defense systems are absurdly good at protecting carriers.

They are, if they can acquire its targets fast enough. Modern anti-ship missiles travel at 3-5M carrying up to 1000 kg of explosives. And they maneuver in flight. How much AA turrets do you need? You'll need to defend from all directions - a sphere. 1 turret can hit 1 high speed missile at a time with 50/50 success. And you're wrong against anti-ICBM defence. It is EXTREMELY difficult to hit a target on re-entry. You'll need an interceptor missile and quite a bit of luck.

There's a reason why US navy practically consists of carrier groups.

The whole reason is to protect the carrier. That's why the groups exist in the first place. A whole bunch of ships are protecting the carrier. And US needs carriers in order to transport the battle force within the range of strike aircraft.

With its inertia it won't maneuver well. It can still travel at airliner speeds. Even if it doesn't accelerate, hitting something going at Mach .8 isn't the same thing as hitting stationary ground targets.

Hitting something that's going at Mach .8 that doesn't maneuver well is simple enough even for a student. Since it cannot evade well, its trajectory if fairly predictable.

Offence is the best defense in this case. Besides armor, it has a considerable range advantage on your ground guns, which it will use to level anything that threatens it before getting into range.

Granted, but someone might still get lucky.

In most cases, you will be limited to missiles as the only thing that can hit it, and you'd need to overwhelm its defense systems with quantity and speed of incoming missiles. That means either a huge amount of conventional missiles, or a good number of ICBM warheads.

Well, as it's been said - missiles will do well.

EDIT: P.S. Building something like this automatically makes it a perfect big slow and very desiraable target. No matter what - it will be brought down thus crippling the fighting capability of the owner by half at least. A thousand wasps are more dangerous than one big lion. And wasps eat less.

Edited November 13, 2014 by cicatrix

[Error404brain]

With waves of missles I meant waves consiting of 50-100 missles, which isn't much for non-third world countries. That amount should be enough to overwhelm defenses and guard crafts.

Of course you can always drop an ICBM on it or in the vicinity. But nobody will do that as it can trigger WW3.

If you begin to destroy an aircraft carrier, you are probably already in WW3. I mean, why would someone even try to do so if it isn't for a giant war between two superpower ?

[Sky_walker]

AMS/CIWS systems are not even nearly as good as you imagine.

To begin with - they never were tested in a real conflict against several foreign-made missiles (which, by the way, can be fired from a single fighter) and/or different types of missiles.

Secondly - regular CIWS systems used on carriers (Eg. Phalax on Nimitz) can target only a certain range of missiles (things like speed and trajectory play a huge role here - hence noone knows how Phalax would behave against real attack using, say, 4 Russian-made missiles fired from a single fighter) at certain range, average expected kill distance being 500meters doesn't give you much of a chance for mistakes. Add to this a fact that none of NATO CIWS were ever tested against Russian or Chinese supersonic cruise missiles - which is what most likely would be used against that carrier.

Third - you don't need nuclear missiles to take down a super carrier. There are many alternatives, including large calibre artillery fire, thermobaric bombs, heavy bombs (assuming you can deliver them over target, which is highly unlikely).

Fourth, the most important point: CIWS isn't always turned on. If I'd making bets how that stupid idea of flying mega-carrier would be destroyed, it's precisely that: Surprise attack (I'm pretty sure Russians would "accidentally" happen to "loose" one of their launchers to some random "insurgents" if US would push them too far). Which is only made easier by the fact that flying-mega-carrier won't have huge escorts like real, sea-borne carriers do.

In either case though - this whole topic sounds like someone seen Avengers one too many times.

Edited November 13, 2014 by Sky_walker

[*Aqua*]

There is no such thing as a vicinity, either. You'll need a hit well within 1km to bring something like this down, so you basically have to aim for the target, and not some abstract "vicinity". You have a minor advantage that you con't have to score a direct hit with a nuke, unlike kinetic ICBMs, but you still have to be firing well within range of the defense systems.

There is no vicinity? Are you sure?

The shock wave of a nuclear explosion should be strong enough to simply knock the ship out of the sky, even at ranges beyond 1 km.

Will automated defense Systems even target a missle which is "missing" its target a few kilometers to the left or right?

You will need dozens of hits on critical systems, potentially into hundreds in all, and only a few percent of your missiles will be getting through.

IMO it depends on how the ship is constructed. If it has, say, 8 propellers or jet engines and you hit 2 of them on one side. The crew/flight computer will have to shut down 2 on the other side so it won't flip over. Out of 8 you'll now only have 4 engines left. Will these be enough to keep the ship in the air? At least plane will have to do an immediate emergency landing when losing 50% of their engines.

If you do go with tactical nukes on your missiles, a lucky hit might bring it down right away.

How big do you think a flying aircraft carrier will? I guess about 200-300 meters. The smallest tactical nuke weights 0,3 kT. It will cook half of the ship and probably vaporizing a quarter of it. At least!

All of these are options. All of these are achievable, and way cheaper than it was to build the thing in the first place. But it is still an enormous effort that very few countries are actually capable of.

True.

I'm still not sure if it's a good idea to build such a thing. It will need a lot of maintenance, because it's a complex maschine. That makes it expensive, too. You'll need planes to supply it in a war (ground might be too unsafe, not flat enough to land on or not stable enough to bear the weight).

All that for what gain? Ok, it's mobile but you can also turn highway strips into airbases. That's way cheaper and if it's bombed you'll move to the next highway strip.

Like I said before, I don't think something like this would ever be cost effective. You can lead multiple wars in multiple countries for a fraction of a cost. But it is viable, in principle.

Edited November 13, 2014 by *Aqua*

[magnemoe]

AMS/CIWS systems are not even nearly as good as you imagine.

To begin with - they never were tested in a real conflict against several foreign-made missiles (which, by the way, can be fired from a single fighter) and/or different types of missiles.

Secondly - regular CIWS systems used on carriers (Eg. Phalax on Nimitz) can target only a certain range of missiles (things like speed and trajectory play a huge role here - hence noone knows how Phalax would behave against real attack using, say, 4 Russian-made missiles fired from a single fighter) at certain range, average expected kill distance being 500meters doesn't give you much of a chance for mistakes. Add to this a fact that none of NATO CIWS were ever tested against Russian or Chinese supersonic cruise missiles - which is what most likely would be used against that carrier.

Third - you don't need nuclear missiles to take down a super carrier. There are many alternatives, including large calibre artillery fire, thermobaric bombs, heavy bombs (assuming you can deliver them over target, which is highly unlikely).

Fourth, the most important point: CIWS isn't always turned on. If I'd making bets how that stupid idea of flying mega-carrier would be destroyed, it's precisely that: Surprise attack (I'm pretty sure Russians would "accidentally" happen to "loose" one of their launchers to some random "insurgents" if US would push them too far). Which is only made easier by the fact that flying-mega-carrier won't have huge escorts like real, sea-borne carriers do.

In either case though - this whole topic sounds like someone seen Avengers one too many times.

CIWS system are secondary/ tertiary line of defense, outer is the air screen who keep other planes off, second is the missiles of the air defense ships in the carrier group, if something get past this CIWS goes into action.

This give the carrier an advantage, both the size and that you want to keep your own planes out of range demands large missiles who require large carrier planes.

Something flying will not have this benefit, if its a helicopter it will not fly in the stratosphere, has problem in Afghanistan because of the attitude.

medium level truck mounted anti air missiles would be able to reach it giving short engagement times. its pretty easy to hide an truck.

Something far cheaper would be an rapid deployable airbase for VTOL and helicopters using an cargo carrying airship.

Yes the airship would be more vulnerable but it would just move in, hover some hours and move out a couple of times.

[Sky_walker]

This give the carrier an advantage, both the size and that you want to keep your own planes out of range demands large missiles who require large carrier planes.

Something flying will not have this benefit, if its a helicopter it will not fly in the stratosphere, has problem in Afghanistan because of the attitude.

medium level truck mounted anti air missiles would be able to reach it giving short engagement times. its pretty easy to hide an truck.

Something far cheaper would be an rapid deployable airbase for VTOL and helicopters using an cargo carrying airship.

Yes the airship would be more vulnerable but it would just move in, hover some hours and move out a couple of times.

Yep. Exactly. And "far cheaper" in this case is an understatement - it'd be immensely cheaper, quicker, and perhaps most importantly: it'd be safer.