Space Combat Techniques Discussion

[Eagle1Division]

A large and complex facility could also move the Earth...

If you gave me a long enough lever...

I meant facility or complex, not a complex facility.

I wouldn't discount high acceleration capability. It is just extremely difficult, not impossible. For example nuclear pulse propulsion is promising- Daedalus is an example of a high-rate pulse ship that achieves a pretty good thrust/mass and a high exhaust velocity. It has a gigantic engine bell, but seemingly no heat radiators, which is pretty odd for such a powerful spacecraft. Something tells me that something is going on within the Daedalus design that is either (a) wrong, or (b) very interesting. Considering that Daedalus was designed by people far smarter than me, I'm tending towards the latter...

Maybe the heat was carried way in the exhaust? Maybe it didn't contact the bell walls long enough to transfer too much heat... Look at SpaceX's Merlin Vacuum engine for the second stage of the Falcon 9. On the Falcon 9 launch video you can see the nozzle glow bright red. Maybe Daedalus does the same thing and uses the bell as a radiator, with what little heat transfers. Because while a higher exhaust velocity means more thrust power, it may also mean less contact time with chamber walls, and thus less transfer of heat...

If I had to guess.

What most highschoolers are thinking about? Sex. :lol:

I can certainly relate. What with all the Delta-V requirements and mass ratios and exhaust velocities and moon-masses and equations...

What do I do for a hobby? Why, I design spaceships.

I never say that to anyone though. They'd probably think I'm crazy. Maybe that's because I am.

It's more sane than stamp collecting, IMO. xD

So, let's do a little review on space combat before I dive into designing a combat vessel...

"A" means Aerial in military, so we'll use "E" for "aErospace".

ETG Lasers: IR? I know IR passes through atmospheres well, but does it pass through better than microwaves?
Also used to engage aircraft and secure air supremecy.

ETE Lasers: Microwave or UV?.
Lower wavelengths interacts best (so most heat on target), lowest wavelengths means less divergence. [ame="http://en.wikipedia.org/wiki/Beam_divergence"]Beam divergence - Wikipedia, the free encyclopedia[/ame]



Lasers: Effective at short ranges, useful as a PDS and only against other spacecraft at medium-short range.

Missiles?: Effective at much father range than lasers. May be used to try and swarm enemy PDS defense.
Warheads:
Nuclear FlaK
Nuclear one-shot Laser
(We put this on a rocket booster to get as close to the enemy ship as possible before firing it)


Laser combat:

"Far" range, adds heat, attempts to overheat enemy vessel. Heat imparted on enemy vessel greater than heat on own vessel due to waste heat from laser.

(Anything under "far" attack range will want a smaller cross-section. A smaller cross section means less of the laser's heat hits it, so the "far" range is farther away for the enemy)

"Near" range, close enough that the energy per square unit of area is high enough to melt or vaporize a layer of the enemy vessel's surface, causing either structural destruction (by melting) or explosive decompression (by vaporizing) a portion of the enemy vessel.


kinetic Defense:

A whipple shield on front defends from both FlaK and lasers.

Laser/Heat defense:

The whipple shield is built from an outer layer of RCC, which is reinforced and backed by a mesh of a material better suited to withstand kinetic impacts (Titanium?), which is supported by bars of the same material. Coated on top of both layers, facing the enemy vessel, is an extremely reflective material on the Microwave spectrum. (Possible?)

The RCC layer acts as a shadow shield for the vessel, and radiates as much heat as possible, and has an extremely high melting point.

In-between it and the Titanium bars and mesh is a small layer of insulation so that the Titanium isn't heated along with the RCC. The mesh allows some radiation of heat by the RCC on both sides.

The Titanium mesh secures/anchors the RCC, so it doesn't fragment and chip off, since RCC is brittle.

The titanium bars support the titanium mesh.


Finally, the vessel will have the least amount of head-on cross section possible, so that enemy "far" range will be the closest possible, and the least heat is received from enemy laser attack. Also less cross-section means a lower-mass whipple/shadow shield (WSS).


Missile Design:

The missiles will have a tiny forward cross-section, just like atmospheric ones, to minimize area exposed to laser attack. On top of the payload is a WSS (Whipple/Shadow Shield), behind it a payload terminal guidance stage, behind that a solid boost stage, and behind that the primary booster.

The Primary booster is expended before reaching enemy "far" attack range, though it still needs a small-ish cross section so that enemy "far" attack range isn't closer. Staged fuel tanks increase the Delta-Vee, along with a significant mass ratio. It's fuelled by CH4/LOX. The primary booster puts the missile on course for the enemy vessel. The engine nozzle is cheap and ablative.

The "boost" stage is a solid rocket for high thrust, high-delta-vee acceleration towards the target, to minimize interception time possible by the enemy.

Third/terminal stage is liquid MMH/N204 for precise control and correction of movement and terminal guidance.

Finally, for the greatest PDS penetration, it could carry multiple warheads.

EDIT: For most effectiveness against enemy vessels, the warheads could try to pass by the whipple shield so they have clear line of sight on the enemy vessel. Better yet, multiple warheads could approach from opposite sides, to "flank" the enemy vessel from both sides, to get behind that whipple shield. Of course this means getting very close, though...

 

[T.Neo]

I meant facility or complex, not a complex facility.

I know. I said complex facilities.

Large facilities, or complexes, are usually pretty complex just by their nature.

Maybe the heat was carried way in the exhaust? Maybe it didn't contact the bell walls long enough to transfer too much heat... Look at SpaceX's Merlin Vacuum engine for the second stage of the Falcon 9. On the Falcon 9 launch video you can see the nozzle glow bright red. Maybe Daedalus does the same thing and uses the bell as a radiator, with what little heat transfers. Because while a higher exhaust velocity means more thrust power, it may also mean less contact time with chamber walls, and thus less transfer of heat...

Some heat is carried away in the exhaust. Some is not.

Maybe the nozzle is the radiator... but... it is subject to the same physical laws, obviously. And if it gets too hot, it will melt/vaporise/disentegrate.

"A" means Aerial in military, so we'll use "E" for "aErospace".

Exoatmospheric would be a better term, I think.

Lasers: Effective at short ranges, useful as a PDS and only against other spacecraft at medium-short range.

Missiles?: Effective at much father range than lasers. May be used to try and swarm enemy PDS defense.
Warheads:
Nuclear FlaK
Nuclear one-shot Laser
(We put this on a rocket booster to get as close to the enemy ship as possible before firing it)

I wouldn't be so sure of that. The problems with lasers are beam dispersion and targeting- but they'll get to the target faster than a missile. It takes quite an amount of time to send a missile over a megameter, say, even if it is travelling at several km/s.

"Far" range, adds heat, attempts to overheat enemy vessel. Heat imparted on enemy vessel greater than heat on own vessel due to waste heat from laser.

(Anything under "far" attack range will want a smaller cross-section. A smaller cross section means less of the laser's heat hits it, so the "far" range is farther away for the enemy)

"Near" range, close enough that the energy per square unit of area is high enough to melt or vaporize a layer of the enemy vessel's surface, causing either structural destruction (by melting) or explosive decompression (by vaporizing) a portion of the enemy vessel.

If you're trying to overheat an enemy vessel, you probably won't be very effective at killing them- it could take quite a long time, during which they could dump material overboard to remove heat (they could even use propellant if they were desperate).

kinetic Defense:

A whipple shield on front defends from both FlaK and lasers.

Laser/Heat defense:

The whipple shield is built from an outer layer of RCC, which is reinforced and backed by a mesh of a material better suited to withstand kinetic impacts (Titanium?), which is supported by bars of the same material. Coated on top of both layers, facing the enemy vessel, is an extremely reflective material on the Microwave spectrum. (Possible?)

The RCC layer acts as a shadow shield for the vessel, and radiates as much heat as possible, and has an extremely high melting point.

In-between it and the Titanium bars and mesh is a small layer of insulation so that the Titanium isn't heated along with the RCC. The mesh allows some radiation of heat by the RCC on both sides.

The Titanium mesh secures/anchors the RCC, so it doesn't fragment and chip off, since RCC is brittle.

The titanium bars support the titanium mesh.


Finally, the vessel will have the least amount of head-on cross section possible, so that enemy "far" range will be the closest possible, and the least heat is received from enemy laser attack. Also less cross-section means a lower-mass whipple/shadow shield (WSS).

I don't know. I think your system is ungainly and expensive, and of dubious effectiveness.

I suggest having a strong hull, as well as potentially layers of material that is difficult to ablate.

Maybe a solution, would be pellets or flakes of graphite, potentially coated in reflective material such as titanium dioxide, as a laser defence.

You don't need any special titanium or whatnot for a whipple shield. I think you could have pretty much anything as your whipple shield layers- even a thin sheet of fabric.

It if is enough to break up the impactor into something the further shields/hull can contain, it is enough to work.

Missile Design:

The missiles will have a tiny forward cross-section, just like atmospheric ones, to minimize area exposed to laser attack. On top of the payload is a WSS (Whipple/Shadow Shield), behind it a payload terminal guidance stage, behind that a solid boost stage, and behind that the primary booster.

The Primary booster is expended before reaching enemy "far" attack range, though it still needs a small-ish cross section so that enemy "far" attack range isn't closer. Staged fuel tanks increase the Delta-Vee, along with a significant mass ratio. It's fuelled by CH4/LOX. The primary booster puts the missile on course for the enemy vessel. The engine nozzle is cheap and ablative.

The "boost" stage is a solid rocket for high thrust, high-delta-vee acceleration towards the target, to minimize interception time possible by the enemy.

Third/terminal stage is liquid MMH/N204 for precise control and correction of movement and terminal guidance.

Finally, for the greatest PDS penetration, it could carry multiple warheads.

EDIT: For most effectiveness against enemy vessels, the warheads could try to pass by the whipple shield so they have clear line of sight on the enemy vessel. Better yet, multiple warheads could approach from opposite sides, to "flank" the enemy vessel from both sides, to get behind that whipple shield. Of course this means getting very close, though...

I suggest all-liquid, all-storable. To get considerable dV, solids are at a penalty. Hypergolics are the first choice, but they're toxic, corrosive, and expensive. CH4 and LOX might be a good combination... you would only fuel them up before a battle, obviously.

You could also try a LOX/aluminium hybrid rocket. You'd probably need some sort of polymer binder to contain the powdered aluminium though.

EDIT: For most effectiveness against enemy vessels, the warheads could try to pass by the whipple shield so they have clear line of sight on the enemy vessel. Better yet, multiple warheads could approach from opposite sides, to "flank" the enemy vessel from both sides, to get behind that whipple shield. Of course this means getting very close, though...

You're assuming that only one part of the vehicle is shielded. Now this would be advantageous, but attacking from the side presents some other problems, such as changing direction in time, and potential side-shielding.

I think front-only shielding would make more sense if employed against laser attack.

 

[Eagle1Division]

Okay, I'm gonna quote out-of-order here in order to answer points in a better way, so I don't explain the same thing twice about my design...

I don't know. I think your system is ungainly and expensive, and of dubious effectiveness.

I suggest having a strong hull, as well as potentially layers of material that is difficult to ablate.

Maybe a solution, would be pellets or flakes of graphite, potentially coated in reflective material such as titanium dioxide, as a laser defence.

You don't need any special titanium or whatnot for a whipple shield. I think you could have pretty much anything as your whipple shield layers- even a thin sheet of fabric.

It if is enough to break up the impactor into something the further shields/hull can contain, it is enough to work.

You're assuming that only one part of the vehicle is shielded. Now this would be advantageous, but attacking from the side presents some other problems, such as changing direction in time, and potential side-shielding.

I think front-only shielding would make more sense if employed against laser attack.

Okay, the WSS (Whipple Shadow Shield) is "ungainly and expensive, and of dubious effectiveness", when employed as a whipple shield (well, not really, but I'll get back to that). But the key, is that it is employed against laser attack. It's a single object that serves both purposes.

It's a RCC shield that sits a large distance from the habitat module. I'll add: Behind it are 4 large radiator arrays. It's a thermal heat shield, to protect against laser attack. However, by it's very nature, being a shield of material a long distance from the habitat module, it serves somewhat as a whipple shield. Were it not for the titanium mesh, sections of it would easily chip off and it would be torn to pieces by even a small impact, like a wafer-thin ceramic plate. But the titanium mesh keeps it together in spite of minor kinetic impacts.

By having it as a shadow shield, you're also blocking line-of-sight on the enemy vessel, so it's already in position to serve as a whipple shield from enemy Nuclear-FlaK warheads. And unless you're flanked, your enemy will have to fully vaporize it before they can even start hitting your other vessel systems. And RCC can take a lot of heat.


The reason I'm not covering the entire hull is mass. The RCC is heavy and brittle. Every system on the vessel will be vital, so the entire vessel would have to be covered, including the propellant tanks, which would seriously injure mass ratio. You'd be forced to make it thinner, and it would not be worth all the added mass for it's effectiveness. Because it'd literally be covering the hull, it also would have zero effectiveness as a whipple shield.

In short, covering the entire vessel would seriously damage mass ratio, payload, would make it far less effective, destroy it's Whipple shield capability, and probably isn't even possible, considering you'd have to cover radiators, docking lines, any missiles you're carrying, communications, engines, etc. etc.

As for the engines, you'd have to cover the nozzles, making them unusable while they're shielded.

I wouldn't be so sure of that. The problems with lasers are beam dispersion and targeting- but they'll get to the target faster than a missile. It takes quite an amount of time to send a missile over a megameter, say, even if it is travelling at several km/s.

I think an effective analogy here might be U.S. Naval warfare doctrine v.s. Soviet naval warfare doctrine.

Okay, I know space isn't an ocean, and wouldn't even be considered a navy, don't think I'm thinking that, I'm not.

But, this is a case where you have two options for attacking the enemy:
A: Much slower, but is longer-ranged and carries a larger armament.
B: Faster, but carries a smaller armament and less destructive power. Also easier to block.

The U.S. Navy has gone with A, carrier-based aircraft, while the Soviet Navy went with B, cruise missiles, as the backbone of naval offense. (Granted, the U.S. Navy uses cruise missiles, but for large-scale warfare, the plan is to use aircraft carrying missiles. So aircraft are the backbone of the U.S. navy, so carriers are, which is why the U.S. has so many)

Even among cruise missiles, U.S. missiles are much, much slower, but also have a much longer range, ~250 miles for Tomahawk Antiship Missiles (TASM), or 1,300 + miles for Tomahawk Land Attack Missiles.

Lasers are faster, but they have less destructive power at long ranges, and are effectively shielded from by the RCC Whipple/Shadow Shield (WSS) except at extremely close range, when vaporizing it would actually be possible.

Meanwhile missiles, although slower, are much longer ranged (in fact, with a Delta-Vee of 3 stages of LOX/CH4, about unlimited range), carry far more destructive power (Nuclear shaped-charge FlaK, or Nuclear thermal laser, delivered right into your enemy's face), and fired in large numbers can swarm an penetrate enemy PDS, and while whipple shielding offers some protection, firing in large numbers allows them to approach from the sides and flank the enemy vessel.
You don't even have to flank the enemy's WSS, your missiles do that for you. You could even use them as smaller platforms to carry lasers to flank the enemy vessel.

If you're trying to overheat an enemy vessel, you probably won't be very effective at killing them- it could take quite a long time, during which they could dump material overboard to remove heat (they could even use propellant if they were desperate).

But as long as you're heating them more than yourself, you're forcing them to either build an active cooling system and/or dump propellant and lose Delta-Vee. Keep going, and you may force them to start shutting down systems, until eventually they either have to surrender, shut down ECLSS, or die of heat exhaustion.

I suggest all-liquid, all-storable. To get considerable dV, solids are at a penalty. Hypergolics are the first choice, but they're toxic, corrosive, and expensive. CH4 and LOX might be a good combination... you would only fuel them up before a battle, obviously.

You could also try a LOX/aluminium hybrid rocket. You'd probably need some sort of polymer binder to contain the powdered aluminium though.

CH4/LOX for the large-propellant-mass systems, the main boosters, while hypergolics could be used for the relatively low-mass RCS system.

LOX/Al rockets get about the same ISP as solids. If I were to use those, I'd might as well use solids since they can be stored fully fueled. Only reason to use LOX/Al would be the moon, where Aluminum is easy to get.


Mmm, what about gatling guns or smaller rockets as CIWS? Of very little effectiveness at long range (except interceptor missiles), but at shorter range the CIWS could serve as a last line of defense. If it uses regular chemical gun rounds, then it would be fired with no external systems needed and extremely low complexity, and even no waste heat if the shell casings could be made of a material that absorbs heat, and the inside of the barrel made reflective on IR spectrum, so that the heat is carried away in the shell casings.

[ame=http://en.wikipedia.org/wiki/Phalanx_CIWS]Phalanx-style CIWS[/ame] might have very little capabilty, but is wholly unique in simplicity and lack of requirements for external systems compared to any other weapon. It could serve as a last line of defense for short-range. And in the vacuum of space it's range isn't limited by atmospheric drag, and lack of atmosphere may make it more accurate, as well.


Now, PDS lasers will have a limited Rate of Fire (RoF) because of heating and electrical power production.
You can run them off of stored power and have tanks for active cooling to drastically increase RoF, but this means limiting your number of shots.

You could fire the lasers normally, using radiative cooling and power as it's produced, if there's no need for the higher RoF. But if that's not enough RoF to handle the volume of incoming missiles, you could switch to active cooling and stored power.

But if you're number of shots are limited, and each shot takes active cooling mass, why not use interceptor missiles? They could be very small and lightweight, missiles with solid propellant could be fired with no prepping necessary, are extremely reliable, and unlike lasers, can't be shielded against by RCC, active cooling or an ablative heat shield (a sort of active cooling).

Something the size and mass of an AMRAAM or Sidewinder might even be possible, AMRAAM or SM-2 for longer range, and Sidewinder for PDS.


Notice so far I haven't mentioned reflecting lasers. That's because AFAIK, there is no way to reflect microwaves. I'd like to know if I'm wrong, though...

 

[T.Neo]

Your laser whipple shield... won't work against lasers. Mirror armor won't work against lasers. The only effective defence against a laser is armor- a thick layer of material that is difficult to ablate. Or maybe a sort of compartment filled with a gas or a collection of fluid droplets or mini-reflects that diffuse the laser beam.

Your RCC panels- if arranged as seperated plates as in a whipple shield- would be quite effective as defending against kinetic kill vehicles. But a laser- if powerful enough- could just burn through the thin layer(s) of RCC, just as they would burn through thin layers of steel, aluminium, or graphite-epoxy, regardless of any cooling systems or radiators.

Lasers aren't easier to block. But they are more difficult to operate. Nukes are probably the best option in terms of technological ease, compared to lasers or rail/coilguns- a nuke doesn't have to worry about not destroying its powersource.

A nuke-enabled missile would still encounter some of the problems of a conventional missile, but would have a more effective payload. To consider the technological requirements for nukes vs. those of lasers, there are thousands of nuclear warheads fielded today of the yield that could be used often in space combat, but lasers are currently low-powered and experimental.

But as long as you're heating them more than yourself, you're forcing them to either build an active cooling system and/or dump propellant and lose Delta-Vee. Keep going, and you may force them to start shutting down systems, until eventually they either have to surrender, shut down ECLSS, or die of heat exhaustion.

They would probably end up dumping a minimal amount of propellant for cooling. They could also use radiators if the geometry was right, of course.

And they can still fire back at you during this.

CH4/LOX for the large-propellant-mass systems, the main boosters, while hypergolics could be used for the relatively low-mass RCS system.

I just explained the problems with hypergolics...

LOX/Al rockets get about the same ISP as solids. If I were to use those, I'd might as well use solids since they can be stored fully fueled. Only reason to use LOX/Al would be the moon, where Aluminum is easy to get.

Yes, but they're throttleable, they can be shut down, and they could be restartable. And they are completely inert when not filled with LOX.

Mmm, what about gatling guns or smaller rockets as CIWS? Of very little effectiveness at long range (except interceptor missiles), but at shorter range the CIWS could serve as a last line of defense. If it uses regular chemical gun rounds, then it would be fired with no external systems needed and extremely low complexity, and even no waste heat if the shell casings could be made of a material that absorbs heat, and the inside of the barrel made reflective on IR spectrum, so that the heat is carried away in the shell casings.


Phalanx-style CIWS
Phalanx-style CIWS might have very little capabilty, but is wholly unique in simplicity and lack of requirements for external systems compared to any other weapon. It could serve as a last line of defense for short-range. And in the vacuum of space it's range isn't limited by atmospheric drag, and lack of atmosphere may make it more accurate, as well.

Er... yeah. Maybe. Would work well against nukes, not so well against KKVs, unless the debris still missed you entirely.

Also, no gun can have zero waste heat. Cartridge cases, made of brass, are already integral to removing some waste heat, but a lot of waste heat goes into the barrel, for example. And a funny coating won't help there- there is friction in the barrel from the round being accelerated and spun up. If anything, that'd just abrade away any IR coating.

can't be shielded against by RCC, active cooling or an ablative heat shield (a sort of active cooling).

None of those things could effectively shield against lasers, except maybe a kind of ablative strategy, but you'd need a lot of it and it could cause problems.

Notice so far I haven't mentioned reflecting lasers. That's because AFAIK, there is no way to reflect microwaves. I'd like to know if I'm wrong, though...

Reflective armor doesn't help much, because even if you have a mirror that is 99% reflective, you still have 1% of that energy coming in, and it's likely going to be enough to greatly reduce the reflectivity of the material and thus ensure continued ablation.

Also, in regards to... microwaves...

1. What do microwaves specifically have to do with the laser, which as far as I know, is a term limited to systems operating in the IR-UV range, as opposed to a maser, which uses microwaves?

2. If microwaves can't be reflected, how can I stand half a meter away from a microwave and not be cooked (or at least feel some heating)?

3. If microwaves can't be reflected, how does radar, a system that relies in the reflection of transmissions in that general spectrum, work?

 

[Ghostrider]

Actually, the best effective defence against lasers is distance. A laser that can punch a hole in RHA at 5000 meters will maybe fry your electronics at 50000 while a kinetic projectile will retain its lethality even after 5 parsecs. Mind you, frying the electronics of an enemy ship may still count as a mission kill, and this isn't too shabby.

To quote Char Aznable, the best defence against a beam gun is avoid having it pointed at you, but if DEW fire exchange is unavoidable at close range it's basically an armor thing. You need armor that can take punishment from kinetic projectiles, shaped charges and beams or peebees.

My bet would be sandwiching ablating material between plates, so that any beam that penetrates the plate causes the material to vaporize absorbing the energy and dispersing it into space - the more energy you can disperse, the less is left to cause thermal shock. If you can spare enough space for the armor, you can absorb enough punishment to give you a chance to to fire back and force the enemy to break off the attack.

 

[T.Neo]

The difference of course is while a KKV will be as effective at any range (generally- orbital mechanics can come into play), a laser will reach the target much faster than a KKV (unless you have a seriously fast KKV).

The problem with ablative armor is... say I have a piece of polystyrene, for example, and I use it as ablative armor. If you fire at that with a laser, the laser will ablate through it, and then continue to ablate stuff... including the hull, and the systems, people and armaments inside.

 

[Ghostrider]

Don't know if it has already been suggested, but is it feasible to have ablative material that, upon vaporization, causes beam scattering?
In any exchange of fire, armor should buy you time to kill your enemy, unless both parties have equally strong armor and equally not strong enough weapons, like at Hampton Roads, resulting in a stalemate.

 

[T.Neo]

Maybe. Gaseous materials or particles will also disperse and lose effectiveness, which means a pulsed laser could be advantageous for ablating through material more easily.

 

[Eagle1Division]

Your laser whipple shield... won't work against lasers. Mirror armor won't work against lasers. The only effective defence against a laser is armor- a thick layer of material that is difficult to ablate. Or maybe a sort of compartment filled with a gas or a collection of fluid droplets or mini-reflects that diffuse the laser beam.

Your RCC panels- if arranged as seperated plates as in a whipple shield- would be quite effective as defending against kinetic kill vehicles. But a laser- if powerful enough- could just burn through the thin layer(s) of RCC, just as they would burn through thin layers of steel, aluminium, or graphite-epoxy, regardless of any cooling systems or radiators.

Lasers aren't easier to block. But they are more difficult to operate. Nukes are probably the best option in terms of technological ease, compared to lasers or rail/coilguns- a nuke doesn't have to worry about not destroying its powersource.

A nuke-enabled missile would still encounter some of the problems of a conventional missile, but would have a more effective payload. To consider the technological requirements for nukes vs. those of lasers, there are thousands of nuclear warheads fielded today of the yield that could be used often in space combat, but lasers are currently low-powered and experimental.

"near" range: You're enemy is close enough that the laser imparts enough heat per square unit area to vaporize the material, causing explosive decompression on your vessel.

"far" range: Because of beam dispersion, you're far enough away that the enemy's lasers won't immediantly vaporize a layer of material, but will impart a significant amount of heat on your vessel - which you'll be forced to either radiate or die.

The laser defense part of the RCC shield is for "far" ranges. It will buy you some time for "near" ranges, because they'll have to blast the shield away before they can get to your vessel, perhaps valuable life-saving time, but that's not it's purpose. It's purpose is for "far" ranges, to keep you from frying in your own ship.


I hadn't originally intended for multiple WSS's, when I said layers I meant physically connected - the only way the titanium mesh could hold the RCC in place even if it were to be fragmented.

Extra, spatially separated layers would certainly help for whipple shield purposes, as in multiple whipple shields, though only the first layer would effectively block lasers, so any secondary whipple-only shields would be built out of something much lighter than RCC, such as titanium.

Sure, fabric or any material will work, but you don't want the whipple shield to break apart after a single minor impact, so you still want a good amount of strength - and for that, a lightweight and strong material - such as titanium or aluminum.

A harder material will also do a much better job of fragmenting the incoming object. I.e., dropping a ceramic plate on cloth won't do anything, but dropping it on cement will shatter it. Despite the fact we're dealing with different materials and much higher velocities, the same principle still applies.

You want to "shatter" incoming objects with whipple shield, so the harder the material - the better. But if it's brittle, then it'll shatter. So I think high-grade Titanium fits the requirements the best of any conventional materials for pure whipple-shield.

They would probably end up dumping a minimal amount of propellant for cooling. They could also use radiators if the geometry was right, of course.

And they can still fire back at you during this.

"far" range. I covered this a few pages back in the thread... :shifty:

You know what happens if a vessel has more heat than it can radiate... It's not pretty. And just keep on firing and you'll force them to dump all their propellant, and then they'll have zero Delta-Vee and no way to stay cool. Anything you do to harm your enemy is a good tactic - even if it's just forcing them to dump some propellant. If it harms them more than you, then it's a net gain.

I just explained the problems with hypergolics...

Low-mass RCS systems. So there's only a small amount to handle. As Apollo CSM, LEM, the STS, every unmanned space probe and countless other space and orbital vehicles are designed, hypergolics make great RCS propellant. The military even uses them in ICBM's. I'd model the AEM's after ICBM's as much as possible.

Yes, but they're throttleable, they can be shut down, and they could be restartable. And they are completely inert when not filled with LOX.

Ah, ok. But why use them over CH4/LOX? Is it the fact that only the oxidizier is cryogenic, and not the fuel? That makes a certain amount of sense, but Idk if it's worth 370 - 270 seconds ISP.

Er... yeah. Maybe. Would work well against nukes, not so well against KKVs, unless the debris still missed you entirely.

Also, no gun can have zero waste heat. Cartridge cases, made of brass, are already integral to removing some waste heat, but a lot of waste heat goes into the barrel, for example. And a funny coating won't help there- there is friction in the barrel from the round being accelerated and spun up. If anything, that'd just abrade away any IR coating.

The whipple shield will have a much easier time handling fragments of a KKV rather than an entire KKV.

1. What do microwaves specifically have to do with the laser, which as far as I know, is a term limited to systems operating in the IR-UV range, as opposed to a maser, which uses microwaves?

Just a mistake of terminology. I meant maser...

2. If microwaves can't be reflected, how can I stand half a meter away from a microwave and not be cooked (or at least feel some heating)?

I've always assumed they are absorbed, not so much reflected. The microwave walls are always very warm afterwards, they wouldn't be as hot as the thing being microwaved, because whatever is being microwaved absorbs the majority of the heat, shielding the walls, and the walls have a higher mass, so more energy is needed to heat them (really... Microwaves are heavy! )

But Idk, maybe there is reflection involved. I somewhat doubt it just because microwaves are so unique and have such a high energy, but maybe, and if so, I'd like to know what material does so and at what efficiency.

3. If microwaves can't be reflected, how does radar, a system that relies in the reflection of transmissions in that general spectrum, work?

The special thing about radio is how it interacts with metals. Only metals reflect it, which is what makes it so useful. Microwaves in a microwave oven only heat water, radio doesn't, so I think it's fairly safe to assume the different frequencies have very different properties. For further example, certain types of radio can reflect off the upper atmosphere, obviously the visual spectrum doesn't... (Though that would be quiet an amazing sight!)

 

[T.Neo]

"near" range: You're enemy is close enough that the laser imparts enough heat per square unit area to vaporize the material, causing explosive decompression on your vessel.

Or it could kill you directly or indirectly (ablation, supersonic shock, or shrapnel), damage flight-critical hardware directly or indirectly (ablation, supersonic shock, or shrapnel), or hit a propellant tank, which would be... ouch.

"far" range: Because of beam dispersion, you're far enough away that the enemy's lasers won't immediantly vaporize a layer of material, but will impart a significant amount of heat on your vessel - which you'll be forced to either radiate or die.

Or you could eject coolant to shed heat.

Or... you could just fire your RCS thrusters and get out of the way.

The laser defense part of the RCC shield is for "far" ranges. It will buy you some time for "near" ranges, because they'll have to blast the shield away before they can get to your vessel, perhaps valuable life-saving time, but that's not it's purpose. It's purpose is for "far" ranges, to keep you from frying in your own ship.


I hadn't originally intended for multiple WSS's, when I said layers I meant physically connected - the only way the titanium mesh could hold the RCC in place even if it were to be fragmented.

Extra, spatially separated layers would certainly help for whipple shield purposes, as in multiple whipple shields, though only the first layer would effectively block lasers, so any secondary whipple-only shields would be built out of something much lighter than RCC, such as titanium.

Sure, fabric or any material will work, but you don't want the whipple shield to break apart after a single minor impact, so you still want a good amount of strength - and for that, a lightweight and strong material - such as titanium or aluminum.

A harder material will also do a much better job of fragmenting the incoming object. I.e., dropping a ceramic plate on cloth won't do anything, but dropping it on cement will shatter it. Despite the fact we're dealing with different materials and much higher velocities, the same principle still applies.

You want to "shatter" incoming objects with whipple shield, so the harder the material - the better. But if it's brittle, then it'll shatter. So I think high-grade Titanium fits the requirements the best of any conventional materials for pure whipple-shield.

Titanium is expensive and difficult to work with.

Just use aluminium. The throwing stuff onto concrete analogy doesn't make sense at hypervelocity, as far as I know- if you crashed into a pillow-case or a cinderblock at 7 km/s, I don't really think it would matter.

RCC is brittle and also highly, highly expensive.

Several layers of thin aluminium would do the job fine and cost a tiny fraction of your system. Granted, they wouldn't be very good at stopping lasers... but I absolutely fail to see the value of your system as laser armor.

You know what happens if a vessel has more heat than it can radiate... It's not pretty. And just keep on firing and you'll force them to dump all their propellant, and then they'll have zero Delta-Vee and no way to stay cool. Anything you do to harm your enemy is a good tactic - even if it's just forcing them to dump some propellant. If it harms them more than you, then it's a net gain.

Er, yeah. The problem is, when your means of harming them is inefficient and limiting on more effective ways to harm them, then it is actually harming you.

They can dump a tiny amount of their propellant and also constantly shift themselves to make firing on them difficult.

Low-mass RCS systems. So there's only a small amount to handle. As Apollo CSM, LEM, the STS, every unmanned space probe and countless other space and orbital vehicles are designed, hypergolics make great RCS propellant. The military even uses them in ICBM's. I'd model the AEM's after ICBM's as much as possible.

I dare you to drink some nitrogen tetroxide.

Or no, I actually dare you to... make a glass of nitrogen tetroxide.

On the Moon.

And are you really going to double your RCS system mass because you're not using hypergolics? Yeah, I dunno...

Ah, ok. But why use them over CH4/LOX? Is it the fact that only the oxidizier is cryogenic, and not the fuel? That makes a certain amount of sense, but Idk if it's worth 370 - 270 seconds ISP.

The fact that you can make it with lunar materials (kinda, you'd need to import the binder).

AFAIK the difference in ISP is less than you think- maybe more like... 80 or 90 seconds.

The whipple shield will have a much easier time handling fragments of a KKV rather than an entire KKV.

Debatable. Might be easier dealing with a better whipple shield than a set of CIWS systems.

I've always assumed they are absorbed, not so much reflected. The microwave walls are always very warm afterwards, they wouldn't be as hot as the thing being microwaved, because whatever is being microwaved absorbs the majority of the heat, shielding the walls, and the walls have a higher mass, so more energy is needed to heat them (really... Microwaves are heavy! )

As far as I know the microwaves bounce around in the microwave to get to the food. The magnetron doesn't even point at the food directly.

And walls being warm could be due to other reasons- such as water vapour being heated within the microwave.

But Idk, maybe there is reflection involved. I somewhat doubt it just because microwaves are so unique and have such a high energy, but maybe, and if so, I'd like to know what material does so and at what efficiency.

Microwaves aren't high energy. As far as I know, a microwave photon contains less energy than a green photon (just as a visual-light photon has less energy than an X-ray or gamma ray photon). But I know absolutely nothing about photons and light and frequencies of radiation and whatnot, so take anything I mumble with a grain of salt...

The special thing about radio is how it interacts with metals. Only metals reflect it, which is what makes it so useful. Microwaves in a microwave oven only heat water, radio doesn't, so I think it's fairly safe to assume the different frequencies have very different properties. For further example, certain types of radio can reflect off the upper atmosphere, obviously the visual spectrum doesn't... (Though that would be quiet an amazing sight!)

Yes, different frequencies of electromagnetic radiation interact with things differently. Are you sure radio waves do not heat water? All electromagnetic radiation can impart energy- even visual radiation will heat water a bit. The difference is how much, based on the interactions of that particular part of the spectrum.

I think.

 

[APDAF]

How about the old battleship line?

 

[T.Neo]

I'm not sure. Maybe it would work. Have they ever tried doing it with those air-crafts?

 

[APDAF]

In space you cannot change direction quickly as we all know and the battleship line means to do not have to change direction much.

 

[Sky Captain]

If your tech are advanced enough you could equip your warships with X ray lasers that have effective ranges of light minutes against targets on predictable course. Defending against X ray laser attack would require heavy radiation shielding or your crew and electronics will get fried.

 

[T.Neo]

In space you cannot change direction quickly as we all know and the battleship line means to do not have to change direction much.

In space, you change direction differently. You move differently. It is a three-dimensional environment, not a two-dimensional environment.

If your tech are advanced enough you could equip your warships with X ray lasers that have effective ranges of light minutes against targets on predictable course. Defending against X ray laser attack would require heavy radiation shielding or your crew and electronics will get fried.

Don't X-ray lasers have to be constructed out of nuclear bombs or particle accelerators? I'd imagine that'd hurt the practicality of such a device.

 

[fsci123]

I was investigating the feasibility of laser shielding and it shows that having an armour made of hard ablatof would be partcularly ineffective because the ablatof may absorb heat from the laser and transfer it to the hull itself. Wouldn't it be more effective to have some type of light ablato.

I was also wondering if one could stop incoming projectiles with plates that eject themselves toward and oncoming threat.

And is it possible to ignite fusion fuel in a leaking fuel tank by aiming a light sail laser at it?

 

[Urwumpe]

Microwaves are electromagnetic waves... just like lasers and radio. Microwaves just operate mostly in the cm band, that is all (not in the micrometer band, as you might expect, the maximum is 3mm or 100 GHz)

If something ablates (ablative armor.. not sure what you call ablatof, maybe some kind of Russian chef), this means it melts away in a endothermic reaction (energy is reduced) and does NOT transfer heat to inside. The heat is ejected with the molten ablative. ablative armor is especially powerful against non-pulsed laser, since the vapor cloud formed by the ablation scatters the laser. Pulsed lasers simply wait until the cloud is gone.

Reactive armor is possible, but pretty ineffective and often a bigger danger to friendly units that operate near you, than the enemy. Current technology is using smart sensor systems that fire shrapnel precisely in the direction of the attack.

And no, you can't even ignite fusion fuel in a leaking fuel tank if you would explode a nuclear bomb right next to it. It is pressure AND heat, not pressure or heat.

 

[T.Neo]

Fusion and even fission require precise conditions to occur. You can most definitely not just shine a laser at something and expect fusion to occur, if it was this easy we would nearly have fusion reactors in houses by now...

 

[fsci123]

Microwaves are electromagnetic waves... just like lasers and radio. Microwaves just operate mostly in the cm band, that is all (not in the micrometer band, as you might expect, the maximum is 3mm or 100 GHz)

If something ablates (ablative armor.. not sure what you call ablatof, maybe some kind of Russian chef), this means it melts away in a endothermic reaction (energy is reduced) and does NOT transfer heat to inside. The heat is ejected with the molten ablative. ablative armor is especially powerful against non-pulsed laser, since the vapor cloud formed by the ablation scatters the laser. Pulsed lasers simply wait until the cloud is gone.

Reactive armor is possible, but pretty ineffective and often a bigger danger to friendly units that operate near you, than the enemy. Current technology is using smart sensor systems that fire shrapnel precisely in the direction of the attack.

And no, you can't even ignite fusion fuel in a leaking fuel tank if you would explode a nuclear bomb right next to it. It is pressure AND heat, not pressure or heat.

Wait wait wait...
Wouldn't your nearest ally be at least a few miles away if not a few hundred. A cluster of ally spacecraft organized in less than 5 miles^3 would be a bad thing considering that if one vessel gets penetrated with a kill-vehicle the other would be damaged by either the shrapnel or the part of the kill vehicle that slips through the other end.

 

[Urwumpe]

Wait wait wait...
Wouldn't your nearest ally be at least a few miles away if not a few hundred. A cluster of ally spacecraft organized in less than 5 miles^3 would be a bad thing considering that if one vessel gets penetrated with a kill-vehicle the other would be damaged by either the shrapnel or the part of the kill vehicle that slips through the other end.

Maybe you should read about space debris again: Space debris knows no range limits.

Given enough time, the velocity differences between fragments in a debris cloud will result in the cloud covering the whole planet - take about one half of a year in LEO.

In space combat: Everything you fire away, will not stop until it hits something else. And even then the fragments of the impact will keep on flying.

Also, ships are about 5 km apart usually in a modern formation, but still that is close enough to enforce rules on engagement zones. There are many examples in which defense systems misfired at another ship and you can bet, future systems will not be without such flaws.