Scenario of War with the League

darrell wrote:A properly designed faraday cage will block over 99% of the EMP, and I would be willing to bet that missile pods have faraday cages built in.

You would probably lose that bet. We are explicitly told that pods are "vulnerable to soft kills," which would imply thay are NOT hardened against EMP.

"Faraday Cages" or just shielded wiring adds cost to what is essentially a throwaway casing for a group of missiles. Pods can be reused if they can be recovered, but they aren't actually built with recovery in mind.

To NOT be a faraday cage, an exterior shell material must not be conductive... So, to block the majority of the EMP, all the RMN/GSN/IAN/HN/SLN has to do is make the shell out of aluminum, magnessium, or any other metal or slightly conductive ceramic. Of course you still have all of your ports as EMP is skin effect by and large. Going to assume, with justification IMO,that the missile launch tubes are easily covered and grounded. Leaves the C&C and attitude adjustment ports along with the tractor.

Grounding receivers is very difficult. In short you have to have rotating transceivers as there is no way to block the EMP going down the antenna into the balun and op amp. So, the most important part is the balun. Spikes can be mitigated. One little known fact is that this is often the most complex and expensive part on military radios of all types today.

Of course we are supposed to believe that in 2000+++ years in a space going society where EMP(solar flares etc) is a MUCH larger concern than on earth, that every single antenna design in the HV will have EMP neutralization in its design and construction. Complete bollocks to think this would not be the basis of every single radio ever produced for any space going ship in the HV. They should be as cheap as a toy that comes in your cereal box.

So, IMO that leaves the tractor port as the major part that needs grounding. As this is handwavium tech it may or may not be possible to EMP ground it. Even if they could not ground the tractor, this would not "soft-kill" the pod. Just means the tractor would be knocked out. I find it highly dubious that in a space going society tractors would not be EMP shielded. It should be more expensive to build non shielded space parts as such designs shouldn't exist from off the shell assemblies.

Of course even assuming that said nuke get "coned" into 60 degrees, that still leaves the nuclear warhead several thousand Trillion times too small to even tickle the pods at 30,000km.

Jonathan_S wrote:Sorry, I misunderstood. You meant the grav "lensing" system that focusing the nuclear blast forwards; not the laser lensing that focuses the laser beams.

That's a good point, the majority of the nuke's blast is getting projected in a more concentrated cone forwards. So the EMP or whatever from the laser head's nuke probably looks more like a shotgun blast than a grenade blast.
It can kill pods up to 30,000 km away, but probably only in a 60-90 degree cone; not in a 360 sphere.

Still if we assume a 60 degree cone that's every pod at 30,000 km within a roughly 942,531,332 sq-km circular area. OTOH, if I didn't screw the match up, big as that is that's still only 1/12th the surface area of the entire 30,000 km radius sphere.
So yes, you'd need more nukes to 'plow the road' of probably pods - but still doable should you be able to make reasonable guesses as to where those pods would have to be.

I would think even 60 was very optimistic. I'm thinking it's more like a few degrees.

Loren Pechtel wrote:I would think even 60 was very optimistic. I'm thinking it's more like a few degrees.

4/3PIr^3 If 5Mt = 10km r ~50Mt(RMN warhead) ~= 20km = r

Area = 33.5E3km^2

IF targeting pods, @30,000km. Assume targetting area swept is a cone with radius 100km

100km radial cicle has an area of ~31.4km^2

31.4~=~33.5

angle... arcsin(100/30,000)

Angle = 0.19 degrees...

Rod length is 10m-20m or so. They need separation. Call it 10m at least. Shoot forward then rotate. Make llllll

So, say, 100m-1000m forward of nuclear blast. arcsine(10/100) = 6 degrees cone
arcsine(10/1000) = 0.6 degree cone.

6 >> 0.6 >> 0.19

In either case, even in an extreme 1km forward position, to kill a pod at 30,000km a nuclear blast cannot even hit its own laser rods to activate them. Note above, I assume near perfect nuclear blast/laser rod orientation.

Since at small angles ~sin is linear. Lets calc distance a pod can be killed.

If 6 degrees = distance of approx 1000km is best case
tan6 = 0.1 with a radial cone of 100km = 1000km(see above)

So, with all those assumptions..... decided to do a better calc...

Relax wrote:

Loren Pechtel wrote:I would think even 60 was very optimistic. I'm thinking it's more like a few degrees.

4/3PIr^3 If 5Mt = 10km r ~50Mt(RMN warhead) ~= 20km = r

Area = 33.5E3km^2

IF targeting pods, @30,000km. Assume targetting area swept is a cone with radius 100km

100km radial cicle has an area of ~31.4km^2

31.4~=~33.5

angle... arcsin(100/30,000)

Angle = 0.19 degrees...

Rod length is 10m-20m or so. They need separation. Call it 10m at least. Shoot forward then rotate. Make llllll

So, say, 100m-1000m forward of nuclear blast. arcsine(10/100) = 6 degrees cone
arcsine(10/1000) = 0.6 degree cone.

6 >> 0.6 >> 0.19

In either case, even in an extreme 1km forward position, to kill a pod at 30,000km a nuclear blast cannot even hit its own laser rods to activate them. Note above, I assume near perfect nuclear blast/laser rod orientation.

Since at small angles ~sin is linear. Lets calc distance a pod can be killed.

If 6 degrees = distance of approx 1000km is best case
tan6 = 0.1 with a radial cone of 100km = 1000km(see above)

So, with all those assumptions..... decided to do a better calc...

Lasing rods are 3 meters for Mk-16's and 5 meters for Mk-23's (I've mentioned this several times over the past couple years in various threads). Rods move forward 150 meters from the warhead prior to detonation (I may or may not have mentioned this).

Relax wrote:
To NOT be a faraday cage, an exterior shell material must not be conductive... So, to block the majority of the EMP, all the RMN/GSN/IAN/HN/SLN has to do is make the shell out of aluminum, magnessium, or any other metal or slightly conductive ceramic. Of course you still have all of your ports as EMP is skin effect by and large.

skip

Of course even assuming that said nuke get "coned" into 60 degrees, that still leaves the nuclear warhead several thousand Trillion times too small to even tickle the pods at 30,000km.

Very interesting points!!!

In the real universe, for example, solar cells can be damaged by at least some EMP. For protection while still allowing operation, wrapping .027 inch wire galvanized bug screen around it (back as well as front) almost works. Protection against the wire acting as an antenna needs to be added. The most effective protection here seems to be a good ferrite inductance around the wire just at the point where the screen is. This blocks the higher frequencies, while letting the DC or low frequency to pass.

IMHO, now that it has been brought up, it should be trivial to harden missile pods against soft kills. There is one question tho, mention is made that missile pods are stealthy. Can anyone provide information on whether stealth technology would need to interfere with EMP protection

DDHv wrote:

Relax wrote:
To NOT be a faraday cage, an exterior shell material must not be conductive... So, to block the majority of the EMP, all the RMN/GSN/IAN/HN/SLN has to do is make the shell out of aluminum, magnessium, or any other metal or slightly conductive ceramic. Of course you still have all of your ports as EMP is skin effect by and large.

skip

Of course even assuming that said nuke get "coned" into 60 degrees, that still leaves the nuclear warhead several thousand Trillion times too small to even tickle the pods at 30,000km.

Very interesting points!!!

In the real universe, for example, solar cells can be damaged by at least some EMP. For protection while still allowing operation, wrapping .027 inch wire galvanized bug screen around it (back as well as front) almost works. Protection against the wire acting as an antenna needs to be added. The most effective protection here seems to be a good ferrite inductance around the wire just at the point where the screen is. This blocks the higher frequencies, while letting the DC or low frequency to pass.

IMHO, now that it has been brought up, it should be trivial to harden missile pods against soft kills. There is one question tho, mention is made that missile pods are stealthy. Can anyone provide information on whether stealth technology would need to interfere with EMP protection

Probably depends on the Stealth technology. The B-2, according to several sources I've read, has a copper mesh behind the skin to absorb radio frequencies, which would help in hardening against EMP. Standard fiberglass structures are transparent to radio frequencies, so have been used make a structure transparent to radar, and reduce the overall return - but would not be hardened against EMP.

Theemile wrote:

DDHv wrote:Very interesting points!!!

In the real universe, for example, solar cells can be damaged by at least some EMP. For protection while still allowing operation, wrapping .027 inch wire galvanized bug screen around it (back as well as front) almost works. Protection against the wire acting as an antenna needs to be added. The most effective protection here seems to be a good ferrite inductance around the wire just at the point where the screen is. This blocks the higher frequencies, while letting the DC or low frequency to pass.

IMHO, now that it has been brought up, it should be trivial to harden missile pods against soft kills. There is one question tho, mention is made that missile pods are stealthy. Can anyone provide information on whether stealth technology would need to interfere with EMP protection

Probably depends on the Stealth technology. The B-2, according to several sources I've read, has a copper mesh behind the skin to absorb radio frequencies, which would help in hardening against EMP. Standard fiberglass structures are transparent to radio frequencies, so have been used make a structure transparent to radar, and reduce the overall return - but would not be hardened against EMP.

making the shell out of fiberglass wouldn't help. the radar beam would go trough the fiberglass, bounce off the box launchers, fusion reactors, etc. Next the radar beam would go back through the fiberglass on it's way back to the receiver.

DDHv wrote:IMHO, now that it has been brought up, it should be trivial to harden missile pods against soft kills. There is one question tho, mention is made that missile pods are stealthy. Can anyone provide information on whether stealth technology would need to interfere with EMP protection

There really is no EMP in Space on anywhere close to the scale needed for the effects David wanted.
http://www.projectrho.com/public_html/r ... nt.php#emp

So, like the whole triple ripple, it works because David says it works.

darrell wrote:

Theemile wrote:
Probably depends on the Stealth technology. The B-2, according to several sources I've read, has a copper mesh behind the skin to absorb radio frequencies, which would help in hardening against EMP. Standard fiberglass structures are transparent to radio frequencies, so have been used make a structure transparent to radar, and reduce the overall return - but would not be hardened against EMP.

making the shell out of fiberglass wouldn't help. the radar beam would go trough the fiberglass, bounce off the box launchers, fusion reactors, etc. Next the radar beam would go back through the fiberglass on it's way back to the receiver.

Totally correct. I wasn't referencing it in this propose, but as a general material used in stealthy platforms - Iirc portions of the wings and tail of the U2 featured fiberglass for it's transparence, allowing a large shape to have a much small return.

In addition, the fiberglass can be the aerodynamic surface shape while the internal structure is "faceted" as to disperse and reflect the radar return away from receiver. This was the next step in stealth design past the F-117a "Faulty Diamond" shaping, where the dispersing panels also had to be aerodynamic surfaces.

Once again, not a technology necessarily used here, but one used in stealth designs.