Exploring the Plausibility of SF Energy Shield Alternatives

[GTOM]

What could be the things closest to a SF energy shield?

Even the strongest known materials couldn't stop shrapnels hit with 100 km/s. On the other hand, whipple shields are pretty efficient against high speed/low mass threats, the first armor plating disperse the micrometeor, then the second can stop it. A ship can have a shield before it in big distance. It is even better, if the incoming mass is ionized by the impact energy, so an electric or magnetic field can redirect it.
Probably the ship can have a minirobot cloud before it. The scale like bots (moved by tethers or electromagnetic fields) can cluster to shatter bigger shrapnels, or disperse against micrometeor cloud. If they get power from the ship, they can deliver ionization level energy to incoming material.
They can also disperse beams with diffraction. Of course that energy eventually melts them, but they can still save the ship from lots of harm.

The ship armor also could be self-repair, or maybe liquid, held by a magnetic field? This idea came from Legend of galactic heroes.

What is the plausibility level of this methods?

 

[trurle]

https://en.wikipedia.org/wiki/Plasma_window

 

[GTOM]

https://en.wikipedia.org/wiki/Plasma_window

Thank you. But it rather looks like an airlock alternative than a shield.

 

[trurle]

Thank you. But it rather looks like an airlock alternative than a shield.

Performance of plasma window depends on power density. With modern tech, it barely holds out against 1bar. Pump several more magnitudes of power in plasma window and it will be resisting shockwaves. Resisting hyper-velocity slugs is more difficult, but powerful enough plasma window can shatter these, leaving less hazard to armour plate.

SF "Energy shields" are somewhat resemble plasma window with incredibly high Q factor (i.e. energy density is huge, but most of power is recirculating inside field), making possible charging with more realistic powers, but "raising shield" take long time. Modern plasma windows are raised in milliseconds, but dissipate as soon as charging power is removed.

If we will be able to somehow recirculate plasma window energy without huge ohmic loss (with non-existing plasma-state superconductor?) plasma window will be approaching "energy shield" behavior.

 

[Bab5space]

Given the energy required, I think plasma windows can be ruled out if working with current understanding of science only.
Either fiction or some future breakthrough or discovery is required for a spaceship to harness energy on that level and not be megastation sized because of managing the waste heat involved.

Coincidentally, the scifi weapons xnd defenses often seen in scifi would be easier implemented vy massive planet bound powerstations rather than a single spaceship.

If anything, spaceships favor less active defenses and active offense, since they lack the energy and mass to pull off good active defense anyway.

Ignore this and the scenario will likely be the biggest baddest most shielded vessel wins, or rather whoever has the economy to produce them.

Virtually unbeatable if they out tech an opponent.

 

[trurle]

Either fiction or some future breakthrough or discovery is required for a spaceship to harness energy on that level and not be megastation sized because of managing the waste heat involved

Waste heat management is actually a nightmare even for modern spacecraft . Specific power was 2 W/kg in 2010, rising to 3 W/kg in 2020, mostly due to smaller spacecraft with larger surface/volume, but also because engineers start thinking about more advanced radiators (like on Destiny+).

If anything, spaceships favor less active defenses and active offense, since they lack the energy and mass to pull off good active defense anyway.

"Kzinti lesson". No point to split resources between drive system and "weapons" because spacecraft propulsion itself is weapon.

 

[GTOM]

Spaceship propulsion is flamethrower at best.
So looks like it isn't so irreal to have Star Wars like dock, airlock without double doors.
On the other hand, if the edge of plasma shield got hit, it quickly dissipates isn't it?

 

[trurle]

Spaceship propulsion is flamethrower at best.

Think about the other side of the nozzle.
The flame-throwing part is moving at railgun speeds even with modern tech. Simplest solution for drive weaponization is the suicide probes; more advanced is minelaying probes. Even ion drives allows to build up nearly nuclear-explosion kinetic energy densities, if acceleration path is long enough.

On the other hand, if the edge of plasma shield got hit, it quickly dissipates isn't it?

Yes. Some SF novels use "shield emitters" which emit "shield" radially instead of tangentially as in plasma window, to avoid critical vulnerability. Another "tech" which have no modern equivalent.

In another thread, i used to discuss future spacecraft protection using a deploy-able Whipple shields. The conclusion was what the shielding would be likely pointless in encounter against warships (doctrine "eggs armed with hammers" in action), but shielding is going to be used anyway for high-value spaceships to serve as deterrent against low-level threats and for psychological comfort.

 

[member 656954]

What could be the things closest to a SF energy shield?

We have nothing close to an energy shield as commonly described in sci-fi, and not really any engineering ideas to create one. As @trurle noted, plasma has been mooted for limited types of protection, as have magnetic fields, but they are nothing like what we read about.

 

[Rive]

With sticking to the realistic solutions maybe some kind of multilayered ablative-reactive combination would provide the best protection. But that's definitely not an energy shield.

Regarding shields, as I see it BSG was the best. They just dropped the whole magic

 

[member 656954]

Virtually unbeatable if they out tech an opponent.

There are many examples of asymmetrical warfare where the low-tech defeated the high-tech, so that's not a given. Supply chains are critical, esp. for a high tech military. Disrupt them and you undermine the technology.

Then there is the situation where destroying the assets of the high-tech society delivers a disproportionate blow compared to hitting the assets of the low-tech society.

And, terrorists are not typically bound by law, but armies are, so low-tech terrorists can inflict considerable damage on a high-tech, but law bound, high-tech military.

 

[Bab5space]

There are many examples of asymmetrical warfare where the low-tech defeated the high-tech, so that's not a given. Supply chains are critical, esp. for a high tech military. Disrupt them and you undermine the technology.

Then there is the situation where destroying the assets of the high-tech society delivers a disproportionate blow compared to hitting the assets of the low-tech society.

And, terrorists are not typically bound by law, but armies are, so low-tech terrorists can inflict considerable damage on a high-tech, but law bound, high-tech military.

I am implying that a weaker opponent could not hope to militarily beat a technologically superior foe in space. Especially if they are outnumbered at that.

Tying one's hands behind's one back because of laws is a human concept that scifi aliens may discard, while they may care more about stuff human armies typically do not, like who is owed a strike for example?

War would be so automated that we would hardly recognize it as guys with rifles.

The only real chance a weaker foe has is infilitration and sabotage of the enemy... quite a feat considering most of the fleet would be AI run anyway.

 

[GTOM]

I am implying that a weaker opponent could not hope to militarily beat a technologically superior foe in space. Especially if they are outnumbered at that.

Tying one's hands behind's one back because of laws is a human concept that scifi aliens may discard, while they may care more about stuff human armies typically do not, like who is owed a strike for example?

War would be so automated that we would hardly recognize it as guys with rifles.

The only real chance a weaker foe has is infilitration and sabotage of the enemy... quite a feat considering most of the fleet would be AI run anyway.

That is actually a hackers dream.

 

[Bab5space]

That is actually a hackers dream.

Depends on how sophisticated and ruthless the AI he is trying to hack is does it not?

Hacking requires a link does it not? And upon a hacker being detected, I am certain the AI would be sending whatever appropriate level of force is required to 'neutralize' the threat.

Star Trek makes me laugh. Sending in away times via teleport in harm's way often when they could be sending drones.

I guess they did not foresee drone technology as being huge in the future.

If treknology was used logically battle fleets would be AI automated with hologram crew where needed.

And drones would dispatch any group of guys with phasers, since drones would be just like flying mini phaser turrets.

Drones make even the dreaded Borg look like a joke... since assimilating flying mini drones are far more efficient.

 

[GTOM]

Depends on how sophisticated and ruthless the AI he is trying to hack is does it not?

Hacking requires a link does it not? And upon a hacker being detected, I am certain the AI would be sending whatever appropriate level of force is required to 'neutralize' the threat.

Star Trek makes me laugh. Sending in away times via teleport in harm's way often when they could be sending drones.

I guess they did not foresee drone technology as being huge in the future.

If treknology was used logically battle fleets would be AI automated with hologram crew where needed.

And drones would dispatch any group of guys with phasers, since drones would be just like flying mini phaser turrets.

Drones make even the dreaded Borg look like a joke... since assimilating flying mini drones are far more efficient.

The hacker could be an AI too, that either want to wipe out humanity, or the opposite, save them from their stupid wars.

 

[Bab5space]

The hacker could be an AI too, that either want to wipe out humanity, or the opposite, save them from their stupid wars.

Well at least your keeping up with me rather than relying on outdated tactics to win.

Such a method could in theory work. But it would be limited in scope. Why?

Unlike scifi wise designers do not central control all, rather they use servers and backups, so if one section falls another will continue and so on.

An AI fleet should be at least as resilent as the internet is to nuclear attack.

 

[GTOM]

Well at least your keeping up with me rather than relying on outdated tactics to win.

Such a method could in theory work. But it would be limited in scope. Why?

Unlike scifi wise designers do not central control all, rather they use servers and backups, so if one section falls another will continue and so on.

An AI fleet should be at least as resilent as the internet is to nuclear attack.

Do you think the internet is resilient to it? I think the EMP would take most of the computers and power grids.

(In my story they definitally don't put the fate of humanity entirely to AIs)

 

[essenmein]

I mean that drone swarm idea is neat, but counter measures would be relatively easy if you assume you can apply the same level of tech to defensive machines.

1) Anti-drone drones, basically use a drone shield to attack if enemy drones are detected incoming (they will be easily detectable, noise for example).
2) that AI tracking tech could easily be used to build mini AA turrets firing high vel .177's or something (I call BS on the drones evading bullets, esp at close range). The AA gun AI could pre calculate a spread based on possible flight vectors for example.
3) Large electric field gradients would be near impossible for them to fly through. Detect drones, turn on tesla coils near points of entry (eg windows)
4) No matter how smart the AI, it still needs sensory input, these will be mostly electromagnetic in nature (optical, gps, xray lidar etc etc) so should not be to difficult to upset, again, you, since you live there, know how these things work, so finding a weakness should not be impossible.
5) Simple traps, eg array of dangling fishing line to tangle the rotors, since they move a lot of air, they will be happy to suck them in.

 

[Bab5space]

Do you think the internet is resilient to it? I think the EMP would take most of the computers and power grids.

(In my story they definitally don't put the fate of humanity entirely to AIs)

I mean that drone swarm idea is neat, but counter measures would be relatively easy if you assume you can apply the same level of tech to defensive machines.

1) Anti-drone drones, basically use a drone shield to attack if enemy drones are detected incoming (they will be easily detectable, noise for example).
2) that AI tracking tech could easily be used to build mini AA turrets firing high vel .177's or something (I call BS on the drones evading bullets, esp at close range). The AA gun AI could pre calculate a spread based on possible flight vectors for example.
3) Large electric field gradients would be near impossible for them to fly through. Detect drones, turn on tesla coils near points of entry (eg windows)
4) No matter how smart the AI, it still needs sensory input, these will be mostly electromagnetic in nature (optical, gps, xray lidar etc etc) so should not be to difficult to upset, again, you, since you live there, know how these things work, so finding a weakness should not be impossible.
5) Simple traps, eg array of dangling fishing line to tangle the rotors, since they move a lot of air, they will be happy to suck them in.

The internet was designed to survive a nuclear attack, so I doubt it would not survive a nuclear attack, although wiping out satellites would kill a lot of connectivity.

As for the drones, they are only the advance force for invading troops and machines.

Troops and vehicles neutralize threats the drone swarm cannot.

A combined arms approach would be the way I would structure a planetary invasion. The entire purpose of which would neutralize the stronghold of any resistance forces before pacifying the general population through setting up government.

 

[GTOM]

Military systems were designed to withstand harsh conditions. But i am sure most of the internet don't have any emp protection. Also we could see even solar storms make problems for civilan power grids.

 

[essenmein]

The internet was designed to survive a nuclear attack, so I doubt it would not survive a nuclear attack, although wiping out satellites would kill a lot of connectivity.

As for the drones, they are only the advance force for invading troops and machines.

Troops and vehicles neutralize threats the drone swarm cannot.

A combined arms approach would be the way I would structure a planetary invasion. The entire purpose of which would neutralize the stronghold of any resistance forces before pacifying the general population through setting up government.

You can't make things completely invincible in reality, the internet was designed to be resilient against some level of nuclear attack, but not all conceived nuclear scenarios. Fairly certain the internet won't be working if you carpet nuke the planet.

My comment was really wrt to that video link, where they gave the impression at least, that the drones were the be all end all combat system and impossible to defeat, which is very short sighted IMO. When the tiny killer drones themselves are a defensive solution.

IMO a planetary invasion would follow most "normal" invasions since we invented invasions. Bombard from a distance to soften up the enemy, take out defenses, then depending on the reason for the invasion, steam roll the population then strip resources and leave, or clear out "resistance" and install a government. Or maybe just kill everything and leave perhaps for revenge or racking up evil kudos.

 

[GTOM]

You can't make things completely invincible in reality, the internet was designed to be resilient against some level of nuclear attack, but not all conceived nuclear scenarios. Fairly certain the internet won't be working if you carpet nuke the planet.

My comment was really wrt to that video link, where they gave the impression at least, that the drones were the be all end all combat system and impossible to defeat, which is very short sighted IMO. When the tiny killer drones themselves are a defensive solution.

IMO a planetary invasion would follow most "normal" invasions since we invented invasions. Bombard from a distance to soften up the enemy, take out defenses, then depending on the reason for the invasion, steam roll the population then strip resources and leave, or clear out "resistance" and install a government. Or maybe just kill everything and leave perhaps for revenge or racking up evil kudos.

I wonder about the limits of small drones. Silicon based chips are already not so far from physical limits, present day drones still dependent on radio communications, radars, which make them vulnerable to jamming, emp attacks. There are optical processors, but i wonder, if they use interferometry, doesn't that mean, they are pretty sensitive to shakes?

Anyway there are several methods to counter drones in my story.
Planetary invasion includes fire missiles before the attack fleet decelerates to orbit. Battleships with big lasers and mass drivers. Fighters reach low orbit for search and destroy, and secure the path of shuttles deliver combat robots.

 

[trurle]

I wonder about the limits of small drones. Silicon based chips are already not so far from physical limits, present day drones still dependent on radio communications, radars, which make them vulnerable to jamming, emp attacks. There are optical processors, but i wonder, if they use interferometry, doesn't that mean, they are pretty sensitive to shakes?

Modern electronics has grown pretty EMP and jamming resistant, thanks to ever increasing deluge of background wireless networks, and reduced size of electrial parts. Current jammers (as in 2019) are barely catching up with commlink standards developed in 1995. And i suspect the "jammer lag" is still increasing.

 

[GTOM]

Modern electronics has grown pretty EMP and jamming resistant, thanks to ever increasing deluge of background wireless networks, and reduced size of electrial parts. Current jammers (as in 2019) are barely catching up with commlink standards developed in 1995. And i suspect the "jammer lag" is still increasing.

The downed usa military drone in Iran (not shot down but downed with jamming) doesn't seem to reinforce that.

 

[trurle]

The downed usa military drone in Iran (not shot down but downed with jamming) doesn't seem to reinforce that.

Well, military electronics recently is recently 20 years behind civilian. Especially in US where reliability-driven review system resulted in critical delays in fielding modern tech. Accident in 2011 prove exactly this fact.
For more relevant data, you should look onto difficulties law enforcement have recently warding off amateur drones from airports. Or mass use of drones in Syrian civil war. Russians in Hmeimin were unable to reliably jam incoming Idlib-made drones, and resorted to shooting them.

 

[GTOM]

Well, military electronics recently is recently 20 years behind civilian. Especially in US where reliability-driven review system resulted in critical delays in fielding modern tech. Accident in 2011 prove exactly this fact.
For more relevant data, you should look onto difficulties law enforcement have recently warding off amateur drones from airports. Or mass use of drones in Syrian civil war. Russians in Hmeimin were unable to reliably jam incoming Idlib-made drones, and resorted to shooting them.

I think send jammer drones between them and stronger microwave weapons could solve many problems.

 

[essenmein]

Modern electronics has grown pretty EMP and jamming resistant, thanks to ever increasing deluge of background wireless networks, and reduced size of electrial parts. Current jammers (as in 2019) are barely catching up with commlink standards developed in 1995. And i suspect the "jammer lag" is still increasing.

Yes and no, while in testing (at least in automotive) does require a lot of immunity testing, they are all at shall we say "reasonable levels" that you might expect in a normal operating environment. EG BCI (bulk current injection), is a way of testing immunity to induced RF disturbances. This is quite difficult to pass esp at the more extreme levels. Which means off course, yes, the circuits are immune to some level, but there is a limit, exceed that and things start to seriously miss-behave. I suspect "civilian" jammers sold to the public are (quite rightly) limited in power by various regulations. In war time such limitations would not exist.

Take as an example:
My friends and I built a 10kW tesla coil powered by a stack of paralleled neon sign transformers (all the same model) while at university as a side project (in the good old days pre 9-11 when things weren't that nutty with respect to "mad science" projects!). The secondary coil was ~1.2m long and based on the free arc length in air (~1.5m) we were at maybe half a MV on the output. It would do more but then then the streamers just hit the strike rail on the primary and that's not near as cool. The electric field that generated would allow me to shock my buddy by just standing behind him. We'd have to unplug the automatic garage door opener because it would randomly open the door other wise. Unbeknownst to us this tesla coil was spewing out enormous amounts of RF garbage.

We would run this a few nights a week after university and play, then go home. A few months later, after university had ended for the year and buddy moved out of that house, we learned that the radio police had been searching for the jamming source that oddly on some nights of the week would wipe out all TV/Radio/Cell service in a several block radius from about 5:30pm till around 7...

 

[trurle]

We'd have to unplug the automatic garage door opener because it would randomly open the door other wise. Unbeknownst to us this tesla coil was spewing out enormous amounts of RF garbage.
We would run this a few nights a week after university and play, then go home. A few months later, after university had ended for the year and buddy moved out of that house, we learned that the radio police had been searching for the jamming source that oddly on some nights of the week would wipe out all TV/Radio/Cell service in a several block radius from about 5:30pm till around 7...

An interesting report. I wonder if that time cell phone service in area was still 2G? I think you can jam 2G (GSM) network with a reasonable spark-gap transmitter. Most of newer standards are simply not in the spar-gap band (roughly up to 1 GHz).

 

[essenmein]

An interesting report. I wonder if that time cell phone service in area was still 2G? I think you can jam 2G (GSM) network with a reasonable spark-gap transmitter. Most of newer standards are simply not in the spar-gap band (roughly up to 1 GHz).

Never really thought about the EM band width of an arc, I always assumed it was pretty broad band since my arc welder makes dangerous levels of UV! Maybe different energy/current/voltage relation ships create different bands? duno.

The tesla coil was really more about power than the actual source of the EM, a ground based high power transmitter could easily overwhelm receivers if transmitting in the right range, and with enough power probably cause damage to circuits.

Re teh phones, this was late 90's, definitely had early GSM couldn't tell you what gen.

 

[trurle]

Never really thought about the EM band width of an arc, I always assumed it was pretty broad band since my arc welder makes dangerous levels of UV! Maybe different energy/current/voltage relation ships create different bands? duno.

The tesla coil was really more about power than the actual source of the EM, a ground based high power transmitter could easily overwhelm receivers if transmitting in the right range, and with enough power probably cause damage to circuits.

Re teh phones, this was late 90's, definitely had early GSM couldn't tell you what gen.

Spark gap do extra-thermal emission at RF; most of RF generation of spark is due current instabilities ans tails off at about 400-500 MHz. The cutoff frequency is actually have to do with air pressure, not feeding voltage/current. Lower harmonics can extend the jamming band roughly to 1.3 GHz.

Regarding "brute force" jamming, it do not work well with LTE (4G) commlinks. LTE tolerate by standard 0.3 mW of in-band interference per antenna. With typical 5 cm patch antennas, tolerance is 0.12 W/m2. With typical heavy-track based military jammer having 30 kW output, the effective (omnidirectional) jamming is achieved at distance 140 meters. Or may be even 5-15m meters if drone use a MIMO antenna array. This number shows it is pretty difficult to jam a large swarm of drones.

 

[GTOM]

Spark gap do extra-thermal emission at RF; most of RF generation of spark is due current instabilities ans tails off at about 400-500 MHz. The cutoff frequency is actually have to do with air pressure, not feeding voltage/current. Lower harmonics can extend the jamming band roughly to 1.3 GHz.

Regarding "brute force" jamming, it do not work well with LTE (4G) commlinks. LTE tolerate by standard 0.3 mW of in-band interference per antenna. With typical 5 cm patch antennas, tolerance is 0.12 W/m2. With typical heavy-track based military jammer having 30 kW output, the effective (omnidirectional) jamming is achieved at distance 140 meters. Or may be even 5-15m meters if drone use a MIMO antenna array. This number shows it is pretty difficult to jam a large swarm of drones.

There are already jammer rifles directed at drones.

 

[trurle]

There are already jammer rifles directed at drones.

Yes. With them you can temporarily disable one drone at time at few hundred meters distance. Well, if you consider this device effective, i have no objections.

 

[essenmein]

Spark gap do extra-thermal emission at RF; most of RF generation of spark is due current instabilities ans tails off at about 400-500 MHz. The cutoff frequency is actually have to do with air pressure, not feeding voltage/current. Lower harmonics can extend the jamming band roughly to 1.3 GHz.

Regarding "brute force" jamming, it do not work well with LTE (4G) commlinks. LTE tolerate by standard 0.3 mW of in-band interference per antenna. With typical 5 cm patch antennas, tolerance is 0.12 W/m2. With typical heavy-track based military jammer having 30 kW output, the effective (omnidirectional) jamming is achieved at distance 140 meters. Or may be even 5-15m meters if drone use a MIMO antenna array. This number shows it is pretty difficult to jam a large swarm of drones.

If you take out the omni directional aspect, maybe have a beam that sweeps, similar to a radar, or more a more focused beam that covers a portion of a hemisphere. I think given power/weight limits in smaller drones they are unlikely to be super sonic for example, so they are not going to cover a lot of ground very quickly. But a question would be what happens when the jamming signal is removed, if its not strong enough to damage the drone, it will likely just resume what it was doing.

You'd want to probably combine this with some sort of detection/aiming so swarms of drones can be detected on approach and brought down with a powerful truck mounted micro wave "flash light" rather than having this thing constantly jamming everything, including your own transmissions.

As a side note, I would have thought a vehicle based jammer would have a bit more power than 30kW!

 

[essenmein]

Interesting video. Latter on you get a ground based view, they certainly announce their arrival acoustically!

 

[Janus]

Depends on how sophisticated and ruthless the AI he is trying to hack is does it not?

Hacking requires a link does it not? And upon a hacker being detected, I am certain the AI would be sending whatever appropriate level of force is required to 'neutralize' the threat.

Star Trek makes me laugh. Sending in away times via teleport in harm's way often when they could be sending drones.

I guess they did not foresee drone technology as being huge in the future.

Wouldn't have that been exciting television? Watching a bunch of guys sitting around, sipping coffee while operating drones.
The tension and drama from an action adventure show comes from placing your characters in peril. Even the transporter, a invention to allow a quick way of getting characters into the action was a two-edged sword. It could pull them out of trouble just as easily as it put them there. Thus so many plots had to include a reason why they could not use the transporter to return to the ship.