Exploring the Plausibility of SF Energy Shield Alternatives

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The discussion explores the feasibility of alternatives to science fiction energy shields for spacecraft, highlighting that current materials cannot withstand high-velocity impacts. Whipple shields are noted for their effectiveness against micrometeoroids, while concepts like mini-robot clouds and plasma windows are proposed but deemed impractical with existing technology. The conversation emphasizes that real-world spacecraft would likely rely on less active defenses and prioritize offensive capabilities due to energy and mass limitations. Ultimately, the consensus is that true energy shields, as depicted in sci-fi, remain unattainable without significant technological breakthroughs. The dialogue concludes that any protective measures would likely serve more as deterrents than as effective shields against advanced threats.
  • #31
trurle said:
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.
 
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  • #32
GTOM said:
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.
 
  • #33
trurle said:
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!
 
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Likes trurle and GTOM
  • #34
Interesting video. Latter on you get a ground based view, they certainly announce their arrival acoustically!

 
  • #35
Bab5space said:
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.
 
  • #36
Janus said:
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.

As there are several ways to cook an egg, there are several ways to create tension and danger for characters if that's what you want.

Sabotage? Traitors? Enemy attack on the control ship? There is still plenty tension to go around if that's what you want.

By the time our heroes are marooned on an alien world they are losing anyway, so it won't be the norm as I do not write Star Trek.
 
  • #37
essenmein said:
As a side note, I would have thought a vehicle based jammer would have a bit more power than 30kW!
Military guys would also like to have more power. Unfortunately, 30 kW jammer is what possible on a single 8x8 truck with current tech.
 
  • #38
Been a few years but, when RAF were practising 'Time over Target' attacks prior to Iraq 1 or 2, their jets' late-morning pass over our local airport, with radars & jammers at 'full military power', knocked out lots of our lab equipment.

Having a dozen high-end data collection systems go 'graaak' and re-boot mid-run was seriously bad news. We could not just resume, we had to cold-start, re-do pre-run suitability checks. One afternoon, the RAF made a second pass and everything went down again. Our late shift kindly completed the pre-run checks, launched half the batch analyses planned...
 

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