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US Air Force Wants To Plasma Bomb The Sky To Improve Radio Communication (newscientist.com)
An anonymous reader quotes a report from New Scientist: [The U.S. Air Force has plans to improve radio communication over long distances by detonating plasma bombs in the upper atmosphere using a fleet of micro satellites. It's not the first time we've tried to improve radio communication by tinkering with the ionosphere. HAARP, the High Frequency Active Auroral Research Program in Alaska, stimulates the ionosphere with radiation from ground-based antennas to produce radio-reflecting plasma.] Now the USAF wants to do this more efficiently, with tiny satellites -- such as CubeSats -- carrying large volumes of ionized gas directly into the ionosphere. As well as increasing the range of radio signals, the USAF says it wants to smooth out the effects of solar winds, which can knock out GPS, and also investigate the possibility of blocking communication from enemy satellites. [There are at least two major challenges. One is building a plasma generator small enough to fit on a CubeSat -- roughly 10 centimeters cubed. Then there's the problem of controlling exactly how the plasma will disperse once it is released. The USAF has awarded three contracts to teams who are sketching out ways to tackle the approach. The best proposal will be selected for a second phase in which plasma generators will be tested in vacuum chambers and exploratory space flights.]
Bearing in mind that public funds are involved here, I'm struggling to understand why improving radio communications using "plasma bomb" satellites is such a great idea when satellites already do such a great job improving radio communications. In other words, we have vast numbers of artificial ionosphere "bouncers" already orbiting our planet, and we can also have high altitude tethered balloons and long duration airborne aircraft (perhaps solar electric) that the likes of Google and Facebook are working on -- and with much less investment than even one copy of the some of the aircraft the U.S. Air Force flies. We already know how to bounce radio signals all around the globe, and it's already cheap, reliable, and secure. So what's the "value add" here that merits substantial public investment? Anybody have any ideas?
Maybe they know something we don't. This setup will allow for an alternate comm path should the current satellites and cables become unavailable. Hams and the government would still be able to communicate. Assuming an EMP event, then most of the hams would be out of business and only the govt would still be able to communicate with the equipment that we paid for them to harden... Just sayin'
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This is excellent news if true. Short wave broadcast radio has been in decline all my life and radio hams have increasingly turned to the more exciting fields of digital communications and microwave. If it livens up the bands again then I am all for it. I assume that the objective is to learn how to thicken it up enough to locally cut off communications from space thereby killing the enemies communications network. The only downside might be disruption of radio astronomy, but we should be doing that from the moon anyway.
Facts are history now plebs have politics for religion on social media.
There aren't enough cables. The Internet is such absurdly critical infrastructure, and we have only a handful of cables even for the most-dense connections. While the Internet routes around damage efficiently, the amount of time it takes to route around damage is longer than would be desired these days (where an assumption of failure is the norm for critical applications), and a small reduction in capacity could easily be catastrophic.
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Given the size of ionosphere, the ionisation density and recombination rate, and the size of a micro satellite this project looks like trying to deplete Lake Tahoe with a teaspoon...
The last time the USA fucked around with the ionosphere was a bit of a disaster. Please do not do this again; just leave it alone. Wired article. They are also an object group on stuffin.space.
I am sure that radio astronomers would agree with you on that one, as well as oppose this 'plan'
After all, while such plasma will help reflect internal signals, it will also help block external ones,
including signals to most other satellites - seems like a winner (although the effects are very
frequency dependent).
I suspect this is someone in charge of old systems wanting to get more funding for their little
fiefdom without looking at the modernisation of communications, where ionosphere bounce is
rapidly becoming an outdated method.
That and the fact that suggesting military NOT spend big money on any idea they come up with
if bordering on treason these days, right?
Mind you, the HAARP conspiracy crowd will LOVE it, make them even more paranoid ;)
where ionosphere bounce is rapidly becoming an outdated method.
Hate to break it to you, buddy, but it's still the only infrastructure-free method of global communication, which means it's just as effective as when it was first discovered. Your massive satellite/cable network is great for when everyone's playing nice and is OK with a small group of people having control of almost all the information flow, and your ionospheric propagation remains good otherwise.
tl;dr Progress is good, but should not be misidentified nor misinterpreted. 2.
This said, changing propagation characteristics of the ionosphere seems to be a crap idea. Or, rather, it's an obvious idea with consequences that haven't really been thought through.
One of my hobbies is critiquing unpublished authors, and there's a certain group of writers who write post-apocalyptic "gun sci-fi" where it's more important to get the minutiae of gun technology right than it is to get the science right. Their science tends to come straight from other stories. The EMP scenario is sufficiently popular that I decided to spend a weekend afternoon doing the research into EMP that they should have.
EMP is not magic, like in the movies or on TV. It works by physical effects that require energy to be propagated to the affected device, which can be shielded and otherwise radiation hardened. You would need a massive attack that saturates all of near space to take out all satellites from geosynchronous orbits down to LEO. Terrestrial effects are amplified by interaction with the Earth's atmosphere and magnetic field, but even so the kind of blanket destruction of electronics we see in TV sci-fi would require many, many warheads. Many small warheads work better than a few (or usually ONE in the stories I read).
So an attack on communication satellites would tend to be targeted at individual satellites or groups of satellites. Taking out all LEO satellites (assuming they can't be shielded) would require an attack similar to blanketing most of the surface of the Earth.
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Eventually China will surpass the US in both economic activity, and probably, military spending. You will one day look back upon US hegemony with nostalgia. As counterproductive and clumsy as US foreign policy is, it rarely includes expansion or annexation.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
It depends on what point in the solar cycle, but the higher HF bands from ~14-15MHz up through 30MHz are far better during the day for skip due to D-layer and E-layer ionization and also more readily absorbs lower frequencies. At night, ~10MHz and lower works because there is still ionization in the F-layer which is more amenable to those frequencies, and why AM has to typically reduce power. Bear in mind that AM is technically an MF band (0.3-3MHz), which doesn't quite follow the same skywave propagation rules so strictly for a number of reasons such as auroral zone, ducting, and electron gyrofrequency that don't affect HF quite as severely.
You can still get near-vertical incidence skywave propagation during the day on the lower HF bands, but these are only good for a few hundred miles and can be subject to a higher than normal noise floor in the summer due to phenomena such as regional lightning.
I thought Solar UV deionized the skip layer during the day, which is why AM band signals travel farther at night?
No, solar UV ionizes the skip layer during the day down to lower altitudes, leading to refraction of AM band signals from those lower altitudes back to the ground closer to the transmitter than they would at night. At night, the ionized layer is higher, the refraction takes place at higher altitudes, so the signal hits the ground farther away.
There is another effect, too: The higher ionization during the day also leads to increased absorption (attenuation) of the AM band signals at even lower levels of the ionosphere (the D layer) than those at which they are refracted. The D layer disappears at sunset, so absorption by this cause goes away, increasing the received signal strength at distant locations.
The above behavior is for the AM broadcast band (~1 MHz). Above around 10-13 MHz, the situation reverses; during the day, these higher frequencies refract from layers at higher altitudes and suffer less from absorption (the absorption goes as an inverse square of the frequency), so they travel great distances, while at night, there is insufficient ionization to refract the signals back to ground, so they continue out into space and are lost. And above around 20-50 MHz, depending on the state of the sunspot cycle, there is insufficient ionization even during the day to refract the signals back to ground, so one has to resort to secondary mechanisms (e.g., ionization trails of meteors) for long-distance propagation.
Typically, typically. The above is a gross generalization: The effects of the ionosphere on radio waves depends on their frequency, their polarization, their direction and location relative to the geomagnetic equator, the time of day, the month of the year, the status of the sunspot cycle (solar wind), the magnitude of the Earth's magnetic field, the magnitude and direction of the magnetic field in interplanetary space, and eleventeen other factors. Radio propagation prediction software (e.g., VOACAP) deals in probabilities, not certainties.
They think they're looking forward to it, but the proof of the pudding is in the tasting and I can guarantee the Chinese hegemon won't taste so good.
In any case, just having a powerful economy or military isn't a free ticket to global domination, they'd need to work for it and something tells me they wouldn't be unopposed.
So let me get this straight: We all have to worry about Hairspray, Cow Farts, and every other perceived man-made cause of "Climate Change" (f/k/a "Global Warming"); but now we want to intentionally "pollute" the ionosphere?
What could possibly go wrong?