Slashdot Mirror
Hypersonic Radio Black-Out Problem Solved
KentuckyFC writes "Russian physicists have come up with a new way to communicate with hypersonic vehicles surrounded by a sheath of plasma. Ordinarily, this plasma absorbs and reflects radio waves at communications frequencies, leading to a few tense minutes during the re-entry of manned vehicles such as the shuttle. However, the problem is even more acute for military vehicles such as ballistic missiles and hypersonic planes. Radio blackout prevents these vehicles from accessing GPS signals for navigation and does not allow them to be re-targeted or disarmed at the last minute. But a group of Russian physicists say they can get around this problem by turning the entire plasma sheath into a radio antenna. They point out that any incoming signal is both reflected and absorbed by the plasma. The reflected signal is lost but the absorbed energy sets up a resonating electric field at a certain depth within the plasma. In effect, this layer within the plasma acts like a radio antenna, receiving the signal. However, the signal cannot travel further through the plasma to the spacecraft."
Is this PC? Maybe use "slave out"? What do you think, Linda?
The SNR and BER of that scheme are going to suck.
Until the creation of the Tracking and Data Relay Satellite System, the Space Shuttle would, like Gemini, Mercury, Apollo, and others, endure a 30 minute long communications blackout before landing. However, the Shuttle can communicate with a Tracking and Data Relay Satellite during re-entry. This is because the shape of the Shuttle creates a "hole" in the ionized air envelope, at the tail end of the craft, through which it can communicate upwards to a satellite in orbit and thence to a ground station.
Damn Obama, wasting our taxe... oh? Whats that? Russian Scientists you say?
http://www.freepatentsonline.com/3758862.html
(except it's patented)...
The space program has been used for military research and military purposes. There's quite a bit of overlap between sending a man to orbit and sending a missile to orbit. That GPS satellite can be used to get you from point A to B or that ballistic missile to Moscow. Satellite cameras to search the stars aren't altogether different from spy satellites to search the ground. Maybe some of the experience they've gotten from, say, the Mars rovers was useful in building the various military drones they have now.
I think it's fair to say that the military would find ways to use civilian technology in relevant fields, and space exploration has some pretty big overlaps.
SSC
China testing the J-20. Good thing Obama didn't cancel F-22 produ.... oh, wait.
I read the full summary. The last sentence that the signal cannot travel into the craft from the plasma. How is that solved?
The cause of, and solution to, all technological problems in the 23rd century.
since we have a 168 of them, I don't really see a problem with the project not being funded. Add to this its 20 year old tech, and not fighters are moving away from having a pilot in the craft, it was a good decision. And I love the things.
FIY: being canceled, and being no longer funded are different things.
.
The Kruger Dunning explains most post on
At the end of TFA they give the original reference, a paper preprinted in 2007. One way to tell if this holds water is to see if other research groups have done follow-ups in the intervening three years.
Just one glitch-- you can transmit with a plasma antenna, but you can't receive worth a darn.
You see the plasma is a bunch of random electrical discharges and accelerated particles, which put out a strong wideband noise, quite a few orders of magnitude stronger than any signal you might wish to receive.
And what's the rush? Re-entry plasma is time-limited to just a handful of minutes. Astronauts should be able to get along without Wi-Fi for that long.
You're really limit in your thinking.
Technology is constantly developed to make killing more precise; which means LESS killing.
And there are a hell of a lot of spin-offs that are used in civilian markets. I don't see why you have created some sort of demarcation between killing tech and non killing tech. there is just tech that is used. The same tech is often used for killing as it used for non killing.
The Kruger Dunning explains most post on
...or that ballistic missile to Moscow
If you mean Moscow, Russia, then "to within 200 miles of Moscow" would be more accurate. Getting closer would be very problematic for a ballistic missile, unless A-135 has been sold for scrap like so much else in Russia.
I'm a military contractor, you insensitive clod.
---
ECHELON is a government program to find words like bomb, jihad, plutonium, assassinate, and anarchy.
That the tech is 20 years old is irrelevant when everybody else's is too. Further, there are NO operational interceptor drones, and it will be decades before one is more capable than an F-22. The demands of an interceptor are completely different from the surveillance and light ground attack roles that drones are filling now.
The end result of a cancelled program and a defunded program is the same: no more aircraft will be produced.
I support the Slashcott and will not be reading or commenting from 2/10/14 to 2/17/14. Beta is steaming pile of dog shit
Well, I read the full introduction of the paper, and the conclusion, skipping only the detailed plasma physics models & calculations. They do mention the strategy of putting an antenna through the plasma which can last as long as one fuel tank before it ablates, but they instead propose that (more elegantly) a small commercially-available 3 kW high frequency klystron amplifier (a lot less power than the radar) be placed at the surface of the aircraft, where it will disrupt a very small region of the plasma in a manner that will scatter ~.7 - 2% of the original incoming signal (which will resonates in a layer of the plasma) back to the aircraft; that is enough power for a 5 m. antenna and a commercially-available high sensitivity GPS receiver to pick it up. There is an analogous explanation for outgoing signals. They account for quite a few confounding plasma effects, acknowledge that there are some others that can't be modeled so clearly (or maybe they didn't think of), but predict that getting the system to work would be a not-so-difficult engineering challenge.
My first thought was, "Boy, I hope all the space opera authors read this preprint: no more signal attenuation from the plasma engines in the atmosphere!" Now there is one more area in which reality is exceeding a certain segment of--rather soft--science fiction (that I am only familiar with--AHEM--because of Baen's visionary no-DRM any-format ebook policy).
iirc, the F22 project was defunded so that they could move the money to the F35 project, which seems to be progressing nicely...
"You're really limit in your thinking. Technology is constantly developed to make killing more precise; which means LESS killing."
Ah, the only person _limited_ (good spelling, genius) in their thinking is you. How many people die in violent conflict has a lot more to do, for my money, with the political will of national leaders to start wars and kill people. Drone missiles, for example, may be more precise than carpet bombing, but that just means an expansion of targets which formerly would have been off-limits, each with their own (admittedly smaller) set of collateral damage.
Look at how many people have died in Pakistan from drone missile strikes at apartments. It's like 10-12 deaths an attack, usually aimed at one person (the 'target'). Or wedding parties in Afghanistan. Or the fact that our whole fucking invasion of Iraq (with hundreds of thousands of civilian casualties) was possible in part b/c Americans like you were sold on how our technologically sophisticated supersoldiers can kill the bad guy and save the baby while feeding the hungry. It's almost like you think the tomahawks are dropping food aid out a chute on the way to the target.
The value of our military R&D budget is a different question. I'm just pointing out how fatally flawed your argument is.
"Never mind that space exploration can produce tons more spinoffs per dollar. "
Can't. Never has, never will. Space has always been a PR stunt to hide war technologies, mixed in with some saber-rattiling. The geeks with their wide-eyed wild fantasies and delusions of orbital factories and Moon mining are so far away from being practical and economical, it's laughable. It will simply NEVER EVER work, EVER. As long we have chemical reactions, oil and rocket engines. See that changing anytime soon? Yeah, didn't think so.
What I find most interesting is what the article didn't say. Oh, there is a plasma surrounding hypersonic vehicles, thats true. But, dear reader, there is *also* a plasma around military aircraft that use plasma to jam radar. Its not just the oblique features of the aircraft that contribute to a low radar signature (or the turbine intake that contributes to a high radar signature). Military aircraft have used RAM (radar absorbing material) in the paint of these aircraft --basically the paint acts like very small radar absorbing cavities that allows radar in, and then it bounces around in the paint, slightly heating it, and not reflecting it. But besides these two methods of jamming radar, you can put a plasma (artificial St. Elmos Fire), around parts of the aircraft with a high signature, and as the article states, the EM radiation that is the radar pulse can't get through it, and can't reflect off it. So you are invisible. Now this article and the technology it describes solves re-entry radio blackouts, but also the military kind. Thanks for reading....
The A-135 can only really defend Moscow against a single warhead, or just a handful at the most. The radar system itself is susceptible to suppression, seeing as how there's only one pillbox providing support for the interceptors. Only the first wave defense is likely to be effective, and there's only 32 of those missiles, which would hardly put much of a dent into a serious ballistic missile attack, considering the number of decoys and warheads implemented in modern missile systems. The second wave defenses, while more numerous, are non-nuclear now and probably wouldn't intercept much of anything. They were designed for nuclear warheads originally, something which of course would irradiate much of Moscow anyway. There may still be some nuclear warheads in the second wave, but stopping the enemy missiles from striking your city isn't all that great if your own missiles kill you anyway.
This is all, of course, predicated on the idea that the A-135 is still operational. There's some evidence that it's not, really, and only used for "tests" whenever the US starts thinking about upgrading their own ABM systems.
-mrxak
Onions Will Kill You
And, indeed, that much of what we now consider to be civilian technology was developed initially for military applications. The internet, for example, was funded by DARPA. So was GPS -- can't lay my hands on a good list, but I'm sure it's quite extensive.
Lost at C:>. Found at C.
iirc, the F22 project was defunded so that they could move the money to the F35 project, which seems to be progressing nicely...
You must work in Marketing. "Progressing Nicely?"
Faster! Faster! Faster would be better!
You can't have an advanced fighter jet without a pilot in the craft. Remote-control aircraft work fine for fighting stone-age enemies on the ground in backwards countries who have no ability to jam your radio signals, but that won't work when fighting someone with the same level of technology, in aerial combat.
Basically, we're giving up on the ability to fight anyone with similar technology, and concentrating only on fighting insurgents on the ground.
Not marketing, just insufficient information. Thanks for the pointer :)
You don't need to send radio signals to your drone if you have a good enough computer/smart enough software on board.
The standard argument against being able to remotely disarm missiles has been that including such a mechanism opens the door for the enemy potentially figuring out how to do it - it's not about the ability to communicate.
#DeleteChrome
Technology is constantly developed to make killing more precise; which means LESS killing.
And there are a hell of a lot of spin-offs that are used in civilian markets. I don't see why you have created some sort of demarcation between killing tech and non killing tech. there is just tech that is used. The same tech is often used for killing as it used for non killing.
Gatling gun, A-bomb, H-bomb, Napalm, MOAB... precise enough for government work I guess.
Set your phasers on "funky"!
iirc, the F22 project was defunded so that they could move the money to the F35 project, which seems to be progressing nicely...
You must work in Marketing. "Progressing Nicely?"
Probably more like a PR spin-doctor.
The mind conceives, the body achieves, the spirit manifests.
Don't worry. Israel has your back.
Do you or your partner snore? - Visit www.snoring.com.au
Huh? Computers aren't artificially intelligent yet.
You're really limit in your thinking.
Technology is constantly developed to make killing more precise; which means LESS killing.
you mean like the hydrogen bomb? the one which can precisely destroy a WHOLE city? technological progress does not automatically mean more precise killing, sometimes it also enables mass killing.
Wealth is the gift that keeps on giving.
The geeks with their wide-eyed wild fantasies and delusions of 8GB RAM and Quad Core Processors are so far away from being practical and economical, it's laughable. It will simply NEVER EVER work, EVER.
Wealth is the gift that keeps on giving.
Huh? Computers aren't artificially intelligent yet.
Have you played any flight combat simulators? It's not hard to get the computer to whip a human's ass. The hard part is getting enough data into the computer to allow it to make "intelligent" decisions.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
If you can save enough money in production by removing life support and in operation by reducing personnel, it's conceivable that I'm fielding 10 drones for each of your pilots. And my pilots gain experience even when their craft is destroyed. In a prolonged, real shooting war these things add up.
Of course, if it ever comes to that we'll see both sides fielding mixed squadrons so they get the best of both, at least for the foreseeable future.
Remote controlled drone vs. live pilot in the seat I concede that for now the pilot will likely win out.
what if it's 3 drones to one live pilot
what if it's 7
what about ten?
every day http://en.wikipedia.org/wiki/Special:Random
Y...Basically, we're giving up on the ability to fight anyone with similar technology, and concentrating only on fighting insurgents on the ground.
Well, actually, that at least sounds consistent. Since MOST of our weapons are produced by private corporations -- and THEY have weapons plants in some of those "Potential Enemy" countries -- just shooting people too poor to jam your radar and PRETENDING to have air craft carriers for some other reason than to spend lots of money on these same corporations seems to be working out great for all the Players involved.
>> If you can find a way to JUST shoot poor people, than that would be a VERY smart bomb. GE would hire you in a second.
>>"ad space available -- low rates!!!"
If it ACTUALLY gets into a shooting war between some country like the USA and China -- FIRST, all the hunter-killer satellites that NOBODY has in space will go out and attack other satellites and GPS systems. IF any side starts to win THAT war, one bomb from either country can render Space un-usable for years until a billion fragments stop traveling through it at supersonic speed.
THEN, millions of tiny bug-like robots, that just seek out humans will be sent by hyper-sonic torpedoes -- ones that can travel in their own shockwave underneath the ocean and avoid all radar and anti-missile systems we currently have.
No nukes of course, until Rich people can get those bunkers built -- in ten years, well, the surface of the planet could just turn to glass. No need for fighter jets or drones then.
>> BUT, if the rich people don't have bunkers that they can comfortably live in for 3 generations, this future war will be all electronic.
IF we start winning, China will then send out a RADIO KILL SIGNAL, and all those chips we bought from them will stop working -- including that super cheap Microwave Oven you have at home. So when it gets to this point, you will still be unaware there even was a war, but all the banks will change to something like "People's Bank of America."
Your blender and microwave, however, will mysteriously all need to be sent back to the manufacturer for repair, and you will pay for that in Yuan.
>>"ad space available -- low rates!!!"
Speaking of windows, look out yours. What do you see? The same houses, roads, cars, planes, clothes, food and oil-powered agriculture that was there since WWII.
There is simply no way, ever, that space is going to pay off. It's OVER. FINISHED.
Space Nutters have had DECADES to show us something, anything. End result? Sweet. Fuck. All.
But hey, don't listen to me. Listen to Dr Stephen Pyne.
CBC Quirks and Quarks
Listen to the "January 8 — Homage to Voyager." episode when it's out. I remember something like "the ISS is not exploring space, it's not even science." when I heard it on the radio today.
But hey, there's more!
http://www.spacedaily.com/news/oped-04y.html
http://findarticles.com/p/articles/mi_m1134/is_9_115/ai_n27050480/?tag=content;col1
Or my favorite:
http://www.cbc.ca/quirks/episode/2009/09/19/tiny-trex-curing-colour-blind-monkeys-walking-on-our-own-two-feet-space-based-solar-power/
Where the scientist is barely holding back from laughing out loud at the outlandish "space-based solar power" projects. Hey, wasn't there one just last year? Where is it now? Oh yeah, oblivion.
We've hit limits in energy sources and propulsion technologies. Rockets take our technology to the outer limits of what's possible with materials. Unless you find new elements in the table of elements, what we have is *it*.
That 747 you saw when you looked out the window? Maiden flight was 1969. Hasn't changed in over four decades. Why? The technology and basic physical reality hasn't changed. It can't. But you think we'll be doing space? Ridiculous.
The fact we have fast computers today on a square inch of silicon doesn't help you move mass around. It's that basic. The fact you don't get that is both sad and terrifying.
@MajorTom: We just started our re-entry...