Utopia Talk / Politics / New X-Craft: Hopeless Diamond?

Hip Member	Tue Jan 31 09:56:22 Just came across this. Anyone seen it before? I remember reading about how the holy grail of Stealth was the so-called "Hopeless Diamond". It was the dream shape for stealth because it was the ideal shape. If it could be built, with all other stealth tech integrated, it would be almost invisible to radar, and its shape would mean the ultimate in aerodynamics- meaning extreme lift to drag ratios, exceptional range, and supercruise capability. The Hopeless Diamond was the holy grail of stealth, but it was believed to be unbuildable because it was impossible to make it stable, or so I've read. Could this be the reason we don't give a crap about the stealth drone the Iranians have? http://i44.tinypic.com/2ngrcqw.jpg
Hip Member	Tue Jan 31 09:57:41 Here's where I'd read about it, but I thought it was an abandoned project: http://www...ckheed_hopeless_diamond_01.jpg
Isaksson Member	Tue Jan 31 10:01:58 That can't fly... impossible!
Garyd Member	Tue Jan 31 10:05:52 Anything can fly given enough energy. The trick is, of course, to know where it will fly at any given moment.
Hip Member	Tue Jan 31 10:07:06 I think it's because computers have advanced enough that the stability systems can keep it flying.
Garyd Member	Tue Jan 31 10:17:16 Basically yes. Note the designs of most stealth aircraft are intrinsically unstable, that is you can't fly it without a computer. That includes both the B-2 and the F-117 as well as the F-22. This also makes them inherently more maneuvarable than anything other than biplane. Give it a vectored thrust engine and you could likely even beat that.
Billah Member	Tue Jan 31 10:47:34 You guys all know about the x-37 drone shuttle that has been in orbit for something like 300 days? It's the second one and the first was up for 225 days. They are shaped like space shuttles but two of them could fit in the space shuttle's hanger bay. I'm sure they could easily (but VERY expensively) be augmented with stealth technology. http://www.bbc.co.uk/news/science-environment-16423881
Billah Member	Tue Jan 31 10:48:06 http://en.ruvsa.com/gallery/photo/46/
Billah Member	Tue Jan 31 10:51:13 I think the x37b is the shit because if the military could make them larger and mass produce them, and get an efficient way to get them up to speed, then the US would be able to place armies anywhere on earth in less than 1.5 hours.
Isaksson Member	Tue Jan 31 10:52:02 And ofcourse, airplanes are made out of metal, aluminium, and it flies like a boat out of steel float in the ocean. With my iq of forty i could figure that out.
Isaksson Member	Tue Jan 31 10:56:08 And ofcourse, that x-37 billah showed us, is made out of steel to prevent radation to destroy its equipment, and yes, it waights over 100 tons and are driven by diesel. *Smack in my forehead* OFCOURSE
Billah Member	Tue Jan 31 11:18:14 There is also the HTV-2 which they will definitely keep trying for. 2 failures in test flights 6 months ago =( http://www...lider-mach-20-test-flight.html
Sam Adams Member	Tue Jan 31 11:38:51 "I'm sure they could easily (but VERY expensively) be augmented with stealth technology. " there is no stealth in space.
Billah Member	Tue Jan 31 11:42:07 http://www...ct-absorb-broad-spectrum-light You sure?
Sam Adams Member	Tue Jan 31 11:46:44 ya. Its not reflecting other radiation you have to worry about. Its your own radiation emissions that are the problem. Excess heat must be radiated. While in theory you can use chilled mirrors to block your emissions towards a specific target, this requires that you know where all the enemy sensors are and that there are not many of them. For a short time frame you could also store your heat internally, essentially surrounding yourself with chilled mirrors. Any engine burns are utterly impossible to hide.
Garyd Member	Tue Jan 31 15:10:55 Your IR sig is huge in a place where the back ground temp is below zero
Hip Member	Tue Jan 31 16:45:27 Huh? Once a spacecraft is in orbit, it can shut down and go "dark", and it could be invisible- completely. Tracking a blank spot at 30,000 mph is much easier said than done.
Cloud Strife Member	Tue Jan 31 16:52:07 To be fair, if you had a telescope trained on a fighter jet, you could track it too.
Sam Adams Member	Tue Jan 31 16:52:42 Wrong JB. Orbits are very predictable. The spaceship launches, cuts its engines, and reflects its radiation out into deep space, but all the observers know that path it was on. If it tries to get off that path, everyone would see. If your enemy was only on earth then you could say fly to the moon, on the back side of the moon make your burn, where its blocked from earth view, and then put up your reflector pointed towards earth on your way back. You would now be in a very eccentric orbit unknown to earthbound observers.
Billah Member	Tue Jan 31 18:54:10 Wouldn't the engine heat only be detectable from the back??
Billah Member	Tue Jan 31 21:08:55 And I don't think anyone is allowed on the back side of the moon.
Sam Adams Member	Tue Jan 31 21:21:03 "Wouldn't the engine heat only be detectable from the back??" The skin of the spacecraft radiates heat. Heat is radiated by any object. Unless you are REALLY FUCKING COLD(and having low emissivity helps) you are going to radiate quite a lot, and be detectable. It is of course possible to shield part of the spacecraft with chilled mirrors, but again the engine burns are not possible to hide.
Hip Member	Tue Jan 31 21:57:53 For modifying orbital trajectory, chemical rockets are not the only means of propulsion.
Hip Member	Tue Jan 31 22:00:58 And it only takes 3 or 4 degrees at 30k mph to be thousands of miles away from your original trajectory in 24 hours. Trackers and observers would be looking at where they think you should be, and they'd be off by many, many miles.
Cloud Strife Member	Tue Jan 31 23:51:03 Sam has a small idea of what he's talking about, while JB has very little. Mirrors are about the worst way to be stealthy imaginable, no matter how `cold' they are. It is possible for a ship to be stealthy by internally storing heat and cooling its exterior radiations to dark levels. This is nothing more complicated than a heat pump. This is not sustainable as eventually the interior will become too hot. However, the distances you could travel could be very very large, especially since you could siphon heat into an uninhabited section of the ship in question. Mirrors are stupid, because reflection is how we observe all objects in our solar system.
Cloud Strife Member	Tue Jan 31 23:52:04 Why you guys are arguing over whether or not it is reasonable to have invisible space ships, is a different story, and somewhat stupid.
Sam Adams Member	Wed Feb 01 00:47:59 CS perhaps you should tell me whether bad emitter is a good reflector. Oops! It looks like mirrors are actually the way to go. To be sure, it will be a poor emitter in the infrared and a good absorber in radio, but the radio part really is secondary. "chemical rockets are not the only means of propulsion. " do you think there is anything that does not give off heat?
Sam Adams Member	Wed Feb 01 00:48:54 Especially anything that you might shoot out the ass end of your rocket with significant speed?
Billah Member	Wed Feb 01 00:53:24 Ion engines cause heat? http://www...ive-live-a-galaxy-classic.html
Sam Adams Member	Wed Feb 01 01:16:26 yup. You can burn your engines real slow, like some ion engines, and hope the amount of heat is lower than your enemies detection ability. But then your acceleration is tiny, and if the enemy has sensors you don't know about, you emmit radiation in that direction and even your crew compartment stands out like a neon sign. Having non-biological spacecraft control allows you to operate at cooler temperatures. Of course you'll need to reflect the stars light back at the star, not all in random directions, otherwise CS is right, they'll simply see your reflection. So I guess I shouldn't use the quote that "there is no stealth in space", just thats its really difficult, really easy to defeat, and requires almost no acceleration. Stealth would be much easier for defenders... who could be in deep orbits unmoving for centuries, cold and dead, undetected until required.
Cloud Strife Member	Wed Feb 01 01:28:05 `CS perhaps you should tell me whether bad emitter is a good reflector. Oops! It looks like mirrors are actually the way to go. To be sure, it will be a poor emitter in the infrared and a good absorber in radio, but the radio part really is secondary.' Derrrp, I Shine a light on a mirror, I see the light. Hell LIDAR becomes super effective. Bad emitter, good reflector? What the hell is this nonsense. Absorb everything. ITS SPACE.
Cloud Strife Member	Wed Feb 01 01:30:04 Absorb, scatter, deflect, anything but reflect.
Sam Adams Member	Wed Feb 01 01:39:36 good absorbers are good emitters. You REALLY don't want to be a good emitter. At least, not in the enemies direction. So you place a chilled mirror between you and them. Obviously not angled at 90 degrees though, so any lidar pulse deflects into deep space.
Sam Adams Member	Wed Feb 01 01:40:56 "Bad emitter, good reflector? What the hell is this nonsense. " this nonsense is called fundamental physics. You know, how the real world works. I know its hard for you math types to think about such annoying constraints as the laws of physics. :P
Hip Member	Wed Feb 01 07:49:24 Compressed extremely cold inert gas fired at a single short burst, emitted at 90 degrees of your trajectory (or some fraction of 90 degrees) could alter your flight trajectory a couple of degrees, with little or no detectable signature, allowing you to move off course. 24 hours later, you'd be nowhere near the spot your observers expect you to be. BTW, my comments are in reference to a sort of stealth satellite or stealth "base" in orbit, not a stealth space shuttle, which implies much more maneuvering although in theory, small jets of very cold gas could theoretically make it possible to maneuver a stealth shuttle in much the same way.
Hip Member	Wed Feb 01 07:52:03 Interesting article about coldest object in the universe: http://www...st-object-space-unnatural.html
jergul Member	Wed Feb 01 08:08:29 Compressed extremely cold inert gas. Impossible in space Anything compressed at around 0 Kelvin is not longer a gas. In the case of helium, you would have a liquid. Expanding the liquid is entirely possible. Using a heat source and an expansion valve. If you want your burst of gas and that gas is helium, and lets say you limit pressure to 7 MPa. That gives an initial temperature of at least 7 Kelvin, trending towards 0 as pressure and temperature equalizes with surroundings. So a heat signature.
Hip Member	Wed Feb 01 08:13:31 Yes, but far below the threshold of ground-based detection for the volume (of gas req'd) and temperature differentials (relative to background radiation) involved in altering the trajectory of a small object.
Hip Member	Wed Feb 01 08:14:54 Remember, we're not talking about prolonged streams of highly visible gas. We're talking about a short, cold, tiny "puff".
Hip Member	Wed Feb 01 08:17:50 Do you think ground based detectors can see a 2 meter puff of rapidly dissipating helium at 7 degrees? Remember, I'm not arguing that it is technically impossible. I'm simply stating that it is technically difficult to watch the entire sky for variations in temperature this narrow.
jergul Member	Wed Feb 01 08:32:48 You are not grasping the energy requirements. I assume the vehicle is in stable orbit initially. Changing momentum at those velocities needs a huge amount of energy. You need to change momentum to change direction. You would need to heat a lot of helium to do that. Meaning you have a lot of heat to get rid of. The concept you are presenting here is not a good one.
Sam Adams Member	Wed Feb 01 11:50:38 By simple thermodynamics laws you cannot put a lot of force onto your exhaust without a lot a waste heat. Thus, if you intend to try and make large course corrections, you will be seen. If you make very small burns, you might be able to get away with it.
Sam Adams Member	Wed Feb 01 11:53:37 also by the ideal gas law, the pressure available to you from a gas goes down with low temperatures, JB. And if you put gas outside in an inner system, it rapidly heats up due to the star, so you have to be careful about that too.
Cloud Strife Member	Wed Feb 01 11:56:13 `good absorbers are good emitters. You REALLY don't want to be a good emitter. At least, not in the enemies direction. So you place a chilled mirror between you and them. Obviously not angled at 90 degrees though, so any lidar pulse deflects into deep space. ' Cold doesn't EMIT. That's the whole point. OMFG. Jergul - That's why you don't use air conditioning. You use reasonable methods that are used in more intense temperature reduction, like heat pumps. And also, there's always a gravitational signal, so it's always theoretically possible to be detected that way. You paranoid lunatics are too much.
Cloud Strife Member	Wed Feb 01 11:57:21 So on one hand we have JB who believes god knows what. We have Sam who thinks mirrors are somehow relevant and that waste heat is just impossible to control. And we have Jergul who wants to tie an ac unit to his aircraft.
Cloud Strife Member	Wed Feb 01 11:58:00 And all of this for stealth in space, which is a ludicrous concept.
Sam Adams Member	Wed Feb 01 12:06:10 "Cold doesn't EMIT. That's the whole point." 1) yes it does. Unless its absolute 0, which it won't be. 2) to be really cold, you need to not absorb. and something that doesnt absorb much is a reflector. A mirror. give up, CS. Physics>Math.
jergul Member	Wed Feb 01 12:24:03 CS We certainly have CS who is struggling with functional literacy. The concept as presented sucks. I offered no suggestion beyond pointing that out.
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