tag:blogger.com,1999:blog-8150340806781551727.post2738599324960517007..comments2024-03-29T07:43:40.648+00:00Comments on ToughSF: Stealth in Space is Possible IIMatter Beamhttp://www.blogger.com/profile/16721504049578296529noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-8150340806781551727.post-65101922333176102942019-02-15T10:42:27.739+00:002019-02-15T10:42:27.739+00:00How would future decoys be like.
Is it possible ...How would future decoys be like.<br /><br /> Is it possible to make a smart flair that can mimic the electromagnetic signature of a ship. At least for a shot time. The Librarianhttps://www.blogger.com/profile/01646848861149556379noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-43697197592223463132018-05-10T19:53:33.570+01:002018-05-10T19:53:33.570+01:00It is a mistake. It should have been solid hydroge...It is a mistake. It should have been solid hydrogen. <br />Here is the phase diagram: https://www.researchgate.net/profile/Andreas_Zuettel/publication/8618603/figure/fig1/AS:277689450680341@1443217732712/Primitive-phase-diagram-for-hydrogen-Liquid-hydrogen-only-exists-between-the-solid-line.png<br /><br />Between 4K and 20K, at a pressure of 1 atmosphere, the hydrogen transitions from solid to liquid. Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-37370851321179011542018-05-10T19:35:02.780+01:002018-05-10T19:35:02.780+01:00"A liquid hydrogen reserve at 4 K"
I not..."A liquid hydrogen reserve at 4 K"<br />I note that wikipedia gives 13.99 K as the freezing/melting point of hydrogen.<br />What did you intend to type & does the change affect the amount of heat absorbed?Jim Baerghttps://www.blogger.com/profile/03182949391365921637noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-22059813940549185582016-05-19T21:00:37.234+01:002016-05-19T21:00:37.234+01:00Thank you for pointing it out, I'll make the n...Thank you for pointing it out, I'll make the necessary corrections.Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-91140286430503217362016-05-19T17:27:39.052+01:002016-05-19T17:27:39.052+01:00Small correction:
The image labeled "The Kep...Small correction: <br />The image labeled "The Kepler telescope sitting on its 5-layer sunshield" – I believe it is actually the James Webb Space Telescope:<br /><br />https://en.wikipedia.org/wiki/James_Webb_Space_Telescopeafrodrihttps://www.blogger.com/profile/08285687249830093968noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-41982320141427656862016-03-27T19:00:54.758+01:002016-03-27T19:00:54.758+01:00So, basically using them doesn't make sense. I...So, basically using them doesn't make sense. I really like this cold plate design, spaceship looks like Knight hiding himself behind shield :)<br />I wonder if it will be significantly harder to find enemy ships if the space system is full of other ships, like trade, passenger and transport. What do you think about this not really stealth tech, but stealth method of approaching?MrAndersonhttps://www.blogger.com/profile/16241592537760863429noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-17706327651375480722016-03-27T02:00:50.087+01:002016-03-27T02:00:50.087+01:00I see three issues with 'cold plasma' radi...I see three issues with 'cold plasma' radiators:<br /><br />-cold objects emit less, so you need huge areas to get rid of waste heat. The hotter the radiator, the smaller and lighter it is.<br /><br />-plasma would emit heat in all directions. This might not be useful if you are trying to emit away from the positions of likely targets.<br /><br />-plasma would have to be controlled through magnetic systems, which increase waste heat heat. Also, it uncertain whether they can be carried along under acceleration...Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-8461426508172652642016-03-26T23:23:23.733+00:002016-03-26T23:23:23.733+00:00I ve got question, is it possible to make radiator...I ve got question, is it possible to make radiator from cold plasma? I don't know if cold plasmas can be cold enough to be used as radiator, but... This could be like improvement over charged dust and droplets, I think. MrAndersonhttps://www.blogger.com/profile/16241592537760863429noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-77126250893663808512016-03-25T17:30:10.577+00:002016-03-25T17:30:10.577+00:00Reducing the temperature a lot will require a lot ...Reducing the temperature a lot will require a lot of work (both in the figurative and physical sense), and in the process generate even more heat that will need to be disposed of - not to mention the extra mass required for the refrigeration and insulation.<br /><br />A specularly reflective surface will be hard to detect with active sensors, because the detection and ranging pulse will be reflected specularly - which will usually be in a direction away from the sensor looking for the reflected pulse. So unless you are exactly face-on to the guy looking for you, his pulses just get re-directed out into the void of space someplace where no-one will ever see them again.<br /><br />This assumes far infrared lidar, of course. For radar, you need to worry about resonances where bits of your structure act like antennae to enhance the scattering, diffraction from specular scattering, interactions with the edges of the cold plate, and such. Even then, the reflective surface gives something of an advantage by enhancing specular reflection, a principle exploited by current stealth aircraft. A vantablack surface, for example, might just get you diffuse reflection of microwave pulses which are easily seen (has anyone even studied the microwave properties of vantablack?).Lukehttps://www.blogger.com/profile/09617890536562434320noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-67203259870747223172016-03-25T16:00:16.550+00:002016-03-25T16:00:16.550+00:00I understand that something like aluminized mylar ...I understand that something like aluminized mylar with emissity of 0.03 would be great at reducing radiations, but won't the same effect be achieved by cooling a super-emissive material like Vantablack to even lower temperatures?<br /><br />The second solution requires a larger cryogenic cooling system, but at least you het the side effect of defeating active detection.Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.comtag:blogger.com,1999:blog-8150340806781551727.post-79354130974073231452016-03-25T02:31:23.105+00:002016-03-25T02:31:23.105+00:00Note that for the cold plate, it would be very use...Note that for the cold plate, it would be very useful to have the layer facing the enemy have as low of an emissivity as possible in the infrared. Highly polished gold or aluminum, for example, might have an emissivity of 0.05 across the relevant infrared wavelengths used for detection. This not only cuts down on your own thermal emissions, but reflects the thermal emissions of space making you look like just empty space.<br /><br />It is also useful to note that the largest source of infrared background is not the CMB, but zodiacal dust heated by sunlight. This makes hiding in the infrared zodiacal glow around a star slightly easier (but not too much easier - you're still looking at multi-AU detection distances for realistic scenarios).Lukehttps://www.blogger.com/profile/09617890536562434320noreply@blogger.com