From: mikkelhaaheim@gmail.com   
      
   Le mercredi 5 octobre 2016 19:51:29 UTC+2, Rick Pikul/Chakat Firepaw a   
   écrit :   
      
   >    
   > Of course, do you know what a cloud of steam released from your ship is?     
   > A nice, bright, source of blackbody radiation, (water is a near-perfect    
   > blackbody).   
      
   Keep in mind that gases do not behave exactly the same way as solid   
   blackbodies.   
      
   > You need to pump heat away from the skin on your cold sides.   
      
   You need a flow of coolant. This in itself is not what is meant by a "heat   
   pump". The coolant has to be colder than the target temperature. A supply of   
   liquid He, cooled to 1°K would work.   
   That said, it will likely be much preferable to use a heat pump to rechill the   
   He, rather than to treat the He as an expendable mass... you would need a hell   
   of a lot of He to absorb all the sunlight energy. So, yes, I am assuming you   
   will be using a    
   heat pump for this.    
   You would not, however, need a heat pump to keep the habitat cool, nor to   
   chill any reactors or thrusters you might have.   
      
      
   >    
   > So you don't need that many sensor locations to get yourself spotted.   
      
   You would need to have enough to be both within sensitivity range, at an angle   
   where the emissions exceed the sensitivity threshold. So, yeah, you are still   
   talking about a lot of platforms.   
      
      
   > Nope, detection relies on radiance.  Unless you can get your exposure to    
   > 0, you are just as noticeable.   
      
   Nonsense. Detection relies on how much energy is getting to the detector, not   
   how much energy is being radiated out. Flat panel emittors present a risk,   
   because you are actually emitting above average energy directly normal to the   
   panel... but at    
   increasing angles of incidence off the normal, the emission falls well below   
   average. At such angles, you need to be MUCH closer to detect the flux.   
      
      
   > I don't think you realize how small the budgets for those more    
   > specialised organisations are.   
      
   NASA's current budget is hovering around 0.4% national budget. This is down   
   from a peak of just over 4%. Scientific research in general is at 3%. Combined   
   military and intelligence (including DARPA research and the NRO) related   
   spending is 54%.   
      
   >    
   > > The   
   > > observation capabilities of WISE and Hubble are FAR more advanced than   
   > > anything the military has to offer.   
   >    
   > Um, I take it you missed the news from a few years ago when the NRO    
   > transferred two of its satellites to NASA.  NASA themselves has said that    
   > the optics are better than Hubble's.   
      
   Not too difficult... remember than Hubble's optics had a serious defect from   
   the beginning. Also, keep in mind that Hubble optics were limited to 1980s or   
   early 1990s tech (Hubble was launched in 92 or 93, as I recall... it was   
   actually built a bit prior    
   to launch).   
   Hubble was also built for a completely different mission. Hubble optics and   
   sensors were designed for sensitivity, not so much for resolution. The NRO   
   platforms were built for resolution, not sensitivity. So, yes, it is not   
   surprising that the optics    
   alone would be superior to hubble.   
      
   >    
   > Some systems could not be compared, because most of the electronics are    
   > still classified and were stripped out before ownership was transferred,    
   > (now if NASA can just dig up the money to actually outfit and launch    
   > them).   
      
   Undoubtably, this would be the electronics required for interferometric   
   processing algorhythms to sharpen resolution. Resolution itself is limited by   
   the number of pixels available, but interferometry between pixels helps to   
   extract a better image. This    
   is the same kind of processing used in modern combat radar.   
   It is useful to consider that superior resolution tech, in this instance, is   
   not a result of funding, but of legal restrictions. The companies receiving   
   contracts to produce this equipment are restricted by security restrictions   
   that prevent them from    
   selling the tech to other users.   
      
   >    
   > Now, does NASA have better space observation capabilities than the USAF?     
   > Sure, but only because the military doesn't need it yet.   
      
   Honestly, both NASA and the militarygets this tech from the same places.   
   NEITHER develope the tech on their own.   
      
   Something else to keep in mind is the REASON the NRO is providing these   
   platforms to NASA. It is because they do not have the funding available to   
   continue operation of these platforms and upgrade to newer platforms at the   
   same time. Actually, they don't    
   even have the money to simply upgrade these platforms to the newer specs.   
   For that matter, they might not even have te funding to continue operating at   
   the current functional rate.   
      
   That said, you DO have a point that The tech is not available to the military   
   because the military has not yet found a need for it. You must keep in mind   
   that NASA is a government agency that often functions synergetically with the   
   military.   
      
      
   >    
   > If you don't actively cool, they will heat up and become emissions    
   > sources, (well, more of an emissions source).   
      
   Again, this can be controlled to an extent through proper architecture.   
   Let's take a very simple example. Let's say you have 2 solids of equal volume   
   and mass. One is a sphere, and the other is a flat plate.   
   The sphere will present an equal cross section area from all directions. This   
   cross section determines the amount of energy it absorbs or reflects. The   
   energy reflected in any given direction, however, will be determined by the   
   angle and surface area.    
   The amount of energy reflected will be pi*r^2, but this reflected energy will   
   be divided by (at least) 2*pi*r^2. Absorbed energy will be even lower, because   
   this will be absorbed into the entire volume, and that energy, once radiated   
   out (in all    
   directions), will be divided by 4*pi*r^2.   
   The flat plate, OTOH, can be presented with the short edge to the sun,   
   reducing the energy absorbed. If you bevel the sides, this will reduce the   
   reflected energy flux (by area) according to the slope of the bevel. If   
   designed to absorb the maximum    
   energy, this energy will again be absorbed by the entire mass (but remember   
   that you have less energy to absorb). If you happen to be directly above or   
   below the flat side of the plate, you will be receivign almost half of all the   
   energy absorbed.    
   However, as you approach an angle placing you on the same plane as that plate,   
   emission will approach ZERO (depending upon how thick the plate actually is).   
   Defensively, the idea is to orient the plate to face a direction where there   
   is the least likelihood of there being a detector.   
      
      
      
   [continued in next message]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)