XPost: sci.space.policy, sci.physics   
   From: fjmccall@gmail.com   
      
   S??gi ?  wrote:   
      
   >On 6/21/2017 8:49 AM, Fred J. McCall wrote:   
   >> "Robert Clark"  wrote:   
   >>   
   >>> "S??gi ?"  wrote in message news:oibn46$tjp$1@gioia.aioe.org...   
   >>> ========================================================================   
   >>> On 6/20/2017 12:31 PM, Robert Clark wrote:   
   >>>> "Robert Clark"  wrote in message news:oi3a88$nck$1@dont-email.me...   
   >>>>   
   >>>> At the distance of the Parker probe, a 1 km sq. mirror could collect a   
   >>>> terawatt of power for beamed propulsion or space solar power beamed to   
   >>>> Earth.   
   >>>   
   >>>>   
   >>>> The Parker probe will use a refrigeration system to lower the temperature   
   >>>> of   
   >>>> the components of the spacecraft from 1,400 C to room temperature. This is   
   >>>> about the same temperature drop as the temperature drop from the Sun’s   
   >>>> surface to the maximum temperature of our high temperature ceramics. So it   
   >>>> should be possible to do this temperature drop on the surface of the Sun   
   >>>> using our highest temperature ceramics.   
   >>>   
   >>> refrigeration wont work. if reflectivity is 99.9% you still ave to move   
   >>> how many terrawatts(?) from front to back of the spacecraft, AND radiate   
   >>> that out to cold space on the backside ??   
   >>>   
   >>   
   >> He wasn't speculating, Bob.  That is what the Parker Probe is going to   
   >> do.   
   >>   
   >>>   
   >>> also Gamma rays are going to cook it, +fry electonics.   
   >>> what are the gamma ray radiation levels close to the sun ?   
   >>>   
   >>   
   >> If you don't know the gamma ray levels, how can you say gamma will   
   >> cook it?   
   >>   
   >> The gamma ray flux outside the surface of the Sun is essentially zero.   
   >> It all gets converted to visible photons from 170,000 years of   
   >> collisions inside the Sun on its way to the surface.   
   >>   
   >   
   >that wiki is out of context.   
   >it seems zero if you compare it to levels within the sun.   
   >   
      
   Zero.  Remember, we're just talking gamma here.   
      
   >   
   >another radiation issue - our south atlantic anomoly cooks electronics   
   >in low orbit sattilites, (earth), an area of trapped radioactive   
   >particals from the  sun.   
   >   
      
   Not gamma.   
      
      
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       live in the real world."   
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