From: someguy@somewhere.se.retro.com   
      
   Matthew Montchalin wrote:   
   > Bill the Cat wrote:   
   > |>>|Once ISS' electronics are fried by the Van Allen belts, it will be   
   > |>>|a dead hulk...   
   > |>>   
   > |>>Can you describe the extent of the 'frying?' Is there going to be   
   > |>>so much electrical charge that it arcs around the ship and melts   
   > |>>holes through it?   
   > |>   
   > |> No, nothing so spectacular.   
   >   
   > Then I expect the ship to remain airtight if there aren't going to   
   > be holes burned into it.   
   >   
   > |> The semiconductors in the electronics will simply start glitching,   
   > |> become erratic, and finally stop working altogether due to   
   > |> accumulated radiation damage.   
   > |   
   > |The interesting distinctions come when you consider the other equipment   
   > |*controlled* by the electronics; e.g. when the solar array drive   
   > |electronics die, the solar arrays can no longer be pointed at the sun   
   > |and so everything will be starved of power.   
   >   
   > However, if the ISS is first given a nice spin - something that is   
   > generally incompatible with telescopes that are usually expected to   
   > maintain their focus on things - there ought to be a 'continuous'   
   > source of power from the solar panels.  The starvation for power   
   > won't be from any lack of incidental solar radiation.  There might   
   > be some malfunctioning from the radiation of the Van Allen Belts,   
   > but it will probably be from a series of voltage spikes, wouldn't   
   > it?  A resistor goes here, a resistor goes there, and after a while   
   > a trace on a circuit board melts, shutting down that part of the   
   > component.   
   >   
   What you are talking about is not radiation damage, it is discharge   
   damages due to spacecraft charging. As almost any modern spacecraft is   
   fairly well designed to avoid charging effects in space, discharge   
   damages are nowadays very rare. Radiation damages are not dramatic   
   (unless you are talking about Latchups, Single Event Gate Ruptures and   
   such transient phenomena) just a more or less slow degradation of the   
   component until it finally malfunctions.   
      
   --   
   th   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)