XPost: sci.space.policy, sci.astro   
   From: millerto@bellsouth.net   
      
   dexx wrote:   
   > Is it true that Huygens ceased transmission less than 2 hours after   
   > touchdown? Whilst it was a magnificent achievement to travel so far and   
   > land perfectly, it seems a great shame that the probe was so short   
   > lived.  I'm suprised the designers didnt make it rugged enough and   
   > powered enough to survive several days.   
      
   one design limitation factor was the length of time that Cassini would   
   be "over the horizon" wrt the lander. Huygens doesn't have powerful   
   enough transmitters to relay the datastream directly to Earth, so having   
   longer batt life wouldn't do anything but waste money and resources if   
   it couldn't see its mothership and thus transmit data.   
      
   Building enough transmitter power to send to Earth directly would very   
   likely have major scalability issues, which in turn would have a direct   
   impact on other mission profiles (maybe they could have had a powerful   
   transmitter but little or no instrumentation to feed it data, f'rinstance).   
      
   Mission planning for any tpye of space vehicle is a series of tradeoffs   
   between various things: time, money, propellant, payload, *type* of   
   payload, mission duration, mission capability, etc. etc.   
      
   Bottom line: for any launcher and any vehicle and any mission profile,   
   there's only so much you can include. Add more of thing X and you have   
   to take away from things Y, Z and A'.   
      
   --   
   Terrell Miller   
   millerto@bellsouth.net   
      
   "Every gardener knows nature's random cruelty"   
   -Paul Simon RE: George Harrison   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)