XPost: sci.space.policy, sci.astro   
   From: henry@spsystems.net   
      
   In article <1105885111.638247.89710@z14g2000cwz.googlegroups.com>,   
   dexx  wrote:   
   >Is it true that Huygens ceased transmission less than 2 hours after   
   >touchdown?   
      
   Exact numbers aren't on hand, but that's generally right.  Bear in mind   
   that Cassini went below Huygens's horizon around that time, so no further   
   data relaying was possible anyway.   
      
   The primary mission was complete three *minutes* after touchdown.  Huygens   
   was mostly an atmosphere probe; the surface imaging and instruments were   
   an extra.   
      
   >...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.   
      
   It would have greatly increased the cost and complexity, unfortunately,   
   because it would almost certainly have required an RTG.  Moreover, several   
   days is not enough -- it'll be a month or two (I forget exactly) before   
   Cassini goes past Titan again.  You can't really do a long-lived Titan   
   surface mission without better communications support, that is, either a   
   Titan orbiter or a lander that's big enough and heavy enough to carry its   
   own high-power transmitter and steerable high-gain antenna (plus the power   
   source needed to run them).   
   --   
   "Think outside the box -- the box isn't our friend."    |   Henry Spencer   
                                   -- George Herbert       | henry@spsystems.net   
      
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