XPost: sci.physics, sci.space.policy   
   From: fjmccall@gmail.com   
      
   JF Mezei  wrote:   
      
   >On 2017-05-25 21:11, Fred J. McCall wrote:   
   >>   
   >> Yes and no.  Again, Range Safety is primarily concerned with where the   
   >> thing could conceivably come down and that's all physics.   
   >>   
   >   
   >In the case of an SRB, can you really predict where it would/could go if   
   >it prematurely separated and flew like a wild firecracker?   
   >   
      
   They can't instantaneously change their velocity vector (physics and   
   shit), so you'll see it changing toward the danger zone.  When it gets   
   close to violating range constraints you'd blow the TTS.   
      
   >   
   >Wouldn't there be preventative detonation instead of waitiong for teh   
   >firecracker to become clear and present danger to land?  (kill it after   
   >malfiunction instead of waiting for it to start flying towards coast).   
   >   
      
   You could certainly do that, but you'd potentially blow up some 'good'   
   rockets that way.   
      
   >   
   >Different slant:   
   >   
   >Say the rocket worked flawlessly but a radio failure blocks telemetry   
   >from reaching SpaceX.  Does Range Safety have pre-calculated expected   
   >position for every second of flight and as long as the rocket is   
   >nominal, it lets it go, or would the loss of telemetry reception result   
   >in decision to detonate ?   
   >   
      
   Depends on the rocket.  In general a loss of TM will lead to blowing   
   the vehicle because if you lose comms from the rocket to the ground   
   you have to be concerned about losing comms from the ground to the   
   rocket.  Manned vehicles get more leeway.   
      
   We used to put vehicles on the NAWC-WD China Lake range whose   
   capability exceeded the size of the range.  We would fly them across   
   one range, through a tiny bridge between ranges onto a second range   
   and then across that range.  I know we blew at least one 'good'   
   vehicle because it took a slightly wide turn going into that 'bridge'.   
   It was on its way to recovering to predicted track, but they blew the   
   FTS anyway because it was outside the corridor predicted by the   
   vehicle simulation.   
      
      
   --   
   "Insisting on perfect safety is for people who don't have the balls to   
       live in the real world."   
                         -- Mary Shafer, NASA Dryden   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)