[amsat-bb] Re: New Cubesat - the Ultimate Fox Hunt

[G0MRF@aol.com]

In a message dated 09/08/2009 19:42:06 GMT Standard Time, nss at mwt.net  
writes:

Why is  it that all re-entries always end in the ball of fire over just a 
few  minutes.  Why cannot the re-enetry energy be disipated over a longer  
period to make it more survivable.  Of course, if they could, they  would.  It 
appears to be the nature of the beast. You are entering an  ever denser 
medium, so the drag has to escallate and you end up with the 6/7  minute burn.
>
>What if the surface of the re-entry vehicle  radically changed during the 
re-entry phase?  As the density of the  atomosphere increased, the surface 
area decreases.  An ablative system  that instead of burning off a thin skin 
of material as in most re-entry  systems, you planned on burning off 95% of 
the original drag volume?   What re-entry profile could be achieved  Could 
we make a golfball core  "pinger" that could survive?



Or, the not so 'cube'sat structure is an aerodynamic shape made from a cast 
 ceramic material which glides in at a shallow angle allowing the energy to 
be  dissipated over a much longer period of time.
OK the solar cells burn off but an internal antenna would be OK as ceramics 
 are fairly transparent to RF and a battery would provide the final hour or 
so of  tlm. 
Would love to see the temp readings as it comes down.
Would not love to be on the final end of the trajectory when it  arrives.
 
David   G0MRF