From: henry@spsystems.net   
      
   In article <5dcb47db.0404271220.2edbd6ec@posting.google.com>,   
   Mike Miller  wrote:   
   >So...How do you land megatons of metal annually without resorting to   
   >beanstalks, tethers, or anti-gravity? Just aerobrake big ingots and   
   >let them drop into the ocean or an artificial receiver lake?   
      
   In principle, you can just form it into suitable reentry shapes -- hollow   
   spheres might be good, you want something light enough that it decelerates   
   aerodynamically to near-zero terminal velocity -- and hard-land them in   
   some convenient location.  It's probably better to just lease a big chunk   
   of desert rather than fooling around with water; you don't much care   
   whether they break on impact.   
      
   In practice, you may have a problem with nitrogen-oxide formation during   
   reentry, and possible adverse effects thereof on the ozone layer.  This   
   is not a big deal for modest numbers of manned spacecraft, but aerodynamic   
   braking of megaton quantities of materials would be a real concern.  Time   
   to warm up the rotating tethers.   
   --   
   MOST launched 30 June; science observations running     |   Henry Spencer   
   since Oct; first surprises seen; papers pending.        | henry@spsystems.net   
      
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