From: snidely.too@gmail.com   
      
   JF Mezei speculated:   
   > Recent events have put a fair amount of debris in potential collision   
   > with ISS and I assume a bunch of LEO satellites.  It isn't the first   
   > time and likely not the last.   
   >   
   > At the technical perspective, what concepts/technolopgies could   
   > pontentially be developped to make a vaccum cleaner for space?   
   >   
   >   
   > Say you can easiuly lauch a ship in same orbit as the debris field and   
   > it can sneak up behind it.  Is the concept of using a laser to vaproize   
   > pieces of metal real or just science fiction?  If you "laser" a piece of   
   > depris, does it just become small pellets of aliminium which then become   
   > bullets that penetrate ISS or other satellites? Or would it render the   
   > aluminium harmless ?   
   >   
   >   
   > It is possible to recreate re-entry conditions that destroy the pieces?   
   >   
   > Or is physically capturing the pieces, put them in a big bucket and   
   > de-orbiting the bucket the only way?   
   >   
   >   
   > Could one launch retrograde in that orbit and spread air in the orbital   
   > path at that altitude such that when the debris hit that air (which   
   > woudld be going at orbital sped in opposite direction) would slow down   
   > the debris and/or burn it up?  (causing both debris and air to drop   
   > down).   
   >   
   >   
   > I am curious to see what science would come up with should there be a   
   > challenge of cleaning space debris equal to landing a man on the moon   
   > and returning him safely before the end of the decade.   
      
   I would consider coming up on a flock of small debris and spraying foam   
   on them.   
      
   From behind, so that delta-v can be minimized at, but then get slightly   
   ahead.  The foam then encapsulates the flock, greatly increasing drag,   
   and perhaps subtracting a tiny bit of delta-v immediately.   
      
   However, I think most debris collection ideas target gathering larger   
   pieces before they become smaller pieces through impacts.   
      
   Laser treatment of small pieces could (in my back-of-envelope world) be   
   done either to vaporize the pieces, which would take a lot of power   
   (B.O.E.), or to do the light-sail thing to them, changing their   
   velocity.  I think either would best be done as an accessory to a large   
   permanent platform (the ISS comes to mind), permanently mounted on the   
   trailing module or truss end.  I'm not sure how detection or aiming   
   would be done, radar might not be effective even at close range, but   
   lidar might help.   
      
   /dps "no, I haven't drilled down in any recent proposals"   
      
      
      
   --   
   Killing a mouse was hardly a Nobel Prize-worthy exercise, and Lawrence   
   went apopleptic when he learned a lousy rodent had peed away all his   
   precious heavy water.   
   _The Disappearing Spoon_, Sam Kean   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)