From: henry@spsystems.net   
      
   In article ,   
   Marc 182   wrote:   
   >> The hurdle you run into right up front is that fairly trivially you can,   
   >> using technology known since the 1950s, get all the supplies you need   
   >> into about a kilo a day per person...   
   >   
   >What's life like living on a kilo a day? Baby food out of a tube?   
      
   Baby food and/or tube food is almost all water, the last thing you want   
   for efficient packaging.   
      
   You'd eat freeze-dried or dehydrated food -- quite like what you'd eat on   
   a backpacking trip, perhaps packaged a bit differently -- rehydrated with   
   recycled water.  Uninspired, but reasonably varied and pleasant, menus.   
   Occasionally, as a break from routine, a bit of frozen whole food or a   
   vegetable or two grown on board.  (It *is* worth growing a few plants,   
   partly as a diversion and partly to add some variety, although they   
   wouldn't be a major component of the diet.)   
      
   Yes, recycled water.  Nobody, but nobody, gets by on a kilogram a day   
   without water recycling.  You need more than that just in drinking water,   
   and when you figure in showering, dishwashing, and laundry, you've got to   
   recycle almost all of it.   
      
   You can recover enough *potable* water for drinking and food preparation   
   from air dehumidification, using water vapor from washing as well as from   
   people.  You need enough non-potable water -- sterile and safe but perhaps   
   not looking pure or tasting good -- to require recycling all three kinds   
   of wash water, and recovering most of the water from urine.   
      
   You can accept some small water losses, because human metabolism converts   
   food to CO2 and water, so any system which isn't doing food recycling   
   shows a water excess.  So you don't need to recover water from solid   
   wastes, and you don't need full recovery from urine.   
   --   
   "Think outside the box -- the box isn't our friend."    |   Henry Spencer   
                                   -- George Herbert       | henry@spsystems.net   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)