On Wednesday, June 27, 2018 at 10:37:11 AM UTC-5, David Ellis wrote:   
   > So, as the title suggests, I am trying to consider potential options for the   
   reaction control thrusters of a space warship.     
   >    
   > The general design is a vessel in the tens of thousands of metric tonnes   
   range (wet mass, that is) with fusion-powered nuclear thermal drive system and   
   using slush hydrogen as a reaction mass--obviously what is stored as hydrogen   
   slush is exhausted as    
   hydrogen plasma.     
   >    
   > In any case, I am trying to weigh my options for the reaction control   
   thrusters on this warship, hoping to employ thrusters that would not require   
   me to employ additional types of reaction mass.  That leaves me, however, with   
   a rather small selection    
   of engine types to consider.  I'm leaning toward arcjets, since it seems as   
   though they might be my best choice for a non-nuclear thermal rocket using   
   monopropellant.     
   >    
   > Any ideas from the rest of you folks?   
      
   Hydrogen tanks leak 1% of their hydrogen a day. You are better off storing   
   your deuterium fusion fuel as heavy water (D2O). Separate the Deuterium prior   
   to entering your fusion reaction chamber and dump the excess oxygen into the   
   exhaust stream as an    
   afterburner to increase thrust.    
      
   As a side bonus, heavy water has a density of 1,107 kg per cubic meter instead   
   of deutrium's 169 kg per cubic meter. This means that your ship can be built   
   to naval ship density instead of being a giant balloon, which makes it easier   
   to radiation shield    
   and armor.    
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)