From: andrew.gray@dunelm.org.uk   
      
   On 2004-06-21, Hephaestus  wrote:   
   >   
   >>     Assuming a dry mass of 3500kg for SpaceShipTwo, it will have a wet mass   
   >> of about 26000 kg.  The X-15 weighed around 23,000 kg, so a Black Knight   
   >> capable of carrying a SpaceShipTwo is certainly not unreasonable to imagine.   
      
   (X-15a was 30kkg, of which 20kkg was propellant, FWIW)   
      
   > But it is the size of a B-52 or larger.  You're either going to have to   
   > modify something off the shelf of similar size, or build one.  B-52s cost   
   > ~$75 million, and that's when you buy in bulk.  That's a lot of money just   
   > for the carrier plane!   
      
   B-52s, being large nuclear-capable bombers, may be slightly   
   overengineered for a carrier plane role in general... ;-)   
      
   One of the reasons the B-52 was used as a carrier plane, I suspect, was   
   that it was there and available, rather than that it was needed; if you   
   can scam a plane off the Air Force for the cost of operations, why   
   design and build a new one?   
      
   The weapons load for a B-52 seems to be about 31,500kg, handily the mass   
   of an X-15, but a laden B-52 could also be hauling some 105,000kg of   
   fuel... and an operational range of Moscow & back is arguably overkill   
   for a carrier plane.   
      
   Anyway, I had a point here somewhere. Hrm. Whilst building a plane to   
   carry something the size of an X-15 is a nontrivial task, and it will   
   end up being large, I don't think the B-52 is an accurate demonstration   
   of the scale of the problem - a dedicated carrier plane would almost   
   certainly be significantly more efficient in the role.   
      
   --   
   -Andrew Gray   
    andrew.gray@dunelm.org.uk   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)