LoadingToLightness:

--------------------------------------------------------------------------
   Sail lightness parameter from loading (mass/area). 
   The lightness is the dimensionless ratio of solar radiation pressure force
   to the solar gravitational force.

   Since version 7.
--------------------------------------------------------------------------
   Form:
   beta = LoadingToLightness( sigma )
--------------------------------------------------------------------------

   ------
   Inputs
   ------
   sigma         (1,:)    Sail loading (kg/m2)

   -------
   Outputs
   -------
   beta          (1,:)   Sail lightness parameter 

--------------------------------------------------------------------------
    Reference: Colin R. McInnes, "Solar Sailing: Technology, Dynamics and Mission
               Applications", Springer Praxis, London, 1999
--------------------------------------------------------------------------

Children:

Common: Graphics/Plot2D