Source : Webster's Revised Unabridged Dictionary (1913)

Ascensional \As*cen"sion*al\, a.
   Relating to ascension; connected with ascent; ascensive;
   tending upward; as, the ascensional power of a balloon.

   {Ascensional difference} (Astron.), the difference between
      oblique and right ascension; -- used chiefly as expressing
      the difference between the time of the rising or setting
      of a body and six o'clock, or six hours from its meridian
      passage.

Source : WordNet®

ascensional
     adj : tending to rise