Ascensional (&unr_;), a. Relating to ascension; connected with ascent; ascensive; tending upward; as, the ascensional power of a balloon.
[1913 Webster]

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.
[1913 Webster]