Stuck on last 3:
24a An old instrument for measuring distances to a heavenly pole
?E???H ?E?T??
22d Computing measure of processing speed
???AFLOP (either MEGA, GIGA, TERA, PITA depending on 24a)
10d "A journalist of the baser sort or sponging prophet"
?L?E?E?-S???E?E? (seems to be FLEET-STREETER with 2 extra spaces)
Any help appreciated