Tracking objects in space requires very specific tracking-rates, depending on the object your interested in tracking.  lunar, solar, and the Sidereal rate for stars.  For satellites, things get interesting fast, and each one is different, and requires (for the most part) knowing its orbital elements for a specific point in time.  The call this data, a Two Line Element Set or TLE.

For satellites, things move pretty quick and I need to have some idea of what tracking or slew rates this mount will be capable of, or all of this is for nothing.

The stepper motors I'm using are 1440 steps/rev, and have a 30:1 gear reduction.  So this makes things interesting if I would like to have a 5° / second tracking rate:

I have my doubts that these motors will handle 1250 RPM!