I believe you are just "seeing" Field Rotation of an ALT/AZ Mount. The Satellite is traveling in a direction that is not in the same Equatorial Axis of the object (NGC 2903). The cam is exposing for a few seconds, then transferring that image to the image stack and aligning the image based of the chosen Field of View Stars.
When the stacking / aligning process is occurring the cam is not taking an image. This process can take a couple of seconds, but the field continues to rotate (maybe 5 arc sec per second). When the next image is taken the field has rotated with the object, but not the satellite. Thus the satellite will show a continuous zig zag motion, but a straight line durning the actual exposure.
You resolution is 1.7 arc sec per pixel which is quite good and the object in the image looks very good. Pat Utah