Try this little experiment:
Get a buddy and practice catching each other with webs/scrams.
Get one person just to orbit at 15km in a faster ship then have the other pilot align to a planet and hit full speed.
What happens to the orbiting ship?
Has it started to spiral in a cone behind your ship?
What happens when you reverse direction and fly through the cone?
Now stop the centre ship. Watch the orbiting ship settle into a perfect orbit at 15+/- km, base it's orbit on a clock face, as the ship comes to 9o/ck, burn towards 12o/ck, what happens?
Try again, as the ship hits 9o/ck burn towards 12o/ck, as soon as you see the other ships vector change stop and immediately fly to 6o/ck, the ship should pull a 180 turn and fly straight at you, immediately hit approach and overheat prop and tackle.
Try it with different times within the orbit, what happens if you burn straight up or straight down, does that make a difference?
Is there away to break someone's orbit, does the server respond the same predictable way each time? Can you force someone closer? can you force someone further out?