This attribute clears all B-Plane points from any previous run - in all graphics windows - before the current run.
Astrogator <Satellite Object Path> SetValue ClearBPlanesBeforeRun <Boolean>
Set this attribute to true to clear all B-Plane points before each run of the MCS; otherwise, set it to false.
Astrogator */Satellite/Satellite1 SetValue ClearBPlanesBeforeRun true
STK Programming Interface 11.0.1