This Addon demonstrates a bug in Celestia v1.6.2b2 and in Celestia v1.7, showing that ScriptedOrbit definitions are ignored.
The CEL:// URL below takes you to a viewpoint which should show a purple sphere (named "Scripted") dancing around a smaller yellow sphere (named "Test Object"). It works when using Celestia v1.6.1. Celestia v1.6.2b2 and Celestia v1.7 both draw the purple sphere at a fixed location, centered at the location of the yellow sphere, thus hiding it. No error messages are generated by any of the versions of Celestia.
The example ScriptedOrbit was taken from the Celestia Wikibook, expanded slightly to provide visible objects. See https://en.wikibooks.org/wiki/Celestia/Trajectories#ScriptedOrbit