A group of people are trying to recreate the Soviet Vega missions in Celestia: launch, Venus lander separation, balloon deployment, and Comet Halley encounter. Unfortunately, it's proven difficult to find trajectory data for the mission. SPICE kernels exist for a time span of about two weeks around the Halley encounter, but that's it. Any pointers to trajectory information for other parts of the missions would be much appreciated. Other information that would be interesting is the approximate course of the balloons in the Venusian atmosphere. I'm not expecting that we'll be able to replicate the trajectories of all components to the millimeter, but we'd like to avoid using 'artistic license' as much as possible.