[X] My Assistant

[ncc1701d]

What do NASA scientists use for the "origin of longitude" when calculating orbits for Spacecraft that orbit Venus?
I assume they use the Venus Equator for the "reference plane" but what else do they use to get the "Longitude of asscending node" ?

According to Wikopedia for a geocentric orbit around earth they use earths equator as the reference plane and the "First Point of Aries" as the "origin of longitude"

My interest is in orbits around Venus though and finding the the "Longitude of asscending node" so I need to know what they use for "origin of longitude".
thanks.