Question for my astronomer-on-speeddial @uastronomer (or AstroFedi!)

I asked over on Threads, and received a couple of plausible sounding speculations, but nothing definitive. Wonder if you can shed more light on this.

When I view the projected trajectory on NASA’s official Artemis tracker page (nasa.gov/missions/artemis-ii/a…), if you align it to match the plane of the Moon's orbit, you will notice that most of the outbound coast (including the original orbit of the Earth) happens mostly in the same plane as the Moon's orbit, i.e. only moving in the X and Y axis, but no real movement in the Z-axis. But the fly-by results in a dip “downwards” (from the reference of my recording) in the path, i.e. Orion doesn’t stay in the exact same plane as the Moon's orbit after flying by the Moon, but rather starts moving along the Z-axis as well, by quite a bit. What is the reason for that Z-axis movement in the trajectory post fly-by?

#Artemis #ArtemisII #NASA #artemis2 #Orion