Neptune system space probe "Verrier-Galle". Roughly based on a "Neptune System Explorer" study from 2011 by JPL and NASA, which would be a Cassini-style spacecraft exploring Neptune and its moons.
I had started working on this back in 2015, then abandoned it for another 2 years, then picked it up again in late 2017, to finally rediscover and finish it this week. Thanks @kowalska_kaska for cool Neptune facts that reminded me about this piece 🛰️🚀