Another commission piece for longibando.deviantart.com/
This one has an orthographic view of the Lorentz, an interplanetary research vessel built in collaboration between ESA and the Russian space administration intended for a journey to Titan, the largest of the Saturnian moons. The service module in the design is much smaller than the main vessel, which is also the lander that will touch down on Titan. The Lorentz is powered by a nuclear main engine which is internal, and the service module is powered by a very large Radio-Thermal-Generator(RTG). Service module has 2 parts: a) tanks module, b) weapons satellite, which remains in Titan's orbit once the ship departs. RTG wouldn't be operational until then.
The Lorentz carries less than ten crew, in cryogenic hibernation inside the main stage, and the ship thus has only minimal living space despite the large size. The ship consists mainly of fuel tanks, engines, fuel lines, stuctural parts, etc. For surface operations it also has a small rover on board.
The Lorentz features in a novel about it's journey to Titan as well, 'Sombras en Titán', by José Antonio Suárez. It's in spanish, so if you know the language, you can read about this ship.