Today I went to Eve in a ship designed to go to Duna... Yeah, it turned out as good as it sounds...
A little backstory: Right now I'm playing in science mode, and after a botched Mun landing I needed some serious science points to progress. I've already been to Minmus (in a Mun lander, but halfway in the burn I realised that I don't have enough dV, so I went to Minmus with a Mun assist {more about that mission later}), but I've never really left the Kerbin-Mun-Minmus system...
So I designed the Duna Express Vehicle (D.E.V.), a permanent in-space craft (kinda like the Hermes from The Martian), with more than enough dV to move around Duna and Ike. After putting it into orbit with minimal fuel and a refueling mission I noticed that I'm in the middle of an Eve transfer window. Quickly sent out the D.E.V. to Eve and soon after I sent a lander probe to gather more science from the surface. It wasn't until the D.E.V. left Kerbin SOI that I realised I forgot to bring the barometer and the thermometer (yeah...) The probe had them, but it couldn't communicate with Kerbin directly. So, I made a course-correction with the probe so it arrived at Eve 12 days before the D.E.V. and instead of directly descending to the surface it stayed on a highly elliptic orbit over Eve. I made the high- and near-space tests and waited for the D.E.V. When it arrived I got back the com. link with Kerbin, so I sent back the data and prepared for the actual descent. Meanwhile I realised an another design flaw in the D.E.V.: it doesn't have enough dV... (again...) Similar to the descent probe I could get a stable elliptic orbit but not enough fuel to leave. Since I was stuck I did the science, relayed everything back to Kerbin and received some data from the surface via the probe.
At the end of the day I got the science I needed, but I have 4 kerbals in a highly elliptic Eve orbit in a fairly heavy craft with about 300 units of fuel left. I'll have to plan a rescue mission...
Moral of the mission: Next time I'll need more fuel...