practical dV ceiling for rockets?

[Streetwind]

Alright, I'll be marking this thread as "answered" for now since there's a large amount of maths and pretty graphs available here. That's not to say we need to stop discussing though!

[Padishar]

Sure, here's the craft file for the lander. I stripped the lifter portion out because it is so large that it makes scrolling around the VAB a real chore I did a quick check on the parts used, and you'll definitely need AIES, NovaPunch, KW Rocketry, RLA Stockalike and SCANsat to load this craft. And KER of course. The data circuit is taped to the narrow decoupler between the lander and the satellite, which by the way is also the core part of the whole assembly.

I had the default Realism Overhaul already set up so all I needed was SCANsat. I've installed that and taken a look and it looks like the problem is caused by the staging simulation in KER throwing the whole rocket away because the decoupler is the root part. This is a bug and I'll look at fixing it asap...

[Streetwind]

Addendum: I tinkered some more today and was able to increase my dV slightly by shifting around the setup of the individual stages so that they are more uniform. In other words, instead of having 7,200 in S1 and then 1650 in S0, I made S1 smaller and S0 bigger, and also similar things with the other stages. Unfortunately a hard TWR limit prevents me from doing this perfectly across the entire rocket, but it's great to see that I actually learned something valuable here. Future rocket designs will definitely be built with a more uniform stage setup in mind.

I also stripped down the lander to its bare necessities for surface science, moving the satellite and four of the six one-use experiments (meant for high and low orbit) to a secondary rocket. Which means that I am now up to 25,400 m/s dV on the lander mission. Shelved the orbital refueling idea for now as the big lower-stage engines I have are not restartable, and no engine that is is powerful enough to lift this rocket. But with over 25km/s, my gut feeling is less worried. That should leave me around 10km/s to brake out of the interplanetary transfer more or less directly into a landing. Now gonna sleep another night over the newly gained information and see what else I can come up with.