Do you repurpose upper stages (and how)?

[Supernovy]

Struts from stack separators could fly off on their own like that.

On topic, I just so happened to chuck some panels, antennae and a probe core on my manned orbital launcher's "Automated Orbital Stage":

I figured that if the upper stage is going to remain in orbit, it might as well be of use. I had some delta-v to spare, too.

[Dunbaratu]

Struts from stack separators could fly off on their own like that.

Hmm. Well that's annoying. Because attaching struts from the adjacent parts to the separators is often necessary to stiffen them and stop the rocket from banana-wobbling on liftoff. If I have to stop doing that because my save file gets all cluttered with 'strut' debris instead of 'real' debris, then it becomes a lot harder to design rockets. (Because I *want* the problem of dealing with my debris, I don't want to be spawning 8 new bits of tiny strut debris with each launch as that will "circulate out" all the older debris since I have to limit the debris amount or it clogs the CPU time.)

[CoriW]

So recently I've actually not had an "upper stage", my current series of lifters consists of a central rocket and 4 liquid fuel boosters.

I have 3 lifters in my "Titan" series, the "Titan UltraLight" which can lift 18 tons to LKO, the "Titan Light" which can lift 27 tons to LKO, and the "Titan Heavy" which can lift 58 tons to LKO. The way they work is during the trip to orbit they drop their boosters on the way up, then after dropping off the payload the central rocket has enough fuel left over to perform a landing back at KSC. Although the central rocket doesn't have enough DeltaV to get back into orbit or anything like that, I've now been inspired by those rockets to try and design a reusable launch vehicle with a modular payload system that can be re-loaded using docking ports and probably a makeshift crane using KAS.

I mean I know we don't currently have a budget or anything, but if we did then a reusable launch vehicle would be invaluable!