So I've been playing with kOS and wondered, just how far could I take this if the vessels didn't unload? Then I figured it can't be that hard to stop unloading.
And so here we are - TT NeverUnload.
Allowing you with suitable mods to fly two vessels at massive distances appart!
contrary to its name it doesn't NEVER unload, but it is definable in the CFG what distance unload will occur, and the default is massive (300km). Its fairly unlikely you'll need more but you can get more with a simple tweak if you ever need it.
To use, just place it on whatever you don't want to disappear and right click in flight, then press Enable. on vessels with multiple neverunload modules, activate BOTH before seperation, else parts may unload anyway.
You want pictures? Here have some of the included vessel (with kOS code, but obviously not kOS itself, included!)
Detaching at 15km, the payload continues ascent alone.
Giving you just enough fuel to reach the pad for spaceX manpatrick landing.
EDIT: forgot I should probably make this clear:
The payload DOES continue on and not unload of course! (if you followed the start procedure right that is) so heres looking back down on the KSC at the launch rocket. The payload flies almost all the way up by itself but the kOS computer does for some reason fail when coasting to apoapsis, perhaps a range issue for them. There is plenty of time to switch to and circularize however after landing.
This is a first release of a game stretching mod, so it is pretty buggy but usable. For now don't use it on your main save, but its good fun.
License for the mod is available in the readme.txt file included in the download.