I've recently mastered interplanetary navigation enough to able to do a manned Duna return. Having done that, I set my eye on a loftier goal, a manned Laythe return. Now, I like to meticulously plan everything in advance, but in this case, don't have all the info. And what better way to fix that than by starting a generic-named Howto thread, and dump a bunch of vaguely-related questions into it? First question concerns those delta-v maps I see floating around. As I read them, I need a vessel in LKO to have circa 4000 m/s delta-v for the return trip, assuming aerobraking on Jool capture with the resultant apoapsis around Laythe's orbit. But, I am unsure (How much to kick that periapsis out of Jool atmosphere? How costly is the Laythe capture?). What are the rough requirements, assuming liberal use of aerobraking? Secondly, my Duna mission vessel had abysmal TWR, which resulted in rather long burns. Not long enough to jeopardize the mission, but long enough to annoy me. How low do people commonly go, before low TWR becomes a serious problem? And lastly, it looks to me that the best way to go about designing a Laythe lander is to build a hybrid jet and rocket powered VTOL SSTO. Which raises a whole host of questions, since I can test my designs on Kerbin, not Laythe, and I don't want to overbuild the lander to make it Kerbin-ascent capable. My current design has around 1500 m/s delta-v as reported by MechJeb and Kerbal Engineer, which I think accounts only for the rocket-powered ascent phase. Is there a good way to find out the delta-v of the jet phase? I guess I could build a purely rocket-powered ship with 2800 m/s delta-v, and try and match its ascent profile with my hybrid lander, but that wouldn't be entirely accurate, since I imagine jets perform slightly differently on Laythe. Or do they? Anyway, thanks in advance for any insights, I'm sure as I keep designing I'll stumble into more questions.