tavert

Mk2's or either of the adapter parts work too (same mass ratio). The Mk1 is subpar, but at least it's a convenient shape.

Abusing the rules with both jets and an impractical amount of Xenon: http://imgur.com/a/tyX0H#0 29066 m/s in orbit, just Gemini (did you mean Mercury??). Not enough patience to do anything with ion engines. I think the TWR is too low to even land the ship on Gilly, maybe after using like half the xenon...

Although due to the way KSP's drag model works right now, if your rocket uses aerospikes then it will be more stable if the aerospikes are ahead of the COM.

Any feelings on jet upper stages? Ion? And what is the minimum usage of a single BACC that counts for the first stage? Does it need to get off the pad from the very initial lighting of the BACC (so max pad mass = 315/9.81 = 32.11 t), or does it still count if some of the solid fuel has to burn off before TWR reaches 1 (max pad mass = 6.375 + 315/9.81 = 38.485 t)?

I was watching a video of a speech Elon Musk gave at Oxford in November (http://www.oxfordmartin.ox.ac.uk/videos/view/211), where someone in the audience asked if he had ever played KSP. Evidently some of his employees do, but I guess he hadn't. If whoever asked that question is on here, thanks! Though my advisor and girlfriend may have some disapproving words for you... Edit: whoops it wasn't the Oxford speech, it was the Royal Aeronautical Society speech from around the same time, - I'll leave the other link there since it's an interesting talk too

Upon recreating the craft from the tutorial with Kerbal Engineer / MechJeb handy, it looks like those first 2 stages only have ~3000 delta-V total, assuming you use the boosters before the core and don't have any fuel lines. So looks like you're doing fine, but maybe the tutorial could use some rewording. It was also difficult for MechJeb to control that rocket (didn't try it manually) without using all the RCS fuel for the ascent, so perhaps fins or LV-T45's instead of LV-T30's would be a good idea.

I built this ridiculous thing to get an orange tank into orbit on 6 jets and as little else as possible, mostly as a test of what MechJeb2 is capable of. http://imgur.com/a/Hdew6#0

Ah right, since you're returning to the same orbit via aerobraking that makes sense. MechJeb's aerobraking prediction has been spoiling me. I hadn't heard of it either until someone posted a challenge to recreate it before the forums asploded. So relay-thanks to them, whoever it was... I think Google cache is mad at me for doing too many KSP forum cache searches.

Looks pretty similar plan to the TROY reusable earth departure stage concept: Any reason for 200km parking orbit? You'll get more Oberth effect if it's lower, and it would be easier to bring all the components to. The only possible downside is if it's too low, the initial part of the burn (assuming you aim for roughly 50/50 before and after the node) might dip you slightly into the very top of the atmosphere, causing a tiny bit of drag on your way back out.

A) The wiki might be rounding to the nearest "nice" number KSP might use hardcoded values for some physical constants that don't match reality. Pretty sure this is the case for standard acceleration due to gravity, maybe true for others.

The changes between .18 and .19 were pretty minor, all the components in that rocket should work exactly the same. It says "first two stages to get into orbit and the third to circularize." I don't have KSP open right this second but it helps to use Kerbal Engineer (or MechJeb, or similar) to quantify a delta-V budget per stage, from there you can determine roughly when in the flight each staging event should happen. (all numbers below in m/s) ~4500 dV to circular orbit, depending significantly on flight path ~860 to transfer to the Mun ~250-300 to circularize in Munar orbit (depends on your exact transfer trajectory and altitude you circularize at) ~600-900 to land (depends on your TWR and how aggressive your suicide burn is) For a return mission, you also have ~600-700 to get back into Munar orbit ~280 ejection from Mun orbit back to Kerbin aerobraking altitude