Spricigo

I said it can be used that way, not that is a practical use.

Pretty straightforward. part: drain fuel from the part it is attached to. vessel: drain fuel from any part in the vessel. To surface in a submarine that uses fuel as ballast To use non-trival thrust the valve has. (effectively the lightest engine in the game)

We are? Some people suggest those values for launchpad TWR (I suggest SRBs ) but that is far from ideal values in different situations. For RCS thrusters I doubt there is many player that do something different that the standard procedure (stick some and, as long it don't run into part limits, go with this). As @bewing point out, those thruster are for precise maneuver. You probably don't want velocity adjustment of the order of mm/s2 as he suggested TWR value would imply but yeah, the idea is what he wanted to pass with that hyperbole.

Well, I prefer hoses that anyone can use. Didn't occurred to he an engineer for that, but nice you figured it out.

You can set your antenna to [allow partial] and transmit. Will take longer since you will need to wait for recharging but will be done eventually. Or you may send a supplementary power unit with an outlet to plug the lab in

Is there in the part description, but yea...with so many details is easy to miss something.

Still. You need an actual antenna to transmit science, the one built in in the probe/command module don't count. If I'm not mistaken the actual messages is that a relay cannot be found or the craft lacks an antenna. It is easy to miss since it vanishes so quickly. Also, is quite possible that your relay satellite (with a pair of HG-5 antennas if i get it right) is out of range or out of position, but the lvl2 Ground Station I suppose you also have are more than capable to reach your probe on the Mun. In stock KSP, with very few exception, relays are only useful to solve Line of Sight issues and should be much closer to the weak antennas on the probes and ship out there than the strong dishes on he ground station back in Kerbin no..is among the least heat resistant parts available and is quite tricky to protect too. One way to get around this is to pull the science with a Science Storage Unit and stage away the material bay; another is to set the periapsis much higher in the atmosphere (60-70km) and take several aerobrake passes before finally attempting to reentry.

You are correct, you need an antenna. Depending on the design you may be able to land crash into Kerbin and recover any surviving part for the science or you may send a Kerbal to gather it. But hardly worth the effort.

[snip] Actually, I'm autistic. I know that some of my comments sound snobbish, dismissive and stubborn, but I will never possess the skills to avoid or amend this. That is why I suggest to rather focus in the other part: Thank you.

I know that you are frustrated, but lets get something straight: I have no obligation whatsoever to help you, nor any other person in this whole forum has. Yet, my post contain a link to a serie of tutorial about not only about things you are struggling to do now but also things you will be struggling to do soon. You can take a look and try to learn something or you can ignore and moan about no one helping you. Your choice, not my problem. Now, I can't really assess how good is your grasp of the game mechanics, if you really figured out how to overcome the problem or just managed to do it by sheer luck and persistence. That is why I include things that are essential, but that you can just ignore if you already know it. Also for the benefit for the next guy that will stumble on that thread looking for help with that very same things. In any case, more advanced advice may be offered if and when you provide enough information to convince me those basics are sufficiently covered. It's not worth my effort to try to explain anything more complex to someone that may lack the bases to understand it.

It seems to me that you still need to learn some very basic things before going to the Mun. Thinking that you need to wait a whole year for a launch window to the Mun for example, it screams "I have no idea how orbital mechanics works" . The Mun pass over KSC every 6h, That is how often you get a launch window if you insist in a direct launch but you get transfer windows much more often from a nice low equatorial orbit. You can do a flyby (or even landing) mission with low tech parts and lvl 1 facilities. But without a basic understanding of orbital mechanics and meeuver, you will struggle even with all parts a unlocked and max level facilities.

Since "Buoyancy" is just a result of gravity and pressure and KSP simulate those things i suspect it is. Question is: is the simulation god enough?

What can I say? Seems like not being able to use the part the way you wanted is one such arbitrary limitation. Well, I have a pair of craft and an EVAed Kerbal in my current save that became Kraken's plaything after KIS/KAS interactions. Everything was fine when I switched to pay attention to a maneuver elsewhere and when I came back...instant explosions on not loading. Trying to reload with [unbreakable joints] and [no crash damage] takes ludicrous long and than the craft don't stop spinning while it's parts get shuffled like a bunch of playing cards, and the Kerbal instantly die anyways. So, no. I don't expect things to 'just work' with KIS/KAS. But hey! What cautionary tales are for anyways?! Maybe you can just take whatever you already attached in orbit with Ship Save Splicer, load it in the VAB and hope for the best. Maybe save a bookmark for this post so, if you find any issue I don't need to tell "I warned you".

Unfortunately, you answered your own question. The parts are not designed to do connect in the VAB they way you want to

Don't worry, as long your launch profile is fairly standard and you don't have anything deployed you should be fine. Fairings are available in the Advanced Construction node but or the time being you may try to squeeze the most critical parts inside a Service Bay of keep it behind something more resistant. I'd rather prioritize Propulsion Systems node, which gives you the Osca-B fuel talk, the Ant engine and the Spark engine, those are quite usefull for small satellites/probes. The Miniaturization node provides the first docking port, making offer of station contracts a possibility (those can be fairly easy and lucrative), Fuel System unlocks crossfeed and fuel transfers and Advanced Flight Controls provides RCS systems. As for how to build the "things" there are several good tutorial around that go in more detail, general advice is to design the rocket in inverse order of use(design first what you will use last) with each stage having just enough to do the task at hand plus a small safety margin.

Those elevon 4 are probably too fancy for someone with Aviation by accidental purchase. Fortunately, elevons 1 would be a fair replacement.

Fixed that for you. Because, while I'm also more of a rocket guy, there are quite a few that prefer to play in a "not so rewarding" way

Crashing during 'practice' is fine, we learn with mistakes (sometimes we have the benefit of someone else making the mistakes but more often we need to provide the 'source for experience' ourselves) . However, crashing after a long flight in career is something we'd rather avoid if we have a chance. If you are unsure you can maintain control of your plane during the entire flight (including a safe landing in the end) including a parachute that you use in such emergencies might be a good idea. In fact you may even make this the standard landing method while you don't get enough practice to land reliably without it. Specially when dealing with the limitation of low level facilities and scarce science nodes unlocked, one lack the resources to "brute force" the design to work. If you are ok with mods, there are several that can help (correct CoL, RCS building Aid, Editor Extensions, Precise Editor, ...) but is necessary to understand what option each of those mods bring to the player. Is often the case when asking for help that several people will point the same solution. If that solves the issue at hand, great. However, in the long run, try to consider different options, including some that you will figure out from your own experiments. What work best for me may not be what works best for you and what works best for you in some circumstance may be not quite as effective in a different set of circumstances. E.g. Instead of moving your rear wheels forward you could use canards instead or changed your wheel base to make your lane sit in the runaway in a slight pitched up position. There are pros and cons to each option. (demonstration: the Fly uses the later solution while the main gear was intentionally placed far behind the CoM, )

Nope, the drill only get the bonus from the highest level engineer on board. If there is a mod for that, I'm not aware of.

Well, I accumulate more and more stations/base/etc because I design it to used over and over. So, I thing it's the evidence of dominance thing for me. For the annoying long tracking station list, I use filters and a few mods too.

The big elephant in the room: KSP have plenty of parts to build something that looks like The Shuttle but don't fly like The Shuttle. Different weight distribution, different thrust balance and so on. That is why players come to with "solutions" like severely limit thrust of some engines, adding 'strange' control surfaces, adding ballast and completely change the way it flies. It's not unheard of KSP shuttles that need a Kranken load of reactionwheels and RCS/Vernors to barely follow that desired flight profile. It may look lite The Shuttle but, at least for me, that makes no sense. Flipping the launchpad to avoid a critical maneuver that is likely to throw the craft out of the sky? I'd take it in a heartbeat.

You should be able to get back to Kerbin the same way, when Moho is at the Ascending Node. No idea why you brought up the apoapsis. Also keep in mind, an encounter on the next solar orbit with a little tweaking is less likely to happen because the Kerbin's orbit is longer than Moho's

Mind you, there is more to this than just heat resistance. If you are heavier you slow down less at the same height but you got to lower altitudes in less time where you slow down more. End result is that ou take heat at a high rate but stop in a lower time, before reaching the critical amount. You could get similar result in a lighter craft entering in a steeper angle. Another point is that the heat will flow to the part behind the part doing the aerobraking. The tank behind the engine probably have more heat capacity than whatever you have behind the heatshield.

More generally: why spend money and add mass if the drag is not as significant in comparison? Something to consider is ascent profile. A craft that ascend in typical gravity turn may go with an open node just fine, while a spaceplane need to fly at sea level to cross transonic and expend a lot of time climbing will be in a lot of trouble.

My consideration (Bolded are essencial parts for relays, the rest is there for the sake of a more complete answer): Engines, you need to deploy those satellites somehow. The craft tend to be quite light so priorize engines that are light first and efficient second (ant, spider, one way RCS thruster, 4way RCS thruster, twitch, vernor, puff, spark, dawn, terrier). Solid fuel engines are impractical(not throttlable), thus not considered. Dawn's efficient is so much bigger that it can easily surpass everything else in deltaV, the point is: that so much deltaV is hardly needed, other options offer the deltaV needed cheaper and lighter. Fuel tanks, matching the engines off course.Can carry some extra fuel for eventual contracts asking to move that satellite, otherwise just enough to get the craft where it is supposed to be and adjustments/safety margin. Probecore, The OKTO works fine but may swap it for probes with more SAS option later on for convenience (just be carefull to include a reaction wheel for probe which don't include one). For the Stayputinik the lack of SAS (to esser exents, lack of reaction wheels and top node) is a serious annoyance, though still viable option. Solar panels, consumption is so small that you probably can use the smallest solar panel and get away with it . Placing a few in symmetry and/or using deployable ones helps ensure sun incidence. Gigantors are overkill even on outer planets but by the time you can reach those places you can afford it. Antennas, should be relay antennas and should take in account distance and what we have in the other side of the connection. (e.g. HG-5 are fine for bouncing the signal around a planet/moon but not for an interplanetary link, even in the first case the other craft need to have at least more than it's internal antenna.) Is not worth to combine weaker antennas if a stronger one is available. Batteries, what your probecore have is probably enough. Even if run dry (e.g. using reaction a lot in the shadow of a planet) solar panel will eventually recharge it and allow the needed corrections but batteries are conveniently cheap and light. fuel cells, complement or/and alternative to solar panels and batteries but I'm yet to see a case for relay deployment that it is better than just more panels/batteries rapioisotope Thermoletric generator, great for that application, a bit pricey. The real issue is that it lies in the end of the tech tree, by the time you unlock it is likely to already have more relays than you care about. Science instruments, those can be dropped after used (contract that requires it completed, science transmitted) and either terminate the dropped stage in the tracking station, let it crash in a celestial body or recover it with a different craft. for use elsewhere. That is more of a conveninence if expecting/planning to do reposition contracts. Positioning, unless a contract asks for a specific orbit just pick it yourself. High elliptial polar orbits work better for long range satellites which main job is to ensure link with KSC while circular equatorial orbit work better for short range relay which main job is to ensure link with the other craft there. Coverage, there is two ways to improve it 1)carefully positioning to maximise conection time of each satellite 2)having more satellite able to connect to/from.