bewing

You realize that you've got a couple years to wait for an efficient launch window back to Kerbin?

On an escape trajectory anywhere near Kerbin, your rocket will still have an upward velocity on the order of 3000 m/s. So stopping would require an additional 3000+ m/s of dV. That kind of dV takes quite a bit of mass, and launching such an upper stage to an escape trajectory would be very expensive early in the game. As Deddly said, a probe core is the correct answer. It makes your rocket into a robot. The probe core probably needs an antenna and some solar panels, so that it has a long life -- and can send back science reports from beyond Kerbin, for science points.

The DLC gives you many new parts. They are not very powerful, but most of them have variants to play with.

Ditch the advanced reaction wheels. The SAS system is using them to put a lot of torque on your rocket, and that makes your rocket bend. Additionally, the smaller the joints between sections are, the more bendy they are. You have a .625m-sized joint near the top of your rocket. That is probably the worst bendy point. You can always use rigid attachment to reduce bendiness. Also, autostruts can help to reduce bendiness too. And if you use them, you can get rid of the normal struts.

The only sort function I see is "relevance" vs. "date". So where are you seeing more options than that?

Craft files are just text files. So you can right click, choose "open with" and choose notepad, wordpad, or any other text editor. Make sure the extension is set back to .craft once you are done editing it.

Engines can be occluded, but RCS thrusters can't. They are always supposed to work, even if they are buried deep inside something else.

So that mod creators could add them to mods.

Nope. Never seen anything like that before. I rarely use RCS myself. Would need a craft file to test.

I don't believe so in sandbox mode -- but in career mode you can use a few cheats to create a setup that's exactly the same as sandbox mode, with the structures downgraded as you said.

That's a somewhat different bug with the wheels & landing gear suspensions. It tends to happen on low-G worlds -- but it's not a problem with minmus specifically. There is a cheat you can use on kerbin called "hack gravity" to lower kerbin's gravity to match minmus. Actually it lowers gravity in the whole universe, so if you want to use it for testing landers, it's best to test in a separate sandbox game, so nothing important gets messed up. But yeah, try hacking gravity on kerbin, and then tweaking the "spring" and "damper" values on your landing gear. You can often fix/minimize that kind of silly jumping problem by doing that.

In KSP, there is a known issue where wheels do not act precisely round. They have "dents" in them that are 45 degrees forward and behind vertical. It's being looked into by the devs, but there are no promises as to when it may be fixed. You will have to apply some force to get the rover to come back down to resting flat on the wheels. One additional problem with that is the command keys, and whether you have any reaction wheels on your rover. If you have no reaction wheels, then simply pushing W should accelerate your rover, and that may be enough to reorient your rover. Or maybe hitting S to accelerate backwards, and then suddenly braking. If you do have a reaction wheel, and you leave the controls set to the default -- then pushing W causes your rover to accelerate forward and also causes it to pitch down ... which is not what you want, because it tends to keep things they way they are. It may also be why your rover ended up sitting the way it is now. The easiest way to fix that is to go into the settings and pick some other key for "forward" and "back", for your rover. I like Home and End, myself. If you design your rover so that there is a fair distance between the wheels, and the CoM is close to the middle -- then just the weight at the CoM will overcome the "dents" in the wheels, and the rover will fall down by itself.

I actually think it's a good idea to do a lot of those contracts. After you do a bunch, it gives you a really good feel for which SRB boosters can get how much payload how high and how fast. Tweaking the thrust percentages on the boosters will fine tune your launch if you were going a little too fast the first time. And landing your rocket again will give you a good idea of how much mass a parachute or three can handle. But as said above, if you want to get it done quickly then you need to use a liquid fuel engine that can be throttled. By steering and playing games with the throttle, you can usually complete a contract in a few tries. The important thing is to be flying almost horizontally in the target altitude range, so that you have a long time to match the proper speed. Also note that the speed requirement is always a surface speed -- which means you may need to change your navball mode.

Welcome to the forums. The orbit displayed in green must be matched to a fair degree of precision. That is, your blue orbit needs to be right on top of the green orbit. Your current orbit seems to be significantly rotated with respect to the green target orbit. If you right click on the An or Dn values on that green orbit, it will display how close you are to matching the proper angle for that orbit. You want that number (the An or Dn) to go to zero (well, technically 3 degrees is probably good enough). Please pay attention to the fact that the target orbit also has a required orbital direction. You have to be going the right way around the orbit to make the contract complete. Once again -- getting the An and Dn values to go to zero will guarantee that you are going the right way 'round. In general, your attempt to match the Ap and Pe numbers is excellent, and is actually much better than is actually required. But it's actually much more useful to match the plane of the target orbit first, and then match the Ap and Pe after that.

It's a relic of previous ages, as steve_v said. It serves no purpose currently. It just never got removed from the UI.