El Sancho

https://ksp.sarbian.com/jenkins/job/MechJeb2-Dev/

Sounds ironically quite like the problems with the 737-Max8 which led to that aircraft type being grounded. Boeing stretched the fuselage to increase the range, and added new engines which were heavier and more powerful. This led to relocating the wing to a less-than-ideal position, which could lead to nose-up problems and eventual stall. Boeing then installed a special autopilot module to push the nose down under certain conditions, with the intention that this should counter the nose-up problems, but they had this module keyed to a single sensor, with no redundancy. And they told the airlines that pilots would need no new training. So the single sensor malfunctioned, the special autopilot module pushed the nose down and down, and the pilots had no idea what was going on, because they had never been trained about this or even told that the module existed. Aside from the two incidents which led to crashes, there were other incidents which did not lead to crashes because the pilots simply turned off the autopilot. Ahem, back on topic, I would then ask what is different about the SABRE engines? I have never used them, but what makes them unique?

Wow, that's impressive! In a way this makes me think of something I'm wrestling with right now - how to hook up various pieces on the Minmus surface in order to form a surface base too big to land in one piece. Related to this is also the issue of how to handle refueling. HOW can I land a rocket and somehow hook it up to a surface base that is mining and refining fuel. Minmus gravity is low enough that I can probably just jackass it together by using some RCS thrusters for lift. Who knows, if the component has enough lift, the Docking Autopilot might even work. Then again, I suppose such discussions don't really belong in this forum; they are questions of how to use MJ, rather than reports of bugs in MJ. Hmm, is there a forum for discussion of the use of MechJeb?

I teach English online, and much of my working day consists of waiting for students. So, given that my major was Political Science and some of this stuff goes waaaaayyyy over my head, I decided to look up this Jezewski's algorithm just on the basic principle of self-education. When I Googled it, I found to my amusement that the first results are related to "uterine contractions and fetal heartrate". Apparently this is the work of Janusz Jezewski, whereas the rocket-related stuff is the work of D.J. Jezewski. The rocket stuff does show up further down the page, but my initial reaction was along the lines of, "Ahhhh, Whiskey Tango Foxtrot, Jim?"

I also confirm the business of MJ showing double the Delta-V reported by KSP itself. On the subject of launch to plane, I was having all sorts of weirdness and inconsistent behaviour. Then I tried Jim's suggestion above. I nuked my existing MJ2 directory in C:\Program Files (x86)\Steam\steamapps\common\Kerbal Space Program\GameData and did a fresh reinstall from the archive of ver 875 and now it seems to work fine. My tentative conclusion is that my habit of updating MJ by simply dragging the MJ2 directory from the new archive to GameData and choosing "overwrite all files" is not sufficient. Some vestige of an old version was apparently remaining and ****ing things up.

I am very glad I could help. As Robert Heinlein said long ago, "if you can get your ship into orbit, you are halfway to anywhere". Of course, that is only true in an allegorical sense, but it's still a useful thought. If I might offer another suggestion, Minmus is easier to land on than Mun. Minmus has a shallower gravity well, and also has the Flats, which offer large level areas in which to land.

As shown by red arrow above, you can select three different styles of gravity turn. Since you are new, I suggest you use the one shown, the CLASSIC Ascent Profile If you still have problems, tick the box below that, and a window will pop up where you can move a slider to the right to increase altitude at which gravity turn begins. Note that Orbit Altitude of 75km shown in this pic is not recommended; you should set it to 100km if it doesn't default to that. Note also some other options selected in picture are also non-standard. Auto-stage should be selected, for most purposes, but is not in picture. Limit Q should usually be left at default of 20,000 rather than lowered to 18,500 as shown in picture. Force Roll may or may not be desirable. In my case it keeps rocket steady; you should use only if rocket is rolling without it. Also, since you are new, I will mention that Sarbian and Jim DiGriz are both coders of this mod. Advice or information received from them should be heeded above all others.

That's what I was thinking, Tonka Crash, but I wasn't really sure enough to speak up on my own. I often use that "Control From Here" function after an undock just on general principles, to be sure MJ and I are on the same sheet of music

Glad I could help, in my somewhat bumbling manner. I knew what was happening, but you figured out why! Tip of the hat to you.

I have encountered that on Minmus and Mun. When it happened to me, I checked the Ascent settings carefully, and found that the altitude at which it was set to begin the gravity turn was too high. Everything else was right, but that one parameter had no been autoset correctly, i.e. down to something like 1km. When I adjusted that manually, it all worked. This has happened to me at least half a dozen times over the last few months, and every time the problem was the same.

Umm, it's not a problem, bro. I was jumping it quite deliberately to show how well the stability assist functions. My rovers are working great But thank you.

GOOD to know it's not just me The weird thing I notice about Fine-Tune is that if I leave it at the default 200km, I wind up with a periapsis between 125 and 150km, but if I boost it up to about 350-400, it will come very close to that figure, so it doesn't seem to be a consistent offset.

So, in practical terms, if I'm launching from Kerbin to Minmus, it's still best to launch with "Orbit inc." at zero degrees and just resign myself to expending the ~230 dV to match planes? That's what I've always done, because I've never been able to get the fancier functions to work.

Of course, I could be entirely mistaken but I think the meaning of the reply is that it's already taken care of, and you should not be getting any message about incompatible with 1.6.1 Personally, I am using MJ Dev 858 and KSP 1.6.1.2401 (WindowsPlayer x64) en-us and I'm not getting any compatibility messages. You can always get the latest dev version at - https://ksp.sarbian.com/jenkins/job/MechJeb2-Dev/

Ah, so desu. In that case, you should probably ignore my response and just go with what Jim said. After all, he and Sarbian code this stuff. I'm just some guy who plays the game

Forgive me, please, but I'm struggling to understand your description of the problem. 1. In the Landing Guidance window, are you using "Land at target" function or the "Land somewhere" function? 2. In the Landing Guidance window, do you have the "Use RCS for small adjustment" function selected or deselected? 3. When you say "boostback direction" do you mean prograde or retrograde? (if you're not sure about these terms, use SmartASS module to experiment and see which is which) All the above said, are you allowing for the fact that when you activate the Landing Guidance module, it often continues to circle the Planet/Moon for a while to get into position? When this is happening, there should be three additional lines of text at the bottom of the Landing Guidance window, below the "Use RCS for small adjustment" option. They will read something like... Status: Moving to high deorbit burn point Step: Deorbit burn Mode SafeDescentSpeed Policy (false) If you are seeing those, there's nothing wrong. If you have the Autowarp option activated, this step can take a while. If you don't have Autowarp selected, it can last bloody forever...

I'm always glad to be of assistance

Do you have Module Manager installed? I was asking about this same issue a page back, and learned you need MM for that functionality to be activated.

Following answer is all TTBOMK, (to the best of my knowledge) This is usually a hopeless cause because as soon as the ejected parts get to be a certain distance from your ascending rocket, (the figure 2.2KM sticks in my mind, but wouldn't swear to it), the system deletes them to prevent the engine from bogging down in too many calculations. They just disappear, POOF! Better to strip all that expensive stuff from the ejected parts and just consider them a write-off. Basically all you can recover is the part that lands. And this isn't a MechJeb thing, it's a KSP thing, so there's nothing Sarbian or Jim can do about it. Again, the above is all TTBOMK, based entirely upon my own experience and memories of previous conversations on the subject

Ah, so desu! In that case, I'll just keep using the MJ box, given the posts above about MM causing weirdness in the VAB. There is always a certain advantage in using MJ only, in that it completely eliminates the possibility of weirdness caused by incompatibility of mods. Thanks for the reply, Tonka. I noticed that 846 adds some new buttons at the top of the Ascent Guidance window.

Forgive me, please, if this is a stupid question, but... I just upgraded my MJ version from 830 to 846, and I'm not getting the MJ functionality without the actual MJ module. Not that this is any real problem, but I thought that was now a default feature. For the record I am not using any mods other than MJ. No Module Manager, no nothing. Is it perhaps that MM is required in order to get that "MechJeb For All" type function?

Hahahaha, oh god, the joys of software development. One group of users clamors for a given feature, you do the hard work to make it happen for them, and another group of users asks you to disable it. I'm not blaming anybody, or meaning to be disparaging anyone or their ideas, I'm just thinking what a thankless ****ing task it is developing software at all, let alone for free. SMH

I'm confused; is it now necessary to use MM in order for MJ to work?

Ahh, so desu. In this case it's more like "and" than "or" ? Well, it's 2:30am right now; I'm busy punishing my liver with a bottle of cheap red wine, baking bread, and watching "Dumplin", so I do believe I'll check that in the morning. Jebediah's first axiom - Never EVER drink and KSP. Cooking, now, I can drink and do that like a pro, thanks to 50 years of experience. Plus, let's face it, making bread isn't exactly rocket science. You only really need 4 ingredients, and there's people can't spell their own name that make bread every day of the world like it was nothing. ****** EDIT ****** OK, it's the next afternoon, I'm sober again, (for now), and I'm happy to report that upgrading the Tracking Station did indeed unlock Maneuver Planner as it should. Thanks very much, Jim, for pointing out the solution to that non-problem, and apologies for wasting your time. And a grateful shout-out to Sarbian for all his hard work.