FinalFan

According to @bewing, the problem lies in autostruts. 1. Landing legs are automatically autostrutted to the heaviest part. 2. This feature cannot be disabled by any means. 3. Upon docking, landing legs that find themselves on a ship with a new heaviest part will suddenly revise their attachments accordingly, involving "large forces" that can be "extremely violent" for large and vulnerable objects. I would not expect whether the legs are retracted to matter.

It turns out that landing legs don't like it when you dock and the heaviest part is on the OTHER ship. Thanks to @bewing I was able to continue the mission without cheating or re-launching.

Thanks for telling me the theory behind what was going on. I love to learn that kind of stuff, and it might even come in handy someday.

I filled one of the large tanks in my Eve ship's center stack, and that seems to have done the trick! Thank you very, very much. Fortunately, the refueler was completely devoid of struts.

Yes, I have enough fuel that a S3-14400 in the Eve ship's center stack will outweigh a S3-7200. I take it you believe that may help.

Thanks for the input. I have not intentionally been using autostruts; is it off by default? (I have a fair number of struts on the Eve ship but are these distinct from autostruts?) There are 16 landing legs, and they do seem to be on the parts that want to die. As for the most massive part ... there are a lot of big ones on the Eve ship, but since the fuel tanks are mostly empty the heaviest single part is probably a full S3-7200 fuel tank on the refueling ship (I didn't have the S3-14400 tech when it launched).

So I've been going through career stock and I happened to notice that I was in the middle of an Eve transfer window. This inspired me to get really ambitious and try to do an Eve land and return mission. I designed the whole monstrosity myself—it's probably way oversized because I tend to do that, but according to the math it should be able to put my kerbals back into Eve orbit where they will rendezvous with another group. Obviously a setup rated for Eve is capable of SSTO, which I did, but I didn't really plan very well so I needed to send a refuel mission. I just so happened to have a couple of very large tankers lying around which seemed perfect. I sent them to the Eve ship and very, very carefully set up a docking maneuver that was close to the normal-antinormal ideal. I came in, decelerated to 0.1 m/s, and ... the Eve ship spontaneously exploded. What? [edit: TinyPic is dead; long live Flickr. Original link for insanity posterity: http://i64.tinypic.com/ibi0i0.jpg ] Even Jebediah was shocked. I wasn't really sure what would provoke such a violent reaction. I mean, sure, the part count was getting a little high, but the docking maneuver was almost as gentle as humanly possible, and I'd already spent many minutes in physics range. Maybe the reaction wheels are the problem? I turned SAS off and docked on pure RCS ... the final connection was noticeably more wobbly, and it took longer after the connection was made for the explosions to begin, but ultimately the result was no different. This seems very stupid. Is there anything I'm doing wrong other than "don't build such big stuff"? Is there anything left worth trying—for example, could it make a difference to completely shut off the reaction wheels instead of just shutting off SAS? If I decide to cheat, is there an easy way to tell the game to fill up the fuel tanks? Additional information: the explosion is not catastrophic in that the vessel as a whole survives. The vessel begins to tear itself apart but settles down after certain sections are torn free. The sections in question were intended to be the stuff I detach when preparing to depart Eve. Mining equipment, some science stuff, AND the majority of my reaction wheels. But turning the authority down to 0/100 and setting them all to Pilot Only doesn't seem to make a difference. Is it possible that it would help to switch to the Eve ship as the main vessel (i.e. point-of-view ship) when the docking is about to succeed? The refueling ship is the one with RCS but I think it's not possible to avoid the explosions with the way things are now.

So I've been going through career stock and I happened to notice that I was in the middle of an Eve transfer window. This inspired me to get really ambitious and try to do an Eve land and return mission. I designed the whole monstrosity myself—it's probably way oversized because I tend to do that, but according to the math it should be able to put my kerbals back into Eve orbit where they will rendezvous with another group. Obviously a setup rated for Eve is capable of SSTO, which I did, but I didn't really plan very well so I needed to send a refuel mission. I just so happened to have a couple of very large tankers lying around which seemed perfect. I sent them to the Eve ship and very, very carefully set up a docking maneuver that was close to the normal-antinormal ideal. I came in, decelerated to 0.1 m/s, and ... the Eve ship spontaneously exploded. What? [edit: TinyPic is dead; long live Flickr. Original link for insanity posterity: http://i64.tinypic.com/ibi0i0.jpg ] Even Jebediah was shocked. I wasn't really sure what would provoke such a violent reaction. I mean, sure, the part count was getting a little high, but the docking maneuver was almost as gentle as humanly possible, and I'd already spent many minutes in physics range. Maybe the reaction wheels are the problem? I turned SAS off and docked on pure RCS ... the final connection was noticeably more wobbly, and it took longer after the connection was made for the explosions to begin, but ultimately the result was no different. I'm very frustrated right now.

I also had a strange problem after lifting off from the Mun: while building up velocity attempting a direct insertion to Kerbin reentry, I suddenly heard an explosion from the map screen. Oh no! Was I too low and impacted the surface at nearly orbital speed? No, I still seemed to have altitude, but my main fuel tank somehow exploded and the rest of the ship was in six pieces slowly drifting apart. (Engine, forward section, four side attachments.)

The one thing I never feel bad about "cheating" on is that if something goes awry because I didn't know the distance to the ground instead of the distance to "sea level", I shamelessly revert.

Yep, very spur of the moment. I was going to head to LKO with a partly full ore load, when I decided while on my way to the maneuver node that instead I would just stop and drop, fill up, and do a direct burn to LKO. Gonna have to be careful of that mountain when I take off, though.

Today I decided to land a very large mining vessel on the Mun in darkness, for reasons. It turns out my intended landing site was the side of a mountain (70° or more), so I slid down the slope for a long time, but I had enough fuel to fool around some. Eventually I got to the foothills, which were still about a 20° slope, but the lander is pretty wide and bottom heavy so I figured it would be able to stay put when I turned the RCS off. I was mostly right, except for the "stay put" part. I slid down the slope at 0.4 m/s for a couple of minutes. I was worried I would just keep going (since the motion stops me from going to the tracking station) but eventually I stopped. Whew! I considered taking a picture, but ... "on the Mun in darkness" pretty much covers it.

Come to think of it, maybe I am still being stupid, but why do mass ratio and TWR even matter? You need Isp to know how much fuel you burn per Delta V, and you need to know how much mass you're starting with, and then ... ? For example, it's intuitive to want to know the thrust, but does it actually matter? More thrust makes a shorter maneuver but would the breakpoint percentage change? I can't think of a reason it would. Likewise mass ratio only matters when you run out of fuel. I am actually half convinced at least one thing above is wrong.

I am stupid right now, can those two things give you Isp?

I think I've seen this sort of thing once or twice before but didn't know what they were called. Now I'm torn between wanting to use actual nomographs and wanting to use the word as a nickname for picture menus. Either way, thank you!

Oh man, I was addicted to that. I kept doing survey rockets until they started giving me ones far enough away that I could no longer do suborbital hops to them with my Thumper + Terrier setup.

Thread was inspired by the following story. I am a new-ish player on my first career mode. I haven't gotten serious about setting up relay satellites in Kerbin system. I have a bunch of rescue/salvage contracts around Minmus that I am scooping up with a pod of Klaw-equipped probes, but I cheaped out on the probe modules and they don't have "aim at/away from target" or "aim at maneuver node" (OKTO II). I also apparently forgot to equip them with antennas, so they are out of range of direct Kerbin control. I thought I had a relay satellite in position to help with controlling these probes for at least part of their orbit, but apparently I was wrong. So I'm stuck moving in the six cardinal directions in 100% throttle blasts with no maneuver nodes. Getting an intercept and a rendezvous was relatively easy, but this is a salvage mission so I needed to actually snag the thing with the Klaw. So I need to not only make physical contact, but I also have to make the Klaw actually point towards the object while the probe intercepts it ... without actually being able to tell the probe to point at the object. After several over-corrections (by slipping a keystroke and burning longer than intended) and a lot of tweaking, I finally get myself to a point where I'm drifting slowly into a position about 12 meters radially out from the object. Point radial in, give it one last short blast, and ... contact! Perfect catch! I felt like a god.

Your first miner had 16,000 battery power? Wow, it must have been a heck of a prototype! My first mining vessel was just a Mun lander with refueling capability, but even my first "real" mining craft only had about 6,000 units. I figure, either it's got a solid power source and it doesn't need that much, or it doesn't and it's going to run out regardless. I guess more batteries would help you refine in orbit on the dark side as well as the sun-side without running dry... and I did slap at least 20K of battery on my first asteroid miner because I didn't want to use fuel cells.

Oh, yeah, I see what you mean. Yeah, IRL build time can definitely add up too. Right now I'm doing "simulated" test launches of this awful monstrosity of a mining ship. In games I'm often "lazy" in a way that actually means more effort so I'm pushing my design competence to its limits trying to launch it with a full load of ore so it can push another thing to the same destination body and land, while not needing to be refueled after helping itself to Kerbin orbit, and also while also not using more than one Mammoth to get it to orbit (currently trying Mainsail asparagus). I think I'm on the verge of making orbit but I also thought that five tests ago. Update: success! Instead of six Mainsails I used two pairs of Twin Boars (so, eight boars total ) and tucked gimbal-locked Vectors in between them on the sides of the core recoverable booster. (And, of course, 4 sets of 4 Kickbacks collectively carrying 63 seconds worth of fuel.) It made orbit with the greatest of ease, and with a little tweaking can even put the recoverable booster in orbit for high-value recovery.

Yeah, I'm a fully satisfied customer, lol. I can't even imagine how much it would change my game to have build time. It's like completely antithetical to how I have been doing things.

I haven't had anything as utterly logically pointless as ARS, but I've gotten a contract to activate a Thumper on a suborbital trajectory ... at 210,000m ... and I've gotten it twice now on my first career. On the other end of the spectrum, I got a contract for Mun science just as my third Mun mission entered its SOI.

But "space-daring" is also accurate

I see. Thanks again.

So refueling at Gilly, and then going to Eve, would have left you with too little fuel to slow down to "non-explodey" speeds?

This post was originally created as a response in another thread: Thanks for all the details, and the link! I checked it out. One reason I asked my question is because I was intrigued by your vessel and decided to try test-building and launching an equivalent. It was based on eyeballing your picture and description so naturally it did not have the NERV transfer stage that you had already jettisoned. It made orbit fine. I have a lot less experience than you, and I'm still working on my first interplanetary experience (though I've done some "proactive asteroid intercepts"), but it seemed on paper that the core vessel itself ought to have enough to make it from Kerbin system either directly to Eve or refueling at Gilly (to use on deceleration as in your post). (The massive fuel tanks compensate for the lower efficiency vs. NERVs.) Is this just a design choice you didn't want to do, or is there a reason this wouldn't work for your plane such as that yours is heavier than mine, or am I just completely missing something? How many drills does your plane have? I only put 2 large drills in mine. On second thought, this might be going off topic, so I think I will put a copy of this post in your Project Intrepid thread.