brdavis

It's not even remotely possibly realistic… so asking for "the right value" doesn't make sense. It's like asking "what color is middle C?" Generally, the Roche limit is about 2.5 times the radius of the primary body… if you want to be more precise, there's a factor of ratio of the densities of the two objects in there as well. And then there's the deformation into a triable ellipsoid that both Laythe and Kerbin would suffer given their rotation rates, not to mention the tidal distortion as you approach the Roche limit. And you could use the classical "touching spheres" limit or the "homogeneous fluid body" approximation… which do you prefer? And all of this assumes one object is much much smaller than the other… which isn't the case here. If you want wild fun Roche limit problems… grab a copy of Forward's "Rocheworld", and read up (and yes, it includes trying to take an airplane of sorts on a trip between two worlds that just about share their Roche lobe… and the plane has to start as a raft falling down a waterfall between the worlds, before gaining enough speed to have enough lift to fly). But here… there's no realism to be had at that level. A lot of fun "wow I wonder what happens to a model when I break nearly all the assumptions it's built on" sort of questions… but realism, here, isn't any of them.

The physics are horribly broken? Huh... As a PhD that teaches university-level physics and has built 100-level labs around KSP... I'd have to say I'd disagree. You may see the aero model as a fatal flaw... but many of us seem to enjoy playing the game just fine in stock, and if we want something beyond stock... add in any number of advanced mods. Improved aero isn't even in my personal "top ten" list for KSP... and a lot of what was previously on the list (working radio with occlusion and range, resources in some form, better scanning, complex fairings) has been added in. If "playing with cow poo" isn't a viable option for you... don't play with cow poo. Many of the rest of us seem to be just fine with it

Huh. I thought that was just me. Had an un-modded career game suddenly go south when I finally got a nice science station into Munar orbit. The next time I came back to the game, the station was there just as i'd left it… with no Kerbals on board at all. All three had simply… vanished. Not dead. Not back home. Not on the station. Just mysteriously missing. I called the save "The Rapture" and restarted (new version was coming out that was going to break my save anyway).

What module manager are you using? I just tried replacing the one that I had with a fresh install of ModuleManager 2.6.13 , and no-go: science is still sitting there in the lab, even though power is consumed and transmission percentages increase until 100% is reached… no science transferred. Which version did you find that works (for you), and where did it come from?

Yep, just lower your pericentron down deep into the atmosphere, re-entry will certain occur, no problem what so ever. Drag does that :)

Read it. Learn it. Love it. And play KSP on 'Nightmare Mode': https://what-if.xkcd.com/68/

Nearly had to do a 2nd Accident Report Board… this time I sent my first rover (unmanned but with a seat) to the Mun in career, with the follow-on scientist in a lander. Scientist, not pilot, but no biggie because there's a probe core on the lander. Which works fine with power. And yes, I remembered solar cells. The Munar intercept trajectory was an impact, but that just takes a tiny correction at the end (& I was aiming at a specific set of surface targets). No problem. I had not, however, noticed that the next maneuver would occur during that blasted Kerbin eclipse. She managed a burn in the blind (without being able to rotate the stupid ship, darn SAS-without-power) just enough to avoid making a new green-tinted crater, and then when the ship came out of eclipse limped into orbit. We'll see if she can land herself and the rover anywhere near each other now given the propellent reserves. Admittedly this wasn't as bad as an early tourist-to-orbit contract. ProTip: tourists are in trouble if the ship is without power to deploy 'chutes via probe core. That was a really sad day...

No worries, I just missed it. It has that balance for you (and, to be honest, many others). For some of us, it's not been a problem in stock, and we deal with it OK. My balance may be different than your balance… which is why the conversation is good to have. A similar thing seemed to happen when people first ran into the new Stock Aero model, and all their rockets started flipping out… especially when they turned to 45 degrees at 10 km or so. Flipping out made things harder… and I loved it. Because, honestly, that's how the real world works, and I get a bit of a thrill trying to solve simplified versions of real world problems. Like a shifting CoM relative to the CoD, or POGO and bending moment resonance. I've had rockets on SAS ascent that start wobbling… and I have to take manual control to reduce it before tripping SAS back on. To me… that's a game feature, not a bug. I'd honestly miss it if it just "went away". I get that, and understand. But the reason they devs "left it that way" may very well be for the reasons I mentioned above (their preference point may be different from yours), or even because they aren't done but have more important tasks at the moment. My priority list seems to be different than yours in this regard… are we so sure that the devs priority list isn't likely different (perhaps for very good reasons) than yours or mine? They may be quite realistic for the stock game. RO is not the stock game… and it may indeed require KJR. But Squad isn't developing RO.

Hmm, that's a good point - just what percentage of users do you think have a significant problem with fairings? Evidence? Personally I've not had a problem with them… yet. I like them actually. But I admit I've not played with interstage fairings much yet, and I tend to design rockets the way they work IRL. For those… you don't end up using complex fairings. You use preconfigured stock ones that are even more restrictive than KSP's. I'd say more flexible fairings aren't needed quite as much as deployable mechanisms (yeah, I've not tried Infernal Robotics yet… but might have to soon).

Actually each SRB attached to the ET at two points, fore and aft, and those were not simple single-point connections either… and the upper one connected to a very heavy beam through the inter tank section of the ET, a beam that flexed during thrust. and the SRB's themselves flexed during use (remember the "puffs of black smoke" from the Challenger SRBs?). One of the Apollo Saturn V's had POGO vibrations strong enough to break the interstage fairing around the LEM and have it fall out of the launch vehicle. Real rockets flex. A lot. In dangerous and difficult ways. I think assuming that the developers have "left this in to mimic real life" might be stretching it, but it would probably be a mistake to say that it's "not fair" or "not realistic". Why not just turn off aerodynamic heating? Or properly modeled something else? There's a balance. Where that balance has been chosen… is not a simple process. - - - Updated - - - Too bad - it's actually a well-written and very informative post, with a lot of good details… about KSP, and the real world. Thank you PB666 Well, I guess to offer another IMHO… I don't have a problem with it. Yes, there's some wobble… but less (far less) than I've dealt with in the past. And it's something that I can deal with using strategies that mimic (and teach) real-world rocketry. Resonance is something that happens in KSP… and in the real world. Detuning a stack is something that, just like delta-v, Isp, or proper staging, I can have fun with, and learn from, KSP.

…or separates stages, or fairings, of boosters...

You mean the same way you have to have Kerbals actually spend game time in the science lab to accomplish a task, a game dynamic that was explicitly added by Squad… while people keep commenting on the purported fact that "time is free in KSP"? Yeah, i find that cognitive dissonance odd as well.

Nice one this morning. First career manned Munar landing, good. Making it back to a 28 km Kerbin perigee with only 12 units of fuel remaining, great. Forgetting to put a decoupler between the Mk1 capsule heat shield and the propulsion module with the landing legs etc… more than slightly exciting, as things started exploding during reentry.

On the original question… I'm mostly a stock type person. There are several mods I've used, and will use again (KAS is fun to build with, KA is incredibly useful, DRE and TAC add a lot, and I like the challenge of RemoteTech, PreciseNode incredibly useful, etc.)… but at the heart of it, Stock (for me) is about the challenge of staying within the limits laid down by the designer. There's a game within a game - the developer lays down a challenge and the rules, and the player sees if they can rise to that challenge. A first-person shooter with an infinite ammo code isn't the challenge the designers released to the wild, although it might be fun. Getting to Jool is pretty easy via hyperedit. So at least at first, I like accepting the challenge as described. That's all. Nothing special or magical. Yep, they made it movable so (wonderfully!) if I don't like that challenge, or want a new challenge, I've got plenty ready and waiting. Disclaimer: that's just me. I may be weird. But… it's a wonderfully wild, weird, diverse community. And having said that, one other point… My passion, and training, is physics; I teach planetary science (among other things). And while I don't do it professionally, spacecraft theory & design is something of a passion of mine. So for me, doing all those calculations like delta-v, launch window timing, gravity assists, etc. is FUN. Being able to "do it myself" is actually one of the reasons I play. With a simple calculator, a pencil, and lined paper by my side. Yeah, that's incredibly strange to some folks I know… but being able to actually DO the science and engineering is why I went into the fields of study I did in the first place. Handing all that fun back over to MechJeb and KE would… reduce the game for me. Like I said, we're a very diverse, and weird, community

Agreed. LH is annoying stuff to work with - low density, cryogenic, etc. If you want a 'realistic' fuel for a KSP NERVA… then those tanks aren't oversized. Probably undersized.