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Posts posted by FinalFan

  1. My lander took off from Minmus and put itself into a prep orbit to return to Kerbin; it was a low orbit but I checked the trajectory in map view and it looked like it had comfortable clearance.  But as I followed the ship, its altitude above the surface dwindled to 87 meters before increasing again.  Well, whatever, I made it ... but then I had another close encounter a mere 26 meters above the surface!  Map view shows a gap between trajectory and surface that should plainly be bigger than that. 

    Conversely, in the past I've seen the path sink into the "ground" on map view while I was still a hundred meters up.  I had thought it was just because I was suborbital and "close enough" to the ground, but now I'm wondering if it was the same phenomenon in reverse.  Is this a known issue? 

  2. I've been advised that this is the place to post SSTOs. 

    Big Plane to Anywhere
    (Nice try, Bill, but I don't think this is what they meant by "long range ISRU craft"...)

    BPA 4R

    I've been fooling with this for quite a while, and recently I decided to inflict it on the world.  It may not have as much chrome or avant garde cred as some people like, but I think it's stylish in its own way.  It carries 6 kerbals and has all the standard science and a science lab to examine it in.  It makes LKO with 2800+ dV still in the tank (as of 1.8), and holds 4600+ after refueling with two large drills (4700+ if it's practical to launch on just the NERVs). 

    BPA minmus

    The design isn't very minimalist; if anything, it's focused on having lots of bells and whistles:  for example, it has two front wheels because one is better for taxiing (can steer) and the other is better for wilderness takeoffs and landings. 

    It's been fantastic so far for doing all kinds of missions in Kerbin SOI (I got a surprising number of requests for 5-kerbal capacity thingamabobs); it's also en route to Jool but said Kerbin missions are slowing down the clock.  I'm pretty happy with it, but welcome any constructive criticism. 

  3. I'm just spitballing here, but I want to share a thought about why it might be that there is so much trouble over "only" 350m/s.  

    First, let's consider airbreathing mode.  This is the "easy" part, not in terms of designing it or flying it but in the sense that the very efficient jets give you a huge head start on the dV you need for orbit.  Let's say the jets do all the work of going up to 1200ms, and 2/3 the work of 1200-1500m/s, for 1400 out of 2400.  (More than 2300 because orbital speed is higher at lower altitude.  For simplicity I will ignore the altitude and atmosphere and hope it isn't too far off.)

    So you're going east at 1500 (surface) and need to be going 2400 (orbital) and you get 175 for free (surface speed assists orbital speed).  That leaves only 725 dV that the rockets need to supply, plus 100 they already did for 825 total; and the rockets are always less efficient than jets and also less powerful on a NERV spaceplane like yours is.  

    Now you want to go west instead, and the difference in dV of orbiting the other way is only 350 (2400+175 instead of 2400-175), but it's not 350 added to 2225, it's 350 added to 825, or a more than 40% increase in the work the rockets have to do!  No wonder you had trouble, when putting it that way.  

  4. After reaching higher tech tiers, I use the Flea almost as often as I use the Reliant.  (The Swivel, on the other hand, still occupies a genuine if narrow niche for my vehicles when I want a cheap second stage and the Cheetah isn't strong enough.)

    You know, what would really make the Flea more attractive is a built-in decoupler.  I dimly recall that a big reason I stopped using it was that the decoupler cost twice as much as the booster.  It probably just seemed like a stupid waste of credits.  And there's precedent now with those Making History capsules.  On the other hand, that's just an extra complication for people trying to learn the basics of the game, so it's probably best not to have it as standard equipment, but possibly an upgrade as in your idea. 

  5. 1 hour ago, AHHans said:

    Well, you always want the CoM in front of the Center of Pressure (CoP), if it is not then you'll have to actively fight against the tendency of your craft to flip. (Which can be done with enough control authority.)

    @bewing already said most of it. One additional issue is that you should keep in mind that the CoP moves when you go through different flight conditions: at low speeds in dense air it is dominated by lift, so close to the CoL. At high (hypersonic) speeds in thin air it is dominated by drag, so it will be close to the center of drag.

    If you have a craft with lots of high-mass but low(-ish) drag components at the tail - like rocket engines, the nuclear engines in particular - then the center of drag for the fuselage will be quite a bit forward of CoM of the fuselage. So if you design such a craft to be just stable at liftoff, then it will probably become quite unstable during your ascent to orbit. If it keeps controllable will then depend on how much control authority you have and on your ascent profile.

    Thanks for the advice.  With SAS off, it has a slight to very slight nose-up effect above 300 m/s.  Basically, I'm satisfied with its controllability in normal flight.  But I was wondering if I was contradicting any community-identified "best practice" with my placement of the CoM.  There could be a situation I haven't considered where it's horrible, you know?  [edit:  Or relying on fuel placement to be stable during aggressive reentry could be considered a crime against kerbalkind.]  If it's just known and identified tradeoffs like "better for low and slow (e.g. landing and takeoff), but you have to be a lot more careful on ascent path" then that's fine. 

    What kind of rules of thumb can I use to guess at my center of drag?  For instance, the CoM is about 60% of the way towards the back from the front; is that relevant? 

  6. TL;DR:  is this generally considered a "don't do this" type of thing for spaceplanes, or just a tradeoff?


    Hi, I've been refining a Mk3 "do-everything" spaceplane for a while now (all science, ISRU, amphibious, etc.) and I'm wondering if I'm making a mistake with the balance.  The default CoM is very stable and just a tiny tiny bit forward of the CoL, but I understand that although these being very close makes the plane more maneuverable, it also makes it more vulnerable to loss of control.  My question is:  is this generally considered a "don't do this" type of thing for spaceplanes, or just a tradeoff? 

    —Liftoff/landing:  CoM and CoL being on top of each other is good here, right? 
    —Ascent:  CoM being somewhat ahead of CoL makes the plane more stable.  But if it seems pretty controllable then is there a reason to worry? 
    —Reentry:  CoM being somewhat ahead of CoL makes the plane recover from aggressive reentry profiles.  Is it reasonable to say "I expect to have some fuel left to create this condition for reentry" or is that considered a bad design?  (It needs 10% fuel to ensure recovery from radial out position)

    Basically, I like the idea of maximum agility (for a Mk3 spaceplane) but I don't want to overlook a fatal flaw. 

  7. Like many of you, I've experienced serious issues with landing legs having excessive bouncing.  But it's important to remember the promise of landing legs.  I landed a probe on Minmus lately on a slope and this happened: 

    Landing legs

    I came down vertically and the legs automatically evened me out.  It was beautiful.  Hopefully this is what we can have right from the beginning in KSP2, and new players can experience this without bitter memories of landing leg shenanigans. 

  8. 11 hours ago, RocketSimplicity said:

    I too bought KSP from Steam, so that doesn't appear to be the problem.

    Sadly, it doesn't work.

    Several friends of mine spent their money on this game because they had the wrong impression. I think we really need a demo that sticks around and is in clear sight on the KSP website. They shouldn't also pull it down once a new version for the full game has been released. 

    I think this is how the developers should do a demo:

    Theoretical Example with 1.7+ releases

    1.7: Can we develop a demo yet? No, we're working on BG DLC and 1.7.1

    1.7.1 Can we develop a demo yet? Not yet as we need to quickly fix bugs with this version and the DLC

    same for 1.7.2

    1.7.3: Can we develop a demo yet? Yes we can, before we start over with building 1.8

    1.7.3 demo is quickly made , and then 1.8 development begins.

    No demo for 1.8 and 1.9, but lots of new features have been added, and so the 1.7.3 demo wouldn't give a realistic impression on what the game was like now, so

    1.10: Can we make a new demo? Not yet as we need to fix bugs

    Hotfixes come, and then when the devs think 1.10 is complete, they make the demo.

    It's very unfortunate that the demo can no longer be obtained through ordinary channels.  However, it can still be found online without too much trouble.  For instance, if you put download ksp demo into Google, you'll get a bunch of results, primarily from people on this forum asking how to download the demo (lol), then the KSP website, steam, etc.  Ignore these.  Further down the list you find some third party downloads, and these are still functional.  Just pick one that's not too disreputable.  For example, I've never had a problem with softonic's files, but it's a bit of a chore to navigate through all the false links (that take you to ads instead) to get to those files. 

    I tried the demo from softonic; it worked fine, and my computer hasn't caught fire yet. 

  9. 1 hour ago, Polnoch said:

    Thank you guys for answers

    Another question. What people currently use as modmanager/modstore? CKAN? Or something new?

    What's wrong in the stock's implementation? 

    I don't remember too. I just remember that I still used not stock implementation. Maybe because it was not in the stock in that moment or because other reasons. Also I used kOS and kOS scripts...

    The problem is - I used realfuel mod. Maybe I have to avoid use it (to reduce amount of mods) I don't know.

    I still hear people talk about CKAN, so probably that is still the thing to use.  But honestly, it sounds like so much has changed that it might be worth considering starting from scratch:  play with the base game for a little while, and then add things back in, instead of deciding what mods to cut back on when you don't even know what it is they're replacing. 

  10. Just now, VoidSquid said:

    There's already a mod for this (one of my mods I don't want to play without):


    I might be wrong, but are you maybe talking about KER? KIS/KAS is about inventory and mounting/attaching parts during a mission, not dV or TWR readouts.

    See, that's the thing, I don't use any mods, so I'm just wildly flailing around when I try to answer his questions lol

  11. Whoa, relay network was new as of 1.4?  I must have bought the game right as they introduced it.  

    One of the biggest things for people that lived through the updates was that one of the Making History engines, the Wolfhound, had super OP Isp for an LFO engine, but they nerfed it somewhat so that doesn't matter to you.  (420 to 380)

    Honestly, I haven't been following the updates all that closely so I'm a bad person to try to help you.  But I'm really stoked about the updates that are coming soon!  2.5m SRBs at last (no more clusters of 4 kickbacks for me), being able to edit action groups while on a mission (and review what they even are!), and more.  

    I'm assuming that when you say KAS and KIS features are in the stock game now, you are referring to delta-V and TWR readouts being shown for each stage.  

    [edit:  I totally agree with VoidSquid:  while I struggle to think of huge, attention-grabbing changes (other than the expansions), there have been lots and lots of smaller, just-works-better changes, and it should add up quite nicely.  Oh, at some point they slightly changed Eve's atmosphere, but it might have been before you left and it wasn't drastic.]  

  12. 3 hours ago, Master39 said:


    If you know nothing of programming then, maybe you don't know if time could be better spent elsewere.

    VPL means Visual Programming Language, a Lego-like system where you put together visual blocks to program, it's meant for teaching children how to program and it's actually easier and more powerful than action groups to use.


    Just immagine a rocket instead of the Cat and the blocks sayng things like "When fuel=0 stage".

    As someone who doesn't know nothing but doesn't really know programming, that picture really helps, so thank you.  I'm still deeply skeptical of your "easier" claim, but "easy" I could buy.  More powerful goes without saying.  

  13. 2 hours ago, DStaal said:

    You forgot an important step: How KSP is going to figure out what the craft is doing.  After all, it could have a random collection of parts, producing and consuming a random selection of (possibly mod-created) resources...

    Programming what actions the ship is taking isn't enough to simulate that, you need a good guess on what each different module in the ship is doing, and how it adds up at each step of time.  Which would mean you need to simulate it.

    There are games which do this kind of thing, but you'll notice that they give you a selection of units that you can order around - each is then clearly defined, and the game project it better.

    My Excel experience suggests a potential solution by analogy to recorded macros.  I.e., you hit record, do whatever stuff, and Excel makes you some code that does that stuff with one standardized button press.  KSP doesn't necessarily have to simulate all your vehicles doing whatever activities in the background.  If KSP can determine what one "cycle" of activity produces and/or consumes and how long it takes, then it can just say "you get this much per day" and not sweat the details until you get back in physics range.  

    [edit: looking back at the conversation, this would not apply to rovers "scanning for resources" as I interpret the phrase, but it would work for fixed activities.]

    If this is determined by player activity that could lead to some interesting "speed run" gameplay incentives, which I'm not saying is either a good or a bad thing.  

  14. On 10/7/2019 at 5:45 AM, Master39 said:

    You misunderstood me, I was not talking about just exposing an API, programming must absolutely be in game.

    I was talking against custom written languages that are so popular in many games, K-Os would totally be ok if only it used a real language like Lua or Python instead of Kerboscript.

    Having a VPL on top of that would be awesome it could totally replace the action groups system with something more powerful without increasing the complexity, even having a system in place that writes the correct pointer in the editor when clicking on a part.

    This scares me, particularly now that we are on the cusp of actually being able to adjust them while on missions.  

  15. So I'm living in a cave and just heard about this and I'm super stoked about it!  But I do have one question about the thrust. 

    On 9/4/2019 at 5:02 PM, Maxsimal said:

    1700kn and 3300kn in vacuum.   They'll rattle some windows.

    Taking these numbers at face value would mean the Isp doubles from 1atm to vacuum.  [edit: or Rocket Witch could be right in the post below.]  This would be unusual to say the least for an engine intended for the launchpad.  I suspect that one of these is wrong; dare I hope that 1700 should be 2700, or is it that 3300 is 2300? 

    On 9/10/2019 at 2:38 PM, Rocket Witch said:

    So people have asked about thrust and gimbal, but what about Isp? Will stock vacuum SRBs ever be a thing? They're rare enough in mods as it is...

    On the other hand, a vacuum-optimized SRB would make some people happy...

  16. I'm here to drop a super specific wish that I doubt anyone else has posted, but I only checked the first three pages so far so let me know if I'm wrong. 

    I would like to be able to toggle the VAB/SPH to "Night Mode" and see how my stuff looks in the dark.  I sometimes put the floodlights on things and I'd like to see how effective it is without launching and timewarping. 

    Or maybe it's already in KSP and I'm just ignorant.  In which case, please cure my ignorance! 

  17. On 8/20/2019 at 5:11 PM, Nuke said:

    would be nice but some work would be required to make the kerbol system stable for at least long enough to complete the game. if it starts to fall apart after that, well that's cool too.

    This would certainly alter my perception of the kerbals and their motives!  Humans, too, would probably throw infinite money at maniacs willing to hurl themselves into space in horrifically slapdash vehicles if the incentive was the solar system disintegrating on a human timescale.  

  18. 5 hours ago, Dragon01 said:

    A nuclear tug blows every space-oriented craft larger than a probe out of water, because the Nerv is just that good. If you're roleplaying anti-nuclear activists banning it, then it's the Vector. Only landers and spaceplanes have more than one viable design, and that's mostly due to aerodynamics being a tricky beast. Admittedly, part of the reason for all this is that KSP's toy solar system doesn't even really need all that extra performance LH2 can provide, but with more places to get to, this will stop being the case. With multiple propellants, even lifter design becomes much more interesting. 

    I am really surprised that you consider the Vector with its 315 isp to be some kind of overpowered beast for deep space craft.  I'm honestly dumbfounded, actually.  For me the Terrier/Poodle/Rhino triumvirate reign supreme in space among the stock LFO engines, with Cheetah and Wolfhound adding to the mix from MH.  What about the Vector makes it superior to these engines in vacuum in your estimation?  

    For the NERV, I don't disagree nearly so much, but I still think you're overstating your case a bit.  Its weak thrust means multiple engines are needed for reasonable TWR on larger craft, which can be annoying and potentially design restricting.  For non-reusable craft, I imagine a staged LFO design might do at least as well as a NERV setup, though I must admit this is a bit outside my KSP experience as I have not done much yet with large, non-reusable interplanetary craft.  

    And there's also career mode to consider.  Do you use 6 or 7 NERVs at 10k each, or one Skipper and extra fuel?  

  19. 17 minutes ago, Signo said:

    The weight at take off was 93.5t, oxidizer was almost absent, I had a few spare for the fuel cells and just in case for that extra TWR burn with rapiers in closed cycle. 

    It's been a long time since I've seen the SSTOs topic popping around. I usually went for a K-prize or anything similar and then, depending on the feedback, I used to add the single thread. But that was just my way. And you know what? Useless flying saucers were more popular than crafts you could use during a career game. My flying saucer was "craft of the week" The Ajax maybe got 3 likes.

    Beware of the AYYs.

    Well, to be fair, I burst out laughing at that flying saucer, so craft of the week wasn't undeserved, lol.  I'd "like" your posts but apparently that feature is currently unavailable.  Thanks again.  The new version is at least as well balanced as the old one, lower stall speed, more dV but less weight, etc.  Sluggish to accelerate after liftoff but somehow still lifts off at similar speed, lol. 

  20. 9 hours ago, Signo said:

    From now on I will propose "my own opinion" and not the truth. KSP is the game we love because there are many ways to reach the same target.

    So, after this disclaimer I will try to point out what I think could be "different" in your craft and in your post. 

    Well then, here we go. The design is subjective as you say, obviously if it looks cool it will be more popular but imo operativity overrides coolness. I like the way you tried to address any issue you could find around with the proper onboard system. The 4250m/s range looks appropriate to reach Minmus for your first pit stop. But we miss a picture of it. You may be aware of the LAW: pic or it didn't happen. Moreover, if I may, "anywhere" is a bold statement and in this case it may look like a clickbait of some sort.

    From a "technical" point of view, I think you have too many rapiers and too few nervs. I usually build LF-only spaceplanes to save on dead weight.

    My old Ajax 122 had a very similar concept but I had 3 rapiers and 5 nervs. Pics below. (sorry for squatting, but you know, pic or it did not happen :D )


    Last but not least, there was a thread completely devoted to SSTOs, maybe you could post this craft there instead of giving it a single thread.

    Nevertheless I really appreciate the way you tried to explain the decision making process behind the craft. 



    precoolers ARE the intakes (at least to me) but sometimes you need just that little extra.

    Thank you SO much, from the bottom of my heart, for this wonderful feedback.  Firstly, thank you for letting me know whether the overall dV is appropriate (it is, yay!)  Secondly, thank you for warning me that the "anywhere" could annoy people who thought I meant it literally.  It's what I actually named the craft, but I will reconsider that and also think about what else to call the thread regardless of the craft name.  Thirdly, thank you for reminding me that people would like to see a picture of the craft at the promised Minmus.  I have to admit that the version I uploaded was still en route to its first Minmus landing (earlier versions, with medium TCSes had gone there). 

    But most of all, thank you for alerting me to the fact that a plane of this size could reasonably fly with that much less engine.  Three RAPIERs, wow!  I think that craft was somewhere in the vicinity of 104 tons based on your picture?  Significantly less than mine, but still—my eyes are opened!  I immediately tried to modify my own, and while the initial test of three RAPIERs failed miserably, four seems to have done the trick.  It handled like a pig on the runway, but it circularized with 2400 m/s left in the tank—without a nosecone!  (I noticed this lack while on my upper-atmospheric speedrun)

    As for where to post it, I am a bit confused—I thought individual threads were a common way to debut craft unless it was part of some kind of series or collection.  But I'll look at what you said. 

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