Red Iron Crown

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Everything posted by Red Iron Crown

  1. Red Iron Crown

    KSP memes Megathread

    Links broke when Dropbox killed public folders. All my memes in one convenient imgur album: https://imgur.com/a/qSex5Hz Two new ones:
  2. Red Iron Crown

    Confess your KSP sins

    Share the KSP-related things you really shouldn't have done but did, or things you really should do but haven't. Please commiserate if someone does the same as you, or discuss interesting sins, but please don't criticize other people for their confessions. And please don't post until you've confessed at least one thing. To get the ball rolling, my confessions: I am a mediocre pilot. I can perform almost all maneuvers by hand, but almost none of them very efficiently. I hardly finish any missions. I only actually execute maybe 1/5 of the missions for which I build ships. I love building and problem solving in the VAB and test flights, but I seem to get distracted by another design project before getting around to completing the mission. I've never watched a Scott Manley video. No longer true.
  3. Interplanetary transfer burns can be tricky, especially if the vessel has a low TWR (as is often the case when using nuclear or ion engines). Manouver nodes assume instantaneous burns, so if your vessel has to do a substantially long burn to escape they become inaccurate. One of the techniques to minimize that effect is to split up the single big burn into a succession of smaller burns (sometimes called "periapsis kicking"), but that introduces its own problems: - The time taken completing the interim orbits makes it hard to hit the transfer window precisely. - Ejection angle changes as Kerbin revolves around the Sun, so your periapsis may not be where you want when you make the final burn. To sidestep the above issues, I have applied Kepler's 2nd Law and the Vis-viva equation to precompute a simple series of small burns (300m/s or less) to complete before escape, applicable to any interplanetary transfer from Kerbin: Inital Orbit: 100km circular. Burn 1: Raise apoapsis to 658km, costing 300m/s of ΔV. Burn 2: At next periapsis, raise apoapsis to 2,250km, costing 300m/s. Burn 3: At next periapsis, raise apoapsis to 31,930km, costing 298m/s. Burn 4: At next periapsis, burn to transfer, costing 20m/s plus the remainder of the transfer burn. To hit the transfer window correctly, schedule the first burn for as close to 11 Kerbin days (66 hours) before the ideal transfer time as possible. To get the periapsis at the correct ejection angle, subtract 9.3 degrees from the computed transfer ejection angle for the first burn. It is more important to get the ejection angle correct than the time. Another set of burns for very low TWR craft using burns of about 100m/s, gives burn times of less than two minutes even with a TWR of about 0.1: Inital Orbit: 100km circular. Burn 1: Raise apoapsis to 240km, costing 100m/s of ΔV. Burn 2: At next periapsis, raise apoapsis to 419km, costing 100m/s. Burn 3: At next periapsis, raise apoapsis to 658km, costing 100m/s. Burn 4: At next periapsis, raise apoapsis to 987km, costing 100m/s. Burn 5: At next periapsis, raise apoapsis to 1,471km, costing 100m/s. Burn 6: At next periapsis, raise apoapsis to 2,250km, costing 100m/s. Burn 7: At next periapsis, raise apoapsis to 3,708km, costing 100m/s. Burn 8: At next periapsis, raise apoapsis to 7,409km, costing 100m/s. Burn 9: At next periapsis, raise apoapsis to 34,650km, costing 99m/s. Burn 10: At next periapsis, burn to transfer, costing 18m/s plus the remainder of the transfer burn. To hit the transfer window correctly, schedule the first burn for as close to 15 Kerbin days (90 hours) before the ideal transfer time as possible. To get the periapsis at the correct ejection angle, subtract 12.7 degrees from the computed transfer ejection angle for the first burn. It is more important to get the ejection angle correct than the time. In using these precomputed burns a few times, I have come to realize something that should have been obvious to me: Getting the correct semi-major axis is more important than getting the apoapsis correct. So ideally your Ap+Pe would be as close as you can manage to CalculatedAp+100km, especially for the final interim orbit. Limitations/Assumptions: Calculated assuming instantaneous burns, hopefully the vessel's TWR is high enough for reasonable burn times of the smaller nodes. Assumed no inclination change for the transfer. No normal/antinormal burn components are considered. The last interim orbit is higher than the Mun's orbit, an encounter with it could mess up your carefully laid plans. Useful tools: A transfer window calculator, such as http://ksp.olex.biz/ (simpler) or http://alexmoon.github.io/ksp/ (more complex), to calculate the ideal transfer window's time and ejection angle. There are also mods such as Transfer Window Planner or MechJeb that include such tools in game. Mods for precisely setting the ejection angle of a node, such as PreciseNode, KER or MechJeb. Finally, for those who would like to play around with their own values, here is the spreadsheet I used to calculate the above (xlsx format, please forgive the sparse formatting): MultiburnEscape.xlsx. I release this into the public domain, do with it what you will. Edit: regex was kind enough to expand upon the original spreadsheet and make it more general purpose, get it here: MultiburnEscapeExpanded.xls Questions, comments, or corrections are very welcome. Happy flying!
  4. The Curse client seems to offer some compelling features for keeping mods updated and synchronized, if it works as advertised it would be very useful. Back when the move to Curse was announced, one of the Curse people on the forums mentioned that the Curse client was being updated "this year" to remove ads and support KSP. The year is approaching its end, is there any update on whether this will happen? (If you are about to post some Curse hate, please don't bother and move along to another thread.)
  5. Red Iron Crown

    Why are you around the kerbal forum

    Came for the game, stayed for the people.
  6. Red Iron Crown

    Ask the Mods questions about the Forums!

    Oddly enough, that makes you more qualified for the job. Perhaps I'm not understanding, but isn't this something that the bookmark feature of your browser handles nicely? Most browsers support synced bookmarks across devices already.
  7. Red Iron Crown

    SAS: Hold Horizon

    That's not what Persistent Rotation does, to my understanding. It closes the loophole of rotation stopping during timewarp, but doesn't change reference frames or anything. It doesn't do anything with SAS as far as I know. That said, I haven't used it in a while, maybe the scope of the mod has changed.
  8. Red Iron Crown

    SAS: Hold Horizon

    That does just about nothing for the primary use case for this idea: atmospheric craft. (Also, I believe Persistent Rotation keeps rotation constant in the inertial reference frame rather than the rotating reference frame.)
  9. Red Iron Crown

    Partially air-breathing engines

    "Air augmented rocket" is the concept being described. Atmosphere is used as reaction mass but not combusted, which increases specific impulse.
  10. Red Iron Crown

    A new type of mouse

    6DOF controls have been supported in KSP for a long time, both for camera control and for attitude/translation. It takes some getting used to but is great once you do. Would be hard to justify $260 when a SpaceNavigator is about $100. I suppose bit of a premium for combining it with a conventional mouse is OK, but personally I prefer the devices to be separate.
  11. Red Iron Crown

    [1.3.0] Kerbal Engineer Redux 1.1.3.0 (2017-05-28)

    In your pic the currently active stage has no active engines in it, so...
  12. Red Iron Crown

    KSP Forum Stereotypes

    Thread removed. Reason: NONE. Fear me!
  13. Moved this thread over to Gameplay Questions.
  14. Red Iron Crown

    Curse Client/Steam Workshop?

    @SamBelanger Thread is eight months old, please watch for the little warning that the thread is quite old when making a post to prevent bumping old threads where the conversation is long dead. Closed.
  15. Red Iron Crown

    Ask the Mods questions about the Forums!

    My guess would be add-on releases, it's by far the most active section of the forum and many people create an account just to ask a question or provide feedback there.
  16. Red Iron Crown

    How to Attach Pictures to Posts and Comments

    You have to host your images somewhere other than the forum. Imgur.com is popular but by no means the only option. Once hosted get the URL for the image itself (must end in .jpg, .png, .gif, etc) and paste it into a post and it will embed automatically.
  17. Red Iron Crown

    My two cents

    My understanding is runway ramps slope downward, not upward. Outside of a few edge cases like STOL carriers and airstrips meant to train for them.
  18. Red Iron Crown

    Imgur albums broken ... again?!

    Workaround button removed since this seems to be working now.
  19. Red Iron Crown

    Don't Click This

  20. Red Iron Crown

    NASA VS SPACEX

    You can't check IPs without tracking them. By nature you have to record the IPs to check against.
  21. Red Iron Crown

    SSTO Question

    https://www.dropbox.com/s/owde581dj1o4pcv/SSTLR4.craft?dl=0 This was made in 1.0.4, so some things may have changed a bit. It's also pretty difficult to get to orbit in the first place as it struggles to break the sound barrier.
  22. Red Iron Crown

    Development Update for Consoles!

    Not particularly. I would recuse myself from moderating a thread in which I'm an active participant as a matter of course.
  23. Red Iron Crown

    Development Update for Consoles!

    Being a mod has nothing to do with it. I am a player and community member first, and I think the point I am trying to make about tone of posts is an important one. I am not upset by this at all, it would take far more than that. Not sure how my posts here are not "upstanding" in your eyes, but at any rate I'm not going to avoid sharing my thoughts because I help moderate the forum.
  24. Red Iron Crown

    Development Update for Consoles!

    Point to the foul language in my post, I'll wait. On this point we are at last in agreement. This is where we started talking past each other I think, as my original post that you seemed to find so objectionable merely asked whether the poster thought this course of action would lead to more developer communication or less. I made no judgement about whether being rude was justified or not, just that it is not productive.
  25. Red Iron Crown

    Development Update for Consoles!

    Your strawman was constructed here, when you replied to my post responding to another person by asking a question and painted it as if I were saying that I think people should be obligated to buy rotten produce. Which is not what I said or implied. Be rude if you like, I have not said that you can't. I am saying that it is counterproductive to the goal of better/more communication with the people to which you seem to want to be rude. I guess you need to decide which is more important to you: Venting angst at developers or having a meaningful interchange with them. It doesn't matter how justified you feel the rudeness is, the fact of the matter is that it discourages further communication. For what it's worth this is not a phenomenon unique to the console part of the KSP community. In the early days of KSP the developers were frequent participants here on the forum, kicking around ideas and discussing feedback with players. As the community grew that changed, as people started taking every offhand comment as a gold plated promise, being insulting and non-constructive in feedback; generally just making the forum an environment that did not encourage the devs to speak at all. So they mostly stopped, and now instead of banter and an inside look at how the game is developed we get carefully phrased developer notes that have probably passed through PR and legal departments before going public. To some degree I think this effect is inevitable as a community grows beyond a certain size, as the audience grows the Greater Internet <curse>wad Theory* becomes more and more relevant. Can't believe I have to straight-facedly argue that being rude is not a good thing. *This is one of the times when I wish I could link adult content here, but look for a Penny Arcade comic entitled "Green Blackboards (And Other Anomalies)" and you'll find what I'm talking about. John Gabriel's observation that "normal person + anonymity + audience = antisocial behavior" is as true today as when he posited it thirteen years ago, sadly.