[01:32:12] #KSPOfficial: mode change '+o UmbralRaptor' by ChanServ!ChanServ@services.esper.net [05:42:18] #KSPOfficial: mode change '+o UmbralRaptop' by ChanServ!ChanServ@services.esper.net [05:46:32] #KSPOfficial: mode change '+o UmbralRaptor' by ChanServ!ChanServ@services.esper.net [06:05:39] #KSPOfficial: mode change '+o UmbralRaptop' by ChanServ!ChanServ@services.esper.net [06:20:50] #KSPOfficial: mode change '+o raptop' by ChanServ!ChanServ@services.esper.net [09:05:38] hello [09:05:50] wlecome [09:06:05] finally, the bot doesnt react to this [09:06:08] i'm trying to learn some maths around ksp stuff but i fear i may have got some things wrong [09:06:15] can one of you check out my google sheet please? [09:06:21] its pretty simple stuff, i promise [09:06:31] orbital mechanics? [09:06:46] no, its simpler than that [09:06:56] ok [09:07:04] https://docs.google.com/spreadsheets/d/1SuehMhUAZnGrFQ6fZDtkYFtWVdXNA4L7DnC2RFVG2cQ/edit?usp=sharing [09:09:43] the calculations that dont say verified beside them are the ones i feel i may have done incorrectly [09:10:09] the acceleration, velocity and distance calculations are supposed to assume a complete vaccum, and earth's gravity applied [09:12:03] heh a meeting is coming up in a few minutes [09:12:07] nice sheet [09:12:24] is it for in-game calculations? [09:12:32] kind of [09:13:04] because the volume, thrust and isp is rdundant [09:13:25] ok [09:13:28] is anything incorrect? [09:13:29] the volume does not really matter for the game, and the other two are given by the engine [09:14:23] yeah [09:14:31] just thought i'd add them in because why not [09:15:02] i'm just unsure of the thrust/net thrust calculations and the accel/velocity/distance calculations [09:15:11] so i was wondering if i did them right or if they make no sense [09:15:22] the thrust and net thrust look suspicious to me [09:16:40] do you know how i could correct them? [09:18:29] also the speed and distance must necessarily be wrong, because the acceleration is exponential, since the rocket loses mass but thrust stay the same [09:18:43] that's a good point [09:19:00] https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation [09:19:38] the meeting started [09:19:45] be back later [09:19:53] ok [09:19:58] thanks for the help so far [09:54:28] lxb: so anyway, if the velocity wants to be the velocity at burnout, that must be the result of the delta v formula [09:54:44] ok, that makes sense [09:55:03] how would i make a rough estimation of maximum height from the velocity (assuming no atmosphere) [09:57:20] that, and basically the distance calculation seems to be harder, because you have a continuously changing acceleration [09:58:07] ok [09:58:16] would it be something like integration? [09:58:33] if it has a closed form somebody must have done it already [09:58:39] and they you have a formula for it too [09:58:53] if you have to integrate the v(t), then it can be harder [09:59:12] since i expect something exponential, it may turn out to be soemthing easy [09:59:36] now back to thrust and net thrust [10:06:22] both seem to be ok for me [10:06:56] ah i think i understand now, the bottom right part wants to be a result of a straight up launch [10:07:53] athough net thrust is only true in the very beginning [10:11:15] ok [10:11:30] so if this is true your velocity at the end should be something like delta-v - g*t [10:12:35] thanks for all of the suggestions, i'll try to do some more work on it tomorrow and hopefully it'll work out :) [10:12:58] it has been a while since i really needed to do physics :) [10:14:13] yeah im still in highschool so im not too knowledgable either thanks for the help [10:14:35] im gonna log off since its about 10pm here in nz, once again thanks [10:15:10] you could even test these in game. put the rocket to an airless body, in the cheat menu set gravity to kerbin, end launch straight up [10:16:01] that's a great idea [10:16:59] bye, hopefully i'll be back in the next few days [11:21:05] I wonder what I would have been like if I had access to KSP when I was lxb's age [11:22:59] well... considering I sort of wrote my own at the time, maybe only a bit more motivated to figure out all the math [11:23:00] i was learning orbital mechanics by playing elite in highschool :v [11:23:31] for me, it was Traveller that got me into orbital mechanics [11:25:47] i played elite 2 countless hours in high school [11:26:11] I played quite a lot of elite in university [11:26:15] taniwha: I can tell you what I would have been like... [11:26:39] nowhere near as much as I played Civilization, though [11:26:56] i played civ 1 too [11:27:01] cant buy it anymore [11:27:37] I think I have it somewhere still [11:27:51] it's on abandonia [11:28:04] Althego: https://archive.org/details/CIVILIZATION_201902 [11:28:21] or that [11:30:36] btw, I was really close to deriving Kepler's mean anomaly equation when I was 18, I just couldn't wrap my head around all the asin, asinh and log [11:31:47] took me another 25 years to realize that the log given for the integral was really just asinh in disguise (or maybe acosh) [11:44:18] I totally forgot how to play that game... [12:32:20] civ1? [12:32:37] first thing: don't use the mouse :v [12:34:30] first rule: do not talk about the fight club [14:13:21] Truga, are you talking about Civ or vim? [14:13:44] lol [14:14:12] :v could be a vim command [14:17:43] :q [14:17:54] lol [14:17:57] hehehe [14:25:26] what, is there a new shepar dlaunch? [14:26:07] it is already delayed [14:26:31] https://www.youtube.com/watch?v=O97dPDkUGg4&feature=youtu.be [14:26:31] YouTube - New Shepard Mission NS-13 Live Webcast [14:27:01] ah this is about that nasa autolanding camera thing, so they need clear images [15:07:06] Hm [15:07:31] This version flies very nicely, until you pitch up *slightly* too much [15:07:46] Then it snaps up instantly and both wings fall off [15:07:54] hehe [15:08:02] Action: FLHerne notes it in the pilot's manual [15:08:23] https://www.youtube.com/watch?v=TBcC8zqNjKk [15:08:23] YouTube - wings fall off of massive airplane(must see) [15:09:08] meanwhile isaac arthur [15:16:07] Althego: that's sad somehow [15:42:47] Ugh [15:43:14] I don't understand how people think it's appropriate to use clickbait titles for videos like that [15:44:04] the must see? that is annoying [15:44:18] but it is an old and known video [15:44:22] for wings falling off [15:44:29] Yeah [15:54:44] https://www.kerbaltek.com/users/Ezriilc/NOT%20water%20proof.png [15:55:15] hehe [15:55:20] not enough autorstruts [15:56:04] so many engines [15:57:58] I don't remember what I was trying to accomplish with that, but the pic was a keeper. [16:17:15] We’ve detected a potential issue with the power supply to the experiments. Launch is scrubbed for today. New launch target forthcoming. [16:17:17] no [16:17:43] so many Fs in chat [16:29:15] F [16:40:12] at least with such a small rocket they can probably repeat it soon enough [17:13:50] Action: flayer licks Althego [17:19:55] #KSPOfficial: mode change '+o raptop' by ChanServ!ChanServ@services.esper.net [17:33:45] #KSPOfficial: mode change '+o Deddly' by ChanServ!ChanServ@services.esper.net [17:48:05] hey can anyone help me with delta v because i`ve been looking at the delta v map and dont know how to read it [17:54:51] yeah, one moment [17:55:24] basically you have to add the numbers as you go along the lines [17:55:26] Fiddlekoof: Add them up from Kerbin to the destination [17:55:34] oh, good timing :p [17:55:37] but can omit those what you want to aerobrake [17:56:06] ^those, with a note that they can make it sound like a maneuver has more steps than it actually does [17:56:31] (eg: for low kerbin orbit to duna, you want to do a burn directly to a duna intercept) [17:56:38] well, SOI intercept [17:58:18] but wont the rocket be heavy with all the fuel tanks [17:58:58] you found the basic problem of rocketry :) [17:59:17] That's accounted for when you calculate Δv of the rocket [18:00:28] (but yes, the size of rocket scales exponentially with the amount of Δv you need, all other things being equal [18:00:30] ) [18:00:54] Which is why the ISRU stuff is really useful [18:01:42] ok i asked this because i needed to go to the mun and back and i can never go back [18:02:11] That's certainly doable [18:02:13] the deployed mystery goo experiment has a part of the description that says: never bring back to kerbin [18:02:37] never going back? done easily :) [18:03:09] Fiddlekoof: One way to make it easier is to do an Apollo and leave the return-to-Kerbin fuel in Mun orbit [18:03:22] Then you're not dragging it down the gravity well and back [18:03:36] but then you have to do a docking [18:03:41] Of course, then it's harder because you have to do the rendezvous [18:03:49] Yeah, but docking is fun :D [18:03:53] my mission is plant a flag on the mun and i don`t want to leave jeb [18:03:59] and docking is fun [18:04:16] no for the first time when you dont know what you are doing [18:04:22] Fiddlekoof: Use the most lightweight vacuum engine you have that gives your return vehicle sufficient delta-v and TWR. [18:04:25] FLHerne: eh, I'd argue that direct ascent is the easiest <_< [18:04:26] even nasa failed rendezvous the first time [18:04:37] but yes, just make it big and that's it [18:04:47] Jeb lands alone in a craft built arond a Mk1 pod and an LV-909 [18:05:08] Fiddlekoof: Basically -- keep dry mass and payload to the minimum, use the smallest that will do the job, make sure your trajectories are reasonably optimal [18:06:01] ok thanks ill try if i have anny more questions ill ask :D [18:06:26] Fiddlekoof: unlock maneuver planning [18:07:16] technically you dont need to [18:07:19] Oh, I forgot that was locked initially [18:07:37] Althego: You complain that docking is hard for newbies, and then say that? :p [18:08:06] burn when the mun rises, burn until trajectories intersect [18:08:09] that is really easy [18:08:13] docking is way harder [18:08:57] go pro :) [18:10:51] so basically if you have around 7000 m/s delta-v at start that should be enough to go there and back with an amount of margin. you an always add more if you are not sure of maneuvers and landing [18:11:05] for me i always burn several hundreds more than needed during the landing [18:11:42] ok [18:12:52] I usually adjust the altitude where I start the deorbit burn so it is a near suicide burn. [18:14:36] I go to a 10 km Mun orbit, do a test deorbit burn, look how much altitude I lose till 0 m/s, then set the altitude to that. [18:14:56] plus 50-100 m [18:15:13] IIRC [18:15:33] thank god theres a chat that can help [18:15:58] Thank Duna there are newbies who ask :) [18:16:11] funny, but actual nasa explanation of how to do the lunar orbit rendezvous helped me to do it [18:18:04] The free return one? [18:18:20] not the way there, but the rendezvous [18:18:54] Do an orbital insertion burn at Pe? [18:20:17] i really like this https://www.youtube.com/watch?v=7Fk2M-kLzmY [18:20:17] YouTube - LUNAR ORBIT RENDEZVOUS (1968) - NASA documentary [18:20:30] there are several such original videos, liek about the reentry [18:20:50] ill try buy im a newbie i got the game 2 weeks ago [18:26:48] Fiddlekoof: Don't worry too much about stranding Jeb in awkward places, you can always retrieve him later [18:27:15] It's sort of traditional :p [18:27:23] hehe [19:39:52] #KSPOfficial: mode change '+o raptop' by ChanServ!ChanServ@services.esper.net [21:05:34] Last message repeated 1 time(s). [21:05:34] Is there a convenient way to find out what blew up on my craft? [21:06:03] I saw a pretty explosion as something aerobreaked, but I can't find anything missing [21:06:23] (there's the mission log, but that only seems to be shown after crashing) [21:10:58] hit F3? [21:13:18] Hm, that doesn't show anything [21:18:08] Maybe a kraken exploded? [23:35:14] #KSPOfficial: mode change '+v eriophora' by ChanServ!ChanServ@services.esper.net