Th3F3aR

@mhoram Yes with v0 i meant Orbital-speed (Sqrt(GM/(Orbitheight+Planetradius))) or escape-velocity (Sqrt(2*GM/(Planetradius)))

As we both said now, same TWR = same dVDrag, i just wanted to give the explanation cause i have varius crafts that don't get the same TWR (like i don't have the standard TWR of 1,5 or 1,7 for every craft). For example i have the ones limited to 1,5 TWR, 1,2 TWR or 1,9 TWR, even 2,2 TWR even with 2,5 TWR (although everybody says your engines will die or something like that, dunno what that means ) That everything changes with FAR / NEAR is okay That's why i hope someday better physics will get stock

Yes, as mentioned decouplers are the things your missing The cleck-cleck sound by the way is the sound the game does when you are switching stages / at the last stage. You'll soon see that by using decouplers your Stages will be shown in hangar and on flight, if you get the right order your ship should fly like a boss

If the crafts are equal i matters of TWR, yes. But i assume you are not flying the same craft everytime? So drag varies for all crafts not having same TWR / acceleration, therefore a slight dragV change is possible.

as i learned this several days ago i give advice as far as i can vDrag results from v0/Apg Apg = A/g v0 - Escape or Orbit dV A - acceleration g - Gravity of Planet That should be quite correct although you should everytime keep in mind that this is so theoretical that you never can rely a 100% on it dGravity is calculated by GM(1/o1-1/o2) GM is a Gravitational Constant for Kerbin it is 3,53E+12 o1 is your starting Orbit (600km / 600000m) for Kerbin on Waterlevel o2 is your destination Orbit (Kerbinradius+Destinationorbit) Calc for a craft i made v0 = 2100,60 m/s (200km Orbit) Apg = 1,44 (a is 14,13m/s at start) dvDrag = 1458,16 m/s vGravity = 1212,78 m/s dV-Total = ~4600 m/s This is quite realistic and with a test i proved that it is also quite accurate But there is also another Method that gets you "worse" values, like calculating a Hohmann transfer from 0x200km Orbit (off-perigree) TO the delta-v map, im doing one for myself, and i think you are on the right track with your idea is a do it quite similar Hohmann to Mün encounter for example then hohmann for mün orbit and i got that somewhat around 846,5 m/s from 400km Kerbin Orbit to 100km mün orbit, which is also quite precise as i found out. hope i helped you

Ah waht a nice trailer, glad i have preordered it in August, can't wait to get it into my hands

I'd pop in with 10€ cause i'd luv to see Jeb on a mission! I can programm and i have lots of people that are able to do other stuff, anyways keep us in touch with whats happening!

10 Rules of Engagement with KSP by me: 1.Safety first! Don't kill Jeb, Bob or Bill cause u don't know how to build a Rocket, mount at least a parachute at the capsule. 2.Boosters are awesome and cheap, use them often to give the rocket the push she needs and also to save some liquid fuel for the mainengines. 3.Asparagus staging, learn it, understand it, love it 4.Spaceplanes != Rockets 5.Use struts, less wobbly ships are less breaky 6.Once in orbit, you are "halfway" to everywhere 7.Try sending satellites, probes at first instead of Kerbals, those guys don't like standing on dead rocks for ages... (Sorry Bob) 8.Have Fun with the game, create a set of missions that you want to do and do it! 9.Don't argue with Jeb, Bob or Bill, they are always right in terms of what they do or try to express...:huh: 10.Never expect to be a pro at KSP unless a pro tells you that you are a pro...

Well at least they don't implement one bit of the stuff i suggested for the trait system (yes i saw someone stealing my idea in this Thread ). Although i liked my idea -> http://forum.kerbalspaceprogram.com/threads/96849-Devnote-Tuesdays-The-Onward-to-0-26-Edition?p=1479409&viewfull=1#post1479409 But let's face the truth and wait for the exp result maybe it's really cool how the devs plan it. To the rest i must say, awesome load of work you managed to get done, i'm a programmer myself i can understand the pain of reworking code that works but isn't expandable anymore.

Nevertheless you still don't even need to know how much fuel in liters is in a tank, there is a wet weight and a dry weight on the wiki and there you get your fuel in kg (T/pounds) or whatever Also is the fuelconsumption given in kg and liters.

Basically a pretty damn good idea! But if we are to dig on the moon, think about its influence on earth, may nothing bad happen if we just make a hole through it

There is everything you need described on the link provided by mhoram and every part ingame got everything you need. When it comes to Burntime or the massreduction by fuelconsumption you have to dig a bit deeper on the wiki side. But keep in mind Fuel/Oxidizer 10/11 -> 180Liter Fuel / 220Liter Oxidizer (Example for the FL-T400), which basically means 1,25T wet Weight for that part (is given in KSP) and 0,25 Dry (is at least given in wiki) so you got 2 tons of "fuel" consisting of 180liters l-Fuel and 220liters Oxidizer. When you are at this point you got 2 choices: 1st: Dig deeper and calc fuelflow in liters 2nd: check out how many fuel your engines uses in kilogram (2000(Mass Fuell)/68,45(1xLV-T30)) -> Burntime And of course be more specific as i just threw out some info you might never need

@ Red Iron Crown Excuse my late response i had quite a lot of stuff to do this weekend. As i had now time to get to my computer i tried it out again. I must excuse, cause i reviewed the ship i used, the payload for that test was about 5,5 T so i made a mistake on that, i'm sorry cause i confused all of you I did it now with a 7,155 T payload and got the result, that your calculations were correct, i just made it to a 100km x 20km Orbit which is according to the 4500m/s needed and the 4300m/s avail, quite precisely. i wanted to post the screenshots i made and send you the craftfile, but actually i don't know how this works in this forum But i want to thank you very very much for claryfying, investing that much effort in my question and again excuse me for my bad memory

Its an Off-perigree so No periapsis, After circularisation and a Hohmann transfer to 400 km i have the 40% left. You See with the "normal" rocket equation there is not even a slight chance of success. But the testing shows that it works Greetings Th3F3aR

Correct ! I updated the weight now and i am (as before) in common with you at s3 and s2 Yup Yup! I don't get it , my excel spits out 920,67m/s... In fact the last Stage reaches Orbit with more than half fuel (sadly i can't remember the exact value) on a 200km apoapsis. I am sure that it was the stage fuel, maybe it was 40% but it was enough to get me to a escape trajectory to the Mün. But i'll try that again later and report the result.

Ah Okay then i my expression was wrong:confused: Edit: No Mods used, all Stock (No Far or Near) As you wish: Parts: Complete: LV-T30 -- 5x -- 215kN -- 1,25T FL-T400 -- 15x -- 2,25T Full -- 0,25T Dry FTX 2 -- 4x -- 50kg TT-70 -- 4x -- 50kg TR-18A -- 1x -- 50kg EAX 4 -- 8x -- 20kg Weight is given per each part, summing it up 40,61T SLS weight, add 7T Payload --> 47,61T Dry Mass of first Stage is 28,61T(6x FL-T400 Dry) SLS weight, add 7T Payload --> 35,61T Full Mass of Stage 2 would be 24,33T + 7T Payload -> 31,33T (Dropped 2 LV-T30 + 2 FTX 2 + 2TT-70 + 6 FL-T400 + 4 EAX 4 = 4280kg) Dry Mass of Stage 2 is 12,33T + 7T Payload -> 19,33T (6x FL-T400 Dry) Full Mass of Stage 3 would be 8,05T + 7T Payload -> 15,05T (Dropped 2 LV-T30 + 2 FTX 2 + 2TT-70 + 6 FL-T400 + 4 EAX 4 = 4280kg) Dry Mass of Stage 3 is 2,05T + 7T Payload --> 9,05T (3x FL-T400 Dry) Thats basically the staging, note that i calculated s3 with the Orbit Isp (370s) Ve ( 3633,60m/s) Correct me if im wrong but with these stage parameters i'll get s1 dV = Veatm*LN((40610+7000)/(28610+7000)) --> 919,43m/s s2 dV = Veatm*LN((24330+7000)/(12330+7000)) --> 1536,74m/s s3 dV = Vevac *LN((15050+7000)/(2050+7000)) -->1898,27m/s total dV = s1+s2+s3 --> 4354,43m/s As i said, it is Asparagus staged, dropping s1 after a Burntime of 35,07s, s2 after 58,46s and s3 after 101,4s. Burntimes are calculated with (AmountOfFuel(kg)/(AmountFuelConsumed(kg)*Engines)) -> Leads to Isp if divided by AmountOfFuel(kg) The calculation i used (as i saw in this Forum, which said it was for asparagus staging) just recalculates s1 + s2 like the following: s1 weight (6x FL-T400 + 2x LV-T30 + 2x FTX 2 + 2x TT-70 + Payload) 22020kg (the struts with 20kg are egligible) s2 weight = s1 weight dV s1 = 1856,39m/s = s2 dV Greetings Th3F3aR

No it was no Typo as i'm using the 3142m/s as Isp not the US 320s Therefore my g0 was already in the Equation I see, but the thing is, that i get a very lousy delta-v with this calculation for my Rocket (about than 4300m/s) but get into 400km Orbit with the last stage about 50% fuel left (approx 2000m/s) To tomf : Yes i forgott the Kerbin radius in this case Thats why i tried everything again: Basicly i started off with vo (200km) Orbit 2100m/s , then calculate the drag by Apg = a/g -> 1,692, the vdrag -> vo/Apg = 1241m/s and finally the Gravity loss Sqrt(GM*(1/r1-1/r2)) whic is at r1 = 600km, r2 =800km about 1213m/s, summing it up i get to the 4554m/s to leave Kerbin atmosphere and get an Orbit at 200km with this rocket. Back to the staging, if i calculate it as you mentioned Red Iron Crown i'll get for a ~7T Payload about 4354 m/s (and drag would get higher). So the 4554 to the 4354 -> No go, but i proved it wrong as i tested it 4 times and had the same result, about 50% left fuel on 400km orbit (instead of 200). With the other Staging calc where the mfull is just the stage itself 6 tanks+2engines+payload+struts etc i get that value i expierenced, quite precisely With this (even if very very inaccurate) calculations i have i am pleased, cause it workes. So im glad you all helped me, i have a long way to go but you all made it a bit shorter I don't wanna bother you guys but if you have intention to give me more explanation im grateful. Greetings Th3F3aR

Thank you for your honesty Rune, i do know that i dont have the mathematical experience and everything i wrote is assembled by google and different Websites tranig to explain the math behind the rocket. That even in reallife statistic are used is interesting, i didnt want to get exact values but wanted to get an approximate direction. I tried it many times and also with different rockets. I have a Feeling of what i Need to achieve my goals, but i wanted to get behind it, starting to optimize and reducing waste and failure. If you have sources that i could use to learn more id be very grateful, its also of interest for me to understand it better in the real world. To my values, i tried to orientate on Ksp sources like the Delta v map, therefore i was quite happy with what i got. And yes i forgot the 174m/s kerbin /subtracts to my delta v. Thank you very much Th3F3aR

Hi Nibb31, Thanks for the intel, i thought as this has something to with "rocketscience" it might fit in here, i assume i can't move this thread by myself? As my posts need to get passed thorugh by the moderators you missed my reply to the original post. I calculated the delta-v = Isp*LN(mFull/mDry) As i had learned now the asparagus Stages are calculated only with the weight of their parts. (and the payload?) All in all id led me to a needed dV of 6348,12m/s for a 400km Orbit and a achieved dV of approx. 6890,61 m/s what is more than sufficient and quite close to the experience i had on trying.

*Update*: Okay, i found out another way, maybe im wrong on this too but it seems reasonable: The delta-v needed for a Kerbin Orbit at 200km high is : Sqrt(GM/200km) -> 4201,19m/s (is this reliable?) The delta-v caused by drag is : vo/Apg | vesc/Apg -> 1433m/s | 2027m/s As i am Orbiting i assume the 1433m/s are the right choice ? This leads me to a total delta-v of 5634m/s (Sounds quite reasonable for me) I finally found out (hope this is right) that stages in Asparagus are not calculated like in "normally" staged rockets. With this i came to S1 2766m/s | S2 2766m/s | S3 1848m/s That leads me to a total delta-v of 7380m/s In this case i have approx 1746m/s left in my Stage 3 (94% of Fuel) This complete calculation sounds more like the experience i had in KSP but i'm still not sure if its accurate (Tolerance of 5% is allowed ) Can someone explain me if i'm doing anything wrong and what?? BTW: Engines are LV T-30 (215Kn/320s(atm)/370s(vac)) | Fuel containers FL-T400(2,25T/0,25T) Many Thanks Th3F3aR

Hi there, i am new to the KSP Forums, but an experienced Kerbonaut I am a facinated of rocket science since i play KSP and now started to plan my missions before i actually do them. I hope to get some help here and get the chance to also help. To my self, im a student (Computer Science) and live in Germany, i play KSP since the early days and never get tired of it greetings Th3F3aR

First of all thanks for steppin in here I know there might be maybe another thread open like this but after hours of googling and learning physics i basicly freak out now. To the Question: How do i calculate the amount of delta-v needed to get to "location X". What do i know: -I got the space ships specs -I got tons of equations to calculate stuff -I got no nerves left Starting of: My spaceship is a 3 Staged Asparagus SLS with a 7 T payload SLS Weight: Stage 40,61 T / 28,61 T -- Burntime 35s -- delta-v 1100,64m/s Stage 24,33 T / 12,33 T -- Burntime 58s -- delta-v 2135,78m/s Stage 8,05 T / 2,05 T -- Burntime 101s -- delta-v 4970,15m/s (vacuum) TWR is about 2,7 in every Stage delta-v complete (without payload) 8200,16 m/s Stagewise calculated with Isp*LN(Mtotal/Mdry) So far so good, i added the 7T payload and get following values Stage delta-v 912,59m/s (Loss is 17%) Stage delta-v 1517,5m/s (Loss is 39%) Stage delta-v 1848,10m/s (Loss is 63%) Seems legit as the payload is nearly equal to the 3rd Stages Weight --> output delta-v complete : 4278,19m/s Now i calculated around a bit with different Stuff, Hohmann transfers with 0 x 200km ellipse and 2nd burn 200 x 200 orbit -> delta-v needed approx : 4200m/s ?! delta-v for Kerbinorbit at 200km with Sqrt(GM/200km) -> 4200m/s i calculated loss through atmosphere -> approx 1212m/s | The amount of delta-v to lift it to 200km approx 1215,23m/s (2Ekin+Epot) and all these things but i never got the values i expected like 5900m/s - 6200m/s for kerbin orbit at 200km high (4500m/s lift of + escape atmosphere + loss through atmosphere + hohmann to circular orbit) So i tried to find out how i can calculate the delta-v for my rocket from 0-15km burn -- gravity turn to 45° burn to 200km -- turn to circularize at 200km burn to circular orbit. I couln't and the most sad thingy is i tried it in ksp with the 6 t payload and although my delta-v max was way below something like 4500m/s or 5000m/s i did the 400km circular orbit with approximately 40% of the last stages fuel left. I am really desperate now, i recalculated the delta-v's of the stages 4 times and still don't get it where my problem is. Can anyone help please? Many thanks Th3F3aR