Lynch

Firstly; Thank you everybody for their posts and replies for this entry. You guys made me enjoy the game more than I did before by inspiring and guiding me. I have led some experiments and came up with an optimum Launch Vehicle for Low Tech Career both Part, both Credit efficient ways at the same time! Using Gravity Turn Mod is essential to make accurate gravity turns. It is not cheating, nothing; I have never used MechJeb yet I know what it is, some people like that taste but I like to do my math even though Gravity Turn Mod does calculate your Angle and Starting speed, I wanted to be accurate, of course you can never be accurate but the lowest Total Burn I saw using my numbers were 2750 dV to orbit. However that approach can be deadly HOT and is not the most efficient scenario always so... I ran some excel spread sheets and foundout the most efficient gravity turn for 2 TWR is 28 degrees East right off the pad. I gave it some aerodynamic error path as 15m/s start for turn. With such an ascent path, you won't be worrying about passing 2400Kelvin and burning up while passing the thick part of the atmosphere. Using those values, with a rocket typically like this; You would achieve an orbit with 2795 dV. And lift a 80 ton payload for only 15,000 funds. That is around 6 Funds per tonnes! STEPS: 1) Have; Gravity Turn Mod Kerbal Engineer Mod 2) Aim for 2TWR and 3,500 dV Vacuum. (3,125 would do fine but I like a 10% safety margin) 3) Design so that 1st stage is your engine and 2nd stage is your payload. 4) Using Gravity Turn values of Turn Start: "15m/s" Turn Angle: "28degrees" Roll: "270" Apoapsis aimed 72,000m 5) As soon as reaching 30 seconds before Apoapsis, Abort Gravity Turn Mod. By now you will be in a 72x12 orbit 6) Use only 50m/s ish for circularising. 7) Detach your engine stage and you will be left with something around 300-400 dV if you used your safety margin, and use this dV for de-orbiting. 8) If you designed your engine stage recoverable, you will be recovering 100% of your Dry devices while only paying for fuel which is only negligible. Tomorrow I am hoping to post final version of my design on the front page of this post. My conclusions are; higher TWR does reduce your dV required while increasing design complexity and initial price since I am assuming you can find a way to recover every piece if you are a try hard person, while playing a career game having an initial money, losing that money by without recovering, running low on deltaV because of budget or even having not enough TWR can be stressing. For a person playing Career mode, 2TWR and 3,300 ish dV for a 1st stage part aren't dreams even in the low tech tree. Upon all that adding a full recoverable engine and fuel fuselage design can be really awarding. The only downside of this approach is getting to Apoapsis takes 10 minutes in x1 speed, so if you want to use your x4 speed you ll need a tight design as mine. Or MOAR STRUTS! Fly safer than Scott Manley and pull our Kerbal society forward to the future guys! I am sure hes out there building a god damn space elevator on Minmus by this time but mine is just a humble approach.

I am doodling with their code but Id like to know actual way of them calculating all these forces

First of all Id like to thank everybody above, I'd like to thank you for your answers, yet I know i might be running around the bushes; I am sick of this drag , I ll be going over those tools you showed but you are completely right. Im just trying to do right assumptions so that I get a good average of it rather than exact calculation. Yet, since I ll be excelling this I may go for exact numbers as you provided the tools

When doing gravity turns, do we have to use the Orbit prograde? Because im doing my calculations for the angles with the surface. What is the correct way of using those? I really need someone to tell me exact way of calculating Fdrag in kerbal space program.

aye aye ive been trying to solve this for 1 year, always got distracted by classes and other games actually My simplifications come from exactly those formulas. I have formulated effective gravity and the air density depending on the altitude and modeled an average temperature, I now need approximation of the Cd value for rockets with 1,25 2,5 and 3,25 parts

Well my launch is basically vertical for a distance to let the rocket balance itself. Then I want a gravity turn as low as possible. You are right though. you seem to be knowing this math, do you think length of the rocket affects the turn? also I dont want to just do the gravity turn I dont care about the time it take but as soon as I am on 70km I want to be in the orbit, I dont want to do a circularisation is this possible? taking these into consideration say I turn at X but is there such a theta angle that allows with correct thrusting to provide me such an ascent? Are there non kerbal free programs to simulate this?

Hi all, I am developing a mathematical model for gravity turn. Basically, I tried to get the Free Body Diagram of the rocket. There are 4 forces acting on the object, these are; Fdrag; FhorizontalThrust; FverticalThrust; Fgravity; By simplistic approaches, I chose my TWR value to be 2.00 and my mass to be 50 tonnes since all my vehicles tend to be between 0-100 tonnes and 1.5 - 2.5 TWR. After playing with the values, I constructed these forces in terms of height and mass. So thrust = 2mg = 1000 kN when we take a mass around 50 tonnes. Fdrag = 3.92 * Exp(-0.0001*h) kN FhorizontalThrust = 1000 * sin(x) kN FverticalThrust = 1000 * cos(x) kN Fgravity = 490.5 * (600000/(600000+h)) k In all these calculations h is calculated in terms of "meters" and x is calculated in terms of "degrees". The question is; After the launch of this vehicle, it is planned to go Vertical until it reaches h=1000m, as soon as it reaches h=1000m, it is planned to do a gravity turn to an angle of "x" degrees. What is the optimum angle so that the rocket continues its path and when it becomes parallel to the ground, it reaches V=2250m/s. My tests that involve try and error shows that in the latest version of the KSP we can orbit with around 2600 dV. The sooner the gravity turn, the better it is. Yet your rocket has to be designed fit for it. Here is my work on the paper; Fdrag was calculated simply by using excel trend line through datas taken from the terminal velocity. Fd = 0.5 * p * v2 * d * A p = e(-0.0002 * h) v = 98*e(0.0000973 * h) Coefficient of Drag * Area = 0.2 * 0.008 * mass (I know this value is for the old KSP, I would appreciate any further updates on this value). Fd = 3.92*e(-0.0001h)kN Fgravity = mg g = g0*(r0/(r0+h))2 mass = 50000 kg r0=600000m for kerbin g0=9.81 m/s2 for kerbin Fgravity = 490.5*(600000/(600000+h))2 kN

I did my calculations, and share my work; yet I am open to new ideas, I am willing to learn aswell from any person more experienced in this subject. Bring your flame down mate

True, im just trying my best to contribute to the society though; as much as i can. =)

*Design tip; build a thicker, shorter lander to avoid tipping off.

Atmosphere pressure force acting on RCS might be pushing it out with much faster pressure? A realistic approach?

Are you checking the batteries, power input output or the range of the antennas?

Struts decrease the FPS not lag, while increasing the part count. The FPS decrease is due to calculation of less physical bodies as they are now connected to each other. However there is also a limit to where the decrease can happen. After using overdose of struts the game does start to fail. Most advanced structures brough up need you to "Slap them on mostly" unless you use some special mods.

Imagine throwing a paper straw towards the sea, and imagine a paper straw having a stone tied at the end of it towards the sea. Now imagine just throwing an iron pipe towards the sea. Paper alone is so thin and weightless that it loses against the drag; yet anything fairly light requires fins. And gimbal issue is also correct.

Best regards to everyone on their answer to my post, this was a limited calculation, you can always over-calculate to take off from sealevel and turn it into a spaceplane, i prepare design calculations; you can advance them later on. I am preparing a new post up on calculations; for whom interested I await you on the links of the 1st post of this thread. =)