Mathematical and scientific calculations?

[VincentMcConnell]

I\'m trying to be more precise and realistic with Kerbal Space Program and use mathematical and scientific calculations (physics) to make everything in my game go perfect correct on the first actual mission.

Does anybody have any calculations they use with Kerbal that they can share?

[EDF]

Let\'s see...

We have DeltaV, inertia, orbital periods, semi major axis, TWR, etc.

And that\'s just from the top of my head.

[VincentMcConnell]

Let\'s see...

We have DeltaV, inertia, orbital periods, semi major axis, TWR, etc.

And that\'s just from the top of my head.

Formulas to calculate each?

[EDF]

Formulas to calculate each?

What do I look like? An astronomer?

[UmbralRaptor]

Wikipedia is actually an okay place to start. If you have a bit of a Math/Physics background already, I\'m partial to Fundamentals of Astrodynamics.

Basic(?) formulas that I find useful:

?V == Ve*ln(mi/mf)

Circular and escape velocities:

Vcirc == ?(?/r)

Vesc == ?(?/r)

Orbital energy:

E == v²/2 - ?/r (E<0 for circular and elliptical, E=0 for parabolic, E>0 for hyperbolic)

E == -?/2a (Circular and elliptical orbits only, I think)

? == m*G (Iff the object you\'re orbiting is much more massive than you are. This is always the case in KSP)

?Kerbin and ?Mün are in the KSP wiki.

semi-major axis and eccentricity stuff:

Pe + Ap == 2a

Pe == a(1-?)

?p == a(1+?)

? == (Ap - Pe)/(Ap + Pe)

Ap/Pe == (1-?)/(1+?)

T² ? a³ (and in the case of the solar system, T² = a³ if T is in years and a is in AU)

T = 2?/?(a³/?)

(? == 0 for circular, 0 < ? < 1 for elliptical, ? == 1 for parabolic, and ? > 1 for hyperbolic orbits. Granted, Ap goes to infinity for the last 2, and T becomes somewhat undefined...)

[N3X15]

I should mention that if you guys need to document this stuff, the copy of the official wiki I\'m hosting has math enabled.

[PakledHostage]

For what it is worth, I\'ve attached a PDF printout of the first few pages of the MathCAD spreadsheet that I\'ve been using since I discovered KSP last summer. It gives some of the same forumulas as UmbralRaptor but in a format that might be a bit easier to read.

Anyone who\'s keen could use these forumulas to set up their own Excel spreadsheet.

[RC1062]

F = ma... :-[

[Kosmo-not]

dV = I_sp*ln(m_i/m_f)

dV = change in velocity (delta-V)

I_sp = specific impulse ( I_sp = thrust / (mass flow rate of fuel) )

m_i = initial mass

m_f = final mass

This is the equation I use most often, especially when designing a rocket.

[Endeavour]

How is the mass flow rate of fuel found?

[vexx32]

Well... you\'ll need to work out the rate at which the fuel burns -- this is determined not only by the part\'s config file (the engine itself has a value for the rate at which it burns fuel), but also by the amount of thrust you\'re applying in-flight. This will only give you a value in fuel units per second or something like that. I think there was a thread somewhere which had a value for the mass of fuel per unit, and you can then use that to work out the mass flow rate.

[SmiteZero]

Not to be a put-down, but I think most of this is a bit above your head, Vince. Just use the tools given. They work.

The best understanding of things like mathematical formulas for me come from actually using them and playing with them in software. Taught myself trig so I could write orbital simulations, etc. I learned about gravity equations so I could bounce a ball or fire a projectile. It\'s also much more fun that way.

Partly the problem is because you\'re asking for too much. People can post equations all day but it will all be useless to you because you don\'t understand how they work and explaining exactly why stuff happens isn\'t something most people are likely to want to do (or be able to) and it still probably will only be of actual limited use and understanding to you anyway. Start more specific, and smaller. You need a base of mathematical thinking before you are able to reach greater understanding.

[VincentMcConnell]

Not to be a put-down, but I think most of this is a bit above your head, Vince. Just use the tools given. They work.

The best understanding of things like mathematical formulas for me come from actually using them and playing with them in software. Taught myself trig so I could write orbital simulations, etc. I learned about gravity equations so I could bounce a ball or fire a projectile. It\'s also much more fun that way.

Partly the problem is because you\'re asking for too much. People can post equations all day but it will all be useless to you because you don\'t understand how they work and explaining exactly why stuff happens isn\'t something most people are likely to want to do (or be able to) and it still probably will only be of actual limited use and understanding to you anyway. Start more specific, and smaller. You need a base of mathematical thinking before you are able to reach greater understanding.

No, I understand how they work, the issue is, there\'s very little information given in KSP, so to calculate each of these, I need to open up the cfg files and look at the part parameters. I was taught things like delta-V while attempting to make a solid rocket booster. (Didn\'t have the money at the time to buy the propellant.)

[Kosmo-not]

All the equations I have needed were easily looked up on wikipedia.