General Question Planet Gravity Question

[Trekkie]

How do you Adjust the Gravity of planets in the cfg?

When i am in an orbit around the specific planet the Orbit changes like the ship is under Acceleration when its not.



greetz Trekkie

 

[Loru]

Do you have non-spherical gravity sources enabled, or maybe you're still within the atmosphere?

 

[Trekkie]

Do you have non-spherical gravity sources enabled, or maybe you're still within the atmosphere?

that is disabled and the atmosphere is till 120 KM and it changes the orbit even in geostationary

 

[jedidia]

Two screenshots of the MFD with a before and after might be most telling, as it will give us all information at once, otherwise we'll just be asking more and more intricate questions about your orbital elements...

 

[Urwumpe]

that is disabled and the atmosphere is till 120 KM and it changes the orbit even in geostationary

How large is the effect?
Do you use a throttle or joystick?
Is the perturbation secular or periodic?


Remember: Sun and moon can still have an effect on your spacecraft even in low orbit, this here is not Kerbal Space Program.

 

[Trekkie]

and this is after 2 seconds at 10x speed its not in a stable orbit but it works the same

---------- Post added at 10:14 PM ---------- Previous post was at 10:11 PM ----------

How large is the effect?
Do you use a throttle or joystick?
Is the perturbation secular or periodic?


Remember: Sun and moon can still have an effect on your spacecraft even in low orbit, this here is not Kerbal Space Program.

well it kicks me out of orbit
no joystick or throttle

 

[jedidia]

and this is after 2 seconds at 10x speed its not in a stable orbit but it works the same

No, it's not a stable orbit at all... :blink:

I don't know Tagra IV, are you sure that you're already above the atmosphere threshold in pic1?

If this behavior shows only on your custom planet, posting the config file you've written for it might be a good idea.

 

[Trekkie]

No, it's not a stable orbit at all... :blink:

I don't know Tagra IV, are you sure that you're already above the atmosphere threshold in pic1?

If this behavior shows only on your custom planet, posting the config file you've written for it might be a good idea.

i know its not in a stable orbit but even in a stable orbit its being kicked out

EllipticOrbit = TRUE           ; assume unperturbed orbit
HasElements = TRUE             ; orbital elements follow
Name = Tagra_IV

; === Physical Parameters ===
Mass = 5.973698968e+24
Size = 3.35687e6                   ; mean radius
JCoeff = 0.01475               ; J2 coefficient for gravitational potential
AlbedoRGB = 0.00 0.70 0.70

; === Rotation and precession parameters ===
; ref: see www.orbiter-forum.com/showthread.php?t=8185
PrecessionLAN = 4.89539507
PrecessionObliquity = 0.02276340837
PrecessionPeriod = -307703725.6
LAN = 3.782814532
LAN_MJD = 51544.5
Obliquity = 0.05443758224
SidRotPeriod = 12500.3
SidRotOffset = 2.547801285

 === Planetary Mean Orbits ===
SemiMajorAxis = 38765831150.654
Eccentricity = 0.054
Inclination = 90.071841
ElReference = ParentEquator
LongAscNode = 2564.94786
LongPerihelion = 3.19212
MeanLongitude = 5.26393

; === Atmospheric Parameters ===
AtmPressure0 = 71e3          ; Pa
AtmDensity0 = 6.131           ; kg/m^3
AtmGasConstant = 274.12       ; ? specific gas constant [J/(K kg)]
AtmGamma = 1.3941             ; ? specific heat ratio c_p/c_v
AtmAltLimit = 120e3           ; Atmosphere limit [m]
AtmHorizonAlt = 70e3         ; horizon rendering altitude [m]
AtmHazeExtent = 0.000002           ; horizon haze extent
AtmColor0 = 0.8 0.9 1
AtmHazeColor = 0.9 0.8 0.7
AtmFogParam = 5e-5 3e-5 4e3
AtmFogColor = 0.9 0.9 1

; === Cloud parameters ===
CloudAlt = 4e3              ; altitude of cloud layer
CloudRotPeriod = 15e5
CloudShadowDepth = 0.166
CloudMicrotextureAlt = 5e3 20e3 ; 65e3 125e3

; === Data for the Visual ===
MaxPatchResolution = 7         ; highest sphere patch level
MinCloudResolution = 1 ; cloud layer from this resolution
MaxCloudResolution = 7 ; highest cloud resolution level

Tagra IV cfg

; === Configuration file for moon Nereid(Neptune) ===
Name = Argolis_Cluster
EllipticOrbit = TRUE           ; assume unperturbed orbit
HasElements = TRUE             ; orbital elements follow

 ; === Planetary Mean Orbits ===
;***cfgBatchDataCalculator
Epoch =  2006.81499999155
SemiMajorAxis =  1208512292999  ; in metres
Eccentricity =  -0.0801           ; 
Inclination =  -12.2211          ; 
LongAscNode =  1.84558393612589     ;??
LongPerihelion =  3.85613296299717  ;??
MeanLongitude =  3.305842814567608  ;??

; === Physical Parameters ===
; === From default Nereid cfg ===
Mass = 1.3e1			 ; Approx. Calculated using Phoebe's Density
Size = 625000e4
SidRotPeriod = 31116096645	 ; 360.14 days
SidRotOffset = 0
Obliquity = 0.51452              ; inherit from Neptune
LAN = 2.2                    ; inherit from Neptune

; === Visualisation Parameters ===
MaxPatchResolution = 0           ; use explicit mesh

Parent Planet

; === Configuration file for planet Darklite ===
Name = Tohvun_III
EllipticOrbit = TRUE           ; ignore perturbations
HasElements = TRUE             ; orbital elements follow

 ; === Planetary Mean Orbits ===
;***cfgBatchDataCalculator
Epoch =  2005.41409993155
SemiMajorAxis =  14985021225  ; in metres
Eccentricity =  0.0101           ; 
Inclination =  0.3502          ; 
LongAscNode =  1.84558393612     ;??
LongPerihelion =  3.8561329629  ;??
MeanLongitude =  5.91064281  ;??

; === Physical Parameters ===
Mass = 5.973698968e+24
Size = 6.05e6             ; mean radius org 
AlbedoRGB = 0.7 0.9 0.8

; === Rotation Elements ===
SidRotPeriod = 86164.09        ; 23h 56m 4.09s
SidRotOffset = 4.8956          ; rad(280.5) at J2000.0
Obliquity =  0.4092797095927   ; rad(23.45)
LAN = 0                        ; vernal equinox

; === Atmospheric Parameters ===
AtmPressure0 = 101.4e3         ; pressure at zero altitude [Pa]
AtmDensity0 = 1.293            ; density at zero altitude [kg/m^3]
AtmGasConstant = 286.91        ; specific gas constant [J/(K kg)]
AtmGamma = 1.4                 ; specific heat ratio c_p/c_v
AtmAltLimit = 95e3            ; cutoff altiude [m]
AtmHorizonAlt = 600e3           ; horizon rendering altitude [m]
AtmHazeExtent = 0.05           ; horizon haze extent
AtmColor0 = 0.61 0.8 1.0
AtmHazeColor = 0.75 0.9 1.0

; === Cloud parameters ===
CloudAlt = 4e3                            ; altitude of cloud layer
CloudRotPeriod = 2e5 

; === Data for the Visual ===
MaxPatchResolution = 7        ; highest sphere patch level

; === Ring Parameters ===
RingMinRadius = 2.578                   ; inner ring radius in units of planet radius
RingMaxRadius = 4.407                  ; outer ring radius

; === Visualisation Parameters ===
MinCloudResolution = 1                    ; cloud layer from this resolution
MaxCloudResolution = 8                    ; highest cloud resolution level

Neighbouring planet

then in orbiter it looks like this

 

[jedidia]

Mass = 1.3e1

I think I've got your problem right here... According to this, Tagra IV has a mass of 13 kg... That's nowehre near enough to keep anything in a stable orbit. In fact I'm very surprised you even get any kind of orbit, considering there's an earth-mass parked next to it.

 

[Trekkie]

I think I've got your problem right here... According to this, Tagra IV has a mass of 13 kg... That's nowehre near enough to keep anything in a stable orbit. In fact I'm very surprised you even get any kind of orbit, considering there's an earth-mass parked next to it.

:lol: i will check that out when i get home thanks!

The 13 kg mass is off the big thing which i want to have as little gravity as possible, code 1 and 3 are the codes for the planets

 

[jedidia]

I see... it's one of those contracted universe contraptions... I can't quite tell from the configs what "the big thing" is supposed to do, because it is indeed huge... what's the purpose of having such a huge object with almost no mass in there? I'm asking because I try to understand what the heck is going on here...

There's quite a few weird things in those configs, like for example the big thing having negative eccentricity. I don't even know what that results in mathematically... :shifty:

 

[Trekkie]

I see... it's one of those contracted universe contraptions... I can't quite tell from the configs what "the big thing" is supposed to do, because it is indeed huge... what's the purpose of having such a huge object with almost no mass in there? I'm asking because I try to understand what the heck is going on here...

There's quite a few weird things in those configs, like for example the big thing having negative eccentricity. I don't even know what that results in mathematically... :shifty:

The big thing has to represent an Nebula, which only has to make those 2 planets orbit, of which i know it needs mass to do so, im still experimenting with system building so if there are some weird things thats because i was trying to figure out what was going on or creating the effect on the orbits or planets