Change the moon's orbit?

[reverend]

(in orbiter 2016) Is it possible to change the orbit of the moon? I'm just curious what it would look like if the moon orbited closer to earth... like 1/4th the distance, or even just for fun to see what it would look like if the moon had a circular orbit at say 6000km altitude...

I'm guessing this would probably have a weird effect on the earth's path around the sun, probably creating a significant wobble...

idk... just a random idea.

 

[Artlav]

Once upon a time... a scary amount of time ago... i actually did that: http://www.orbiter-forum.com/showthread.php?t=10818

Haven't checked the planet's orbit or anything like that, however.

 

[hutchison66]

Once upon a time... a scary amount of time ago... i actually did that: http://www.orbiter-forum.com/showthread.php?t=10818

Haven't checked the planet's orbit or anything like that, however.

yeah the Moon's orbit was much closer, before the Dinosaurs or even life when tides where a half mile high I think it moves away from the earth 2 inches a year

 

[ADSWNJ]

I assume if you had an infeasibly massive set of down thrusters on a mock ship, you could thrust the Moon retrograde enough to bump its orbit into a lower orbit around the Earth. It would definitely increase the wobble of the Earth around the new Earth-Moon barycenter. I'd love to see a scenario with the Moon much closer, as it would validate a ton of work I'm doing on Lagrange points.

 

[jroly]

It's pretty easy to change the Moon's Orbit in Orbiter. Try pasting over the Orbital elements and some other lines of code in Phobos.cfg into Moon.cfg in the configuration directory.

 

[reverend]

I assume if you had an infeasibly massive set of down thrusters on a mock ship, you could thrust the Moon retrograde enough to bump its orbit into a lower orbit around the Earth. It would definitely increase the wobble of the Earth around the new Earth-Moon barycenter. I'd love to see a scenario with the Moon much closer, as it would validate a ton of work I'm doing on Lagrange points.

I'm not sure that orbiter allows thrust to affect planetoids... i might be wrong on that but can any one else confirm this?

 

[boogabooga]

I assume if you had an infeasibly massive set of down thrusters on a mock ship, you could thrust the Moon retrograde enough to bump its orbit into a lower orbit around the Earth. It would definitely increase the wobble of the Earth around the new Earth-Moon barycenter. I'd love to see a scenario with the Moon much closer, as it would validate a ton of work I'm doing on Lagrange points.

I'm pretty sure that the major bodies run "on rails" through their own dll modules that account for real-world perturbations. I would expect the simulation to ignore thrust acting on the a body itself.

You might be able to go to the config file, remove the reference to the relevant dll module, and provide Keplerian orbital elements of your own choosing, but I've never tried.

 

[jroly]

That is with the Orbital parameters of Phobos. If you are landed on the moon and you apply a second of hover thrust, you will begin accelerating towards Earth.

 

[reverend]

That is with the Orbital parameters of Phobos. If you are landed on the moon and you apply a second of hover thrust, you will begin accelerating towards Earth.

Hmm. so does this mean that a hypothetical rock on the surface of the moon would just fly off towards earth... so basically the moon would come all apart if this were actual.

Was this in 2016 or 2010?

I tried with 2016 with no luck... It's weird... i copied all the phobos elements to moon.cfg, but the moon still has it's normal orbit...

maybe i missed something. i'll try again tomorrow, and if not, i'll paste my configs, maybe someone will see what i missed.

Edit: I see terrain so it must be 2016...

 

[Thunder Chicken]

 

[jroly]

I tried with 2016 with no luck... It's weird... i copied all the phobos elements to moon.cfg, but the moon still has it's normal orbit...

This is how I did mine

[SIZE="1"]; === Configuration file for moon Moon(Earth) ===
Name = Moon
Module = Phobos
;EllipticOrbit = TRUE           ; assume unperturbed orbit
;HasElements = TRUE             ; orbital elements follow

; === Physical Parameters ===
Mass = 7.347664e+22
Size = 1.738e6                   ; mean radius

; === Planetary Mean Orbits ===
;***cfgBatchDataCalculator
;Epoch =  2006.49555099247
;SemiMajorAxis =  9373718.185   ; by Chode
;Eccentricity =  1.67764797641549E-02
;Inclination =  .447317844099851
;LongAscNode =  1.45112328382648
;LongPerihelion =  6.65884410217624
;MeanLongitude =  7.0063164440015

; === Rotation and precession parameters ===
; ref: see www.orbiter-forum.com/showthread.php?t=8185
PrecessionLAN = 4.588488707
PrecessionObliquity = 0.4661704238
PrecessionPeriod = -826.1311277
LAN = 2.245404188
LAN_MJD = 51544.5
Obliquity = 0.01884736041
SidRotOffset = 0.8064220017
SidRotPeriod = 27553.83426
;SidRotPeriod (days): 0.3189101187
;SidRotPeriod (days - node to node): 0.3187870797
;Precession Period (years): -2.261823758
;Obliquity (deg): 1.079874207
;Ecliptic LAN (rad): 4.622012017
;Ecliptic Obliquity (rad): 0.4546193651
;Ecliptic SidRotOffset (rad): 2.021915467
;Axis RMS Error (deg): 0.8684982418
;Lat/Lon RMS Error (deg): 0.8608715885

; === Visualisation Parameters ===
TileFormat = 2
MaxPatchResolution = 15           ; highest sphere patch level
HorizonExcess = 0.015   ; prevent mountain tops beyond sphere horizon from disappearing

; === Fixed surface observation points ===
BEGIN_OBSERVER
Brighton Beach:Tower: -33.4375 +41.125 120
END_OBSERVER
[/SIZE]

---------- Post added at 16:18 ---------- Previous post was at 15:11 ----------

Actually it might work by just only changing the module name?

 

[boogabooga]

What if you comment out the module and uncomment EllipticOrbit = TRUE, HasElements = TRUE, and all the elements?