Apollo 13 movie orbit ?

[roarke]

I\'m mistaken or this photo taken by me from the movie is a different orbit than a orbit made with KSP ? I never got to the moon, btw. As i understand, when you are close to reaching the moon, in KSP, a new part, so to speak, of orbit (a new visual line of orbit) is made.

[Pleborian]

its kinda possible to do that, but it will look more like this (flatter at the mun end, also my skills with paint are rubbish at best ;P), given enough time and preparation I reckon someone would be able to do it picture perfect

[Vanamonde]

I\'ve done that kind of orbit by accident, but I think that the way gravity works in the game makes it harder to achieve. That path gradually transitions from a stronger influence by earth to a stronger influence by the moon, whereas in KSP you reach a hard boundary and just 'fall' from there. Wouldn\'t NASA\'s trajectory serve to help you shed the velocity of transit? As you approach the body from ahead, its gravity would slow you down, whereas Mun speeds you up as you overtake it from behind in a typical KSP intercept path. I think.

[HarvesteR]

This maneuver is called a Free-Return trajectory, and it should be perfectly possible in KSP, however, it takes careful aiming and some setting changes to visualize properly.

Also, that figure is using the Earth-Moon rotating frame, where both the Earth and Moon are static in relation to one another. In KSP\'s single-body reference frame, the figure eight will look different, because the Mun will be moving relative to Kerbin.

To see that sort of trajectory on the map, you\'ll need to tweak the settings.cfg file and set these lines like this:

CONIC_PATCH_DRAW_MODE = 3

CONIC_PATCH_LIMIT = 3

That puts the patched conic renderer in \'relative\' mode, and increases the patches-ahead draw limit to three, so you can see your exit trajectory after you leave the Mun\'s SOI.

Should be easier to do a proper free-return with those settings.

Cheers

[rkman]

I find that swinging by the Mun in such a way that i again end up in Kerbin orbit isn\'t all that hard, i suppose the careful aiming is in getting Kerbin orbit nice and low so that it\'s easy to perform aero breaking or whatever method of deorbit one prefers.

Should it look something like this?

(both Mun and Kerbin periapsis are at ~370km)

[Nomer]

@rkman.

Very nice,

I\'ve never encountered a purple orbit color though.

I guess its the orbit you\'ll be after the escape tradjectory with the current celestial body.

[rkman]

The purple orbit is the 3rd trajectory; after the escape trajectory with the *next* celestial body (in the screenshots i\'m still in the first part of the trip, on the way from Kerbin to Mun).

It\'s enabled by the lines for settings.cfg that Harvester provided.

[Majiir]

It\'s not perfectly achievable because KSP doesn\'t simulate physics the same way our universe works. In the real world, we always feel the tug of the Moon, no matter how far it is, and its attractive force increases as you get closer. In KSP, the Mun only exerts a gravitational force once you\'re within its SOI, which serves as an approximation of real physics. You can achieve a similar maneuver in KSP, but it\'ll never be quite as smooth.

[rkman]

On second thought i suppose it should not look like that, because i pass the Mun on the inside of its orbit, but the Apollo 13 trajectory passes on the far side of the Moon.

[Vanamonde]

Oops. I wanna switch back. What are the original patched conics settings again, please?

[YoshiFan501]

1 and 2

CONIC_PATCH_DRAW_MODE = 1

CONIC_PATCH_LIMIT = 2

[Vanamonde]

Thanks!

[Talisman]

Can someone explain what

CONIC_PATCH_DRAW_MODE

CONIC_PATCH_LIMIT

Does? How many draw modes are there? I\'m using harvesters settings and they\'re awesome, much better then the original, I can see where my entire journey will go!

[Vanamonde]

they\'re awesome

You liked it? I didn\'t find this helpful:

[UmbralRaptor]

Can someone explain what

CONIC_PATCH_DRAW_MODE

CONIC_PATCH_LIMIT

Does? How many draw modes are there? I\'m using harvesters settings and they\'re awesome, much better then the original, I can see where my entire journey will go!

CONIC_PATCH_LIMIT is the upper limit on how many conic section patches will be drawn. eg: 1 will only show your trajectory in your current SOI (compare with 0.13), 2 will show your current, and next, etc. There\'s little to no need for more than 5 at this time.

I\'m unclear on what the different draw modes do.

[rkman]

Can someone explain what

CONIC_PATCH_DRAW_MODE

CONIC_PATCH_LIMIT

Does? How many draw modes are there? I\'m using harvesters settings and they\'re awesome, much better then the original, I can see where my entire journey will go!

You explained it perfectly:

It\'s awesome, much better, helps you see where you are going.

[roarke]

Wow, so much help, thank you all of you !!!!!!!!!!!

[ModernArc]

Well that is certainly a cool orbit!