Project Orbiter Navigator

Mindblast

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Edit: Current Beta Version can be downloaded from http://www.nestadlinn.de/orbiter/downloads/OrbiterNav_0_5_3_9b.zip
Also please join the Beta Testing Social group for bug reporting or general feedback.

-------------------X8----snip---original post-------X8----snip--------------
Hi all,

over the past months i've been working on a new tool for planning interplanetary travels. I call it Orbiter Navigator for now. It has progressed quite well so far and i plan to publish a beta version in the coming weeks, so i thought i'd show you what i've got so far.
The basic idea is to use an external application to do all the planning in an easy to use 3d interface. The application communicates with an orbiter plug-in via TCP/IP.

This is what the application looks like right now:
mainform.png


When you connect to orbiter, the data of the planet system and the current vessel are imported from the running simulation and visualized in the 3d view. Currently the trajectory of the vessel is always shown sun-relative so a low earth orbit looks like this right now:

spiralorbit.png


I'm currently working on an option to set the trajectory reference body. The sun-relative view is quite counterintuitive when planning the earth escape or just earth-moon transfers.
The yellow dot is the position of the vessel. To change the view time you use the slider below the 3d view or the buttons beside it for smaller steps.
The Date controls to the sides of the slider are used to set the timeframe in which the trajectory of the vessel is calculated.
Currently the trajectory is calculated using Runge Kutta 4th order method as described in the orbiter technical note "Dynamic state vector
propagation" (dynamics.pdf).
The whole planning of maneuvers is following the approach of the old OrbiterNav MFD. You insert a maneuver, adjust the dv and the trajectory in the 3d view is recalculated accordingly. So it is an experimental approach to maneuver planning.. currently there are no helper functions like the Lambert solver in IMFD or things like that.
To help with the planning you can select planets or moons as target in the lower left. The 3d view will then show you the closest approach points to these targets. For example a mars transfer:

marstarget.png


Maneuvers are calculated as real trajectory segments, not impulse maneuvers. This also means that you can plan maneuvers for low thrust drives that last for days, weeks, months.. The only problem here seems to be the time compression in orbiter as the built in autopilots seem to have some stability issues with time compression above 10x. I guess i'll try to address this problem in the plug-in later by implementing an autopilot that can be used at higher time compression.. so far the plug-in just features a very simple MFD mode just showing the data of the next maneuver.

onavmfd.png


Thats about it right now. Let me know what you think.
 
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Urwumpe

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Great idea...looks like a more useful program for that than NASAs GMAT.

Can this also be used for calculating maneuvers in LEO and export the burn data as Space Shuttle MNVR PAD?
 

Mindblast

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Should be doable.. although currently i don't import other vessels from the orbiter simulation like ISS or satellites that would probably be needed as targets for planning maneuvers in LEO. This shouldn't be much of a problem though.
 

mc_

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Looks like this is the right thing :thumbup:

What about displaying the orbital speed direction for objects? It should make dealing with "reverse direction" satellites easyer.
 

garyw

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I like the look of this! I've had a play with GMAT as well and found it to be quite a complex beast.
 

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Project very looks nice. I have to try few slingsots with it.
 

Mindblast

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Ah right.. slingshots.. :) Look at this:

voyager2.png


My first attempt at recreating the Voyager 2 trajectory. Its not quite accurate compared with the data of the real flight. I guess its because i calculate the planet positions only using static orbital elements currently. This can be improved later.
 

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It seems that this could be used to plan trajectories among the byways of the interplanetary superhighway. Is this part of the capabilities?
 

Loru

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Ah right.. slingshots.. :) Look at this:
"pic"
My first attempt at recreating the Voyager 2 trajectory. Its not quite accurate compared with the data of the real flight. I guess its because i calculate the planet positions only using static orbital elements currently. This can be improved later.

Does this tool divide whole manuevers into steps nad provide nescessary info for mfd?

I mean like this:
1:Earth _> Jupiter Orbit Ejection Burn:
MJD: xxxx, BurnVector: X Y Z, Burntime: t
2:Jupiter Slingshot Burn
MJD: xxxx+xxxx, BurnVector: X Y Z, Burntime: t
3:Saturn Slingshot Burn
MJD: xxxx+xxxx, BurnVector: X Y Z, Burntime: t

and so on.

I think you know what I mean.
 

Mindblast

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It seems that this could be used to plan trajectories among the byways of the interplanetary superhighway. Is this part of the capabilities?

Hmm.. i haven't tried anything like this but as i understand it the interplanetary superhighways make use of the lagrange points. I would expect the trajectory calculations near Lagrange points to be accurate with this tool as it does basically the same thing orbiter does to calculate the trajectory. (solving the equation of motion using the Runge Kutta method as opposed to 2-body based methods like patched conics).

---------- Post added at 02:30 PM ---------- Previous post was at 02:28 PM ----------

Does this tool divide whole manuevers into steps nad provide nescessary info for mfd?

I mean like this:
1:Earth _> Jupiter Orbit Ejection Burn:
MJD: xxxx, BurnVector: X Y Z, Burntime: t
2:Jupiter Slingshot Burn
MJD: xxxx+xxxx, BurnVector: X Y Z, Burntime: t
3:Saturn Slingshot Burn
MJD: xxxx+xxxx, BurnVector: X Y Z, Burntime: t

and so on.

I think you know what I mean.

Yes thats basically what you plan in the tool, what i called a maneuver... a burn if you want. You use the tool to plan burns with time, vector and burntime and the tool shows you the resulting trajectory.
 

jedidia

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This looks a lot like the Interplanetary flightplaner Jarmonik had on the scratchboard but never got to finish...

There are two major questions that pop up for me:

1. Will it be able to handle custom systems, or will this only work in Sol?

2. Will it be possible to calculate low-thrust trajectories?

if there's a yes to both, this would easily be my "addon of the year".

One question on the developement side: Is there a special reason you make it a seperate app, and don't integrate it into Orbiter via a Dialogue Window?
 

Mindblast

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Yes to both. :) It is already able to handle custom systems, though the prediction of planet and moon positions only works well if they are on keplerian orbits.
And low-thrust trajectories can be calculated but as i mentioned the problem is doing the maneuvers in orbiter with high time compression. I once did a test flight with a 0.05 m/s^2 acceleration drive which involved 2 days of prograde burn. But i could only use 10x time compression most of the time in orbiter so it took a while to do the maneuver. :)

I decided to make it an external app mainly because I didn't want to fiddle with OpenGL within orbiter dialog windows, I used C# and XNA here. Also with an external app you can do the planning of maneuvers on a different machine. Might be an interesting feature for the virtual space agency guys.
 

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:woohoo:

looks like I'll be getting a rather unexpected birthday present this year!

But i could only use 10x time compression most of the time in orbiter so it took a while to do the maneuver.
No worry, there are workarounds, as for example shown by ITEATMfd (i.e. autopilots that "cheat" and keep the ship on a steady course by setting the heading directly instead of using the RCS thruster under high time accelerations).

I decided to make it an external app mainly because I didn't want to fiddle with OpenGL within orbiter dialog windows

After I have seen how Face implemented my project, that employs a complete 3rd party 3d-engine into a dialogue window, I'm pretty much convinced that there is nothing you couldn't put in there as long as you keep the threads apart. I probably could play X-Wing in an orbiter dialogue box! :lol:

anyways, there's only two real advantages when implementing it completely. The first is that you don't have to alt-tab when in full screen (which can lead to trouble at times), and the second one is that you don't have to manually enter your vessel data. Then again, since your sending protocols around, I assume (hope) that the properties of the current focus vessel get sent to the external program automaticaly, without having to type them in...
 
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fireballs619

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Fantastic Work! It'll greatly help me with planning, as I too found GMAT too complicated.
 

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Sounds good!
Especially it can plan low thrust maneuvers.I think it can help me to creat the dawn mission trajectory.
I also have a question:Can it make a slingshot like the Cassini mission?
 

Mindblast

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Hmmm Cassini... the second Venus slingshot would be a problem currently as the closest approach to venus would only be shown once.. i'll have to rethink that.
 

Moach

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man! cheers! this is looking AWESOME! - i mean something like this is exactly what we needed, i particularly appreciate the manner it hooks up into an MFD :thumbup:


now... i had in mind a similar concept, perhaps we could combine brains on creating something like this...
i envision an in-Orbiter utility (one of those ctrl+F4 things) that does exactly what you have there but inside the sim...
i reckon there's probably an insane heap of code that wouldn't sit too well with this adaptation, so by all means, i just offer this as a suggestion - but it would be tremendously convenient, and most appealing for new users to have this thing set itself up from inside the sim itself...

another alternative, is to keep your already working graphics code, and simply fire up that app as a child window of the orbiter process, this way, ensuring the window can be opened mid-flight without neither pausing the sim, or being forced into background...


or, you may also just ignore my ideas... whatever works best :p :thumbup:



either way, this project is a very AWESOME idea, and i very much support it! - if there's any part of coding in which you might feel like using some help, i'd be pleased to offer it
:salute:
 

FarOutInFernley

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Moach, i read your post and once you said CTRL+F4 immeadiately i thought of FSNAV. That was a addon that brought a decent map and route planner to fs2000 and fs2004. And im excited at the thought of having something like this for use in orbiter.
 

Moach

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:hesaid: - my thoughts exactly :thumbup:
 
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