Want to make some modifications

[JLF1961]

There are a few things I would like to do, and I am sure that there are folks on this board that will either A) Hunt me down and beat me with a large fish (see the movie Dogma) or B) have an alien race pick me up for study.

1) I want to add a large space station at the L1 point between the earth and moon.

2) I would like to change the orbit of the earth and moon by moving it half way to Mars.

Yes, I understand that any natural catastrophe that would actually cause such a drastic shift would probably throw the moon out its orbit with the earth and also the minor (sarcasm) seismic disturbances on the earth would probably result in a total extinction event.

However, the basis for item 2 is actually in a series of sci fi books I enjoy and I would like to set up a second copy of Celestia to model everything in the series, including one rogue planet, 126 high population/high tech worlds, 300 colony worlds and about 100 other earth type or near earth worlds.

I think that trying to do this would be far easier than say creating the Firefly 5 star system that another user was curious about.

[onetwothree]

You can start from https://en.wikibooks.org/wiki/Celestia

[selden]

There are a few things I would like to do, and I am sure that there are folks on this board that will either A) Hunt me down and beat me with a large fish (see the movie Dogma) or B) have an alien race pick me up for study.

1) I want to add a large space station at the L1 point between the earth and moon.

2) I would like to change the orbit of the earth and moon by moving it half way to Mars.

2 would have to happen before you can implement 1. The choices you make for implementing 2 would determine the techniques you'd have to use to implement the L1 station keeping.

Within Celestia, the orbits of the Earth and the Moon are defined by specifying highly accurate internal CustomOrbits implemented by using what's called "VSOP87 Theory". They can't work for your revised orbits. (See https://en.wikibooks.org/wiki/Celestia/Trajectories#CustomOrbit )

Your new definitions of Earth and Moon would have to "Replace" the Earth and Moon SSC declarations by your own. Doing this does not require any editing of Celestia's own solarsys.ssc. (See https://en.wikibooks.org/wiki/Celestia/SSC_File#Editing_Directives )

Your replacements could use simple Keplerian orbits or much more sophisticated "ScriptedOrbit" definitions. (See
https://en.wikibooks.org/wiki/Celestia/SSC_File#EllipticalOrbit_{_...parameters..._}
and https://en.wikibooks.org/wiki/Celestia/Trajectories#ScriptedOrbit )

Yes, I understand that any natural catastrophe that would actually cause such a drastic shift would probably throw the moon out its orbit with the earth and also the minor (sarcasm) seismic disturbances on the earth would probably result in a total extinction event.

However, the basis for item 2 is actually in a series of sci fi books I enjoy and I would like to set up a second copy of Celestia

You don't need to have a second copy of Celestia to implement these changes, although you can if you want. One implementation would be to create an "Addon" which you would move into Celestia's "extras" directory when you want to view them, them move it out when you don't. Indeed, implementing your changes as an Addon would make it easier to share your creation with other people. Such an Addon would be a zip of all of the files you've put in the extras directory, along with appropriate instructions and credits.

to model everything in the series, including one rogue planet, 126 high population/high tech worlds, 300 colony worlds and about 100 other earth type or near earth worlds.

What series is this? I'm an SF fan and would like to investigate it.

I think that trying to do this would be far easier than say creating the Firefly 5 star system that another user was curious about.

Maybe.

It depends on much information is provided by the series' author and how much you have to determine on your own.

I hope these comments help a little.