What is the significance of choosing a CLASS when making a ship in Space Engine? Is it just some trivial note in the info legend, or does it really make the ship behave differently?

I ask because I want to put an object (not a planet or asteroid) in orbit around a planet that will stay in place and still be there every time I open Space Engine, in spite of any time changes I might make....

thnaks;

Sorry for taking 2 weeks to reply to this...

The following instructions only apply to version 0.990 and later:

Class does not affect ship behavior, it is just used for sorting ships in the ship manager for now. If you want to put a ship in a static orbit, you need to do that via a catalog file, like for any other static object.

Here is an example catalog script from the HST addon from the Steam Workshop:
You should also set the spacecraft's type to Type to "StaticReal" (if you want it to be visible in the Planetarium) or "StaticGame" (if you want it to be visible only in Flight Simulator) in the .sss file. If you're using a model of ship that you also want to be able to spawn and pilot separately from the static object, make a copy of the .sss file and rename it and use the copy for the static object.

This is a tangential question to the above....how do you make a ship maintain a fixed height above the ground while touring a planet?  So let's say I want a ship to always be 1 km above the surface of a planet as it moves over the surface how do I do that?  And why are some ships better at it than others?  Is there a file I can modify to make it easier to do with a given ship?

Also, the ship must be placed in orbit around a catalog object — it will not work with a procedural generated world.

This is a tangential question to the above....how do you make a ship maintain a fixed height above the ground while touring a planet?  So let's say I want a ship to always be 1 km above the surface of a planet as it moves over the surface how do I do that?  And why are some ships better at it than others?  Is there a file I can modify to make it easier to do with a given ship?

There is no way to do that right now.

This is a tangential question to the above....how do you make a ship maintain a fixed height above the ground while touring a planet?  So let's say I want a ship to always be 1 km above the surface of a planet as it moves over the surface how do I do that?  And why are some ships better at it than others?  Is there a file I can modify to make it easier to do with a given ship?

There is no way to do that right now.

I don't know why, HD, but one of the Star Wars cockpits you made seems to be really good at it.  Not 1 km, but keeping it at under 10 km and also not crashing it into the surface.  I've tried to change the settings on so many ships but they invariably either crash or fly off into space no matter how much I fine tune the ships, but that one Star Wars fighter cockpit you made does exactly what I want it to do.  It's my all purpose cockpit, it's good as an airship and has a nice warp drive mode too, I want to import what it has to the other ships I like to use too.  I just wish I knew what settings or characteristics it has that make it behave that way and if there was a way to import those same qualities to other ships I like.  Is there a way to do that?

It does absolutely nothing special. Also you're now talking about flying it and keeping within a certain altitude range, which is not what you were talking about before; that was having the ship maintain an exact altitude above the surface at all times while flying. So now I don't understand what exactly you're trying to achieve.

It does absolutely nothing special. Also you're now talking about flying it and keeping within a certain altitude range, which is not what you were talking about before; that was having the ship maintain an exact altitude above the surface at all times while flying. So now I don't understand what exactly you're trying to achieve.

Ideally it would be to maintain the same height above the ground, but I'll settle for this as a compromise keeping it below 10 km, because at that height, I can still see some surface features while flying the ship and not having to constantly adjust the engines.  That is basically what I'm trying to achieve.  In a nutshell it is maintain an altitude where I can see topographic features on the surface without having to adjust the engines and not crashing into the ground or flying off into space and maintaining that for 12 hours (the duration of my videos.)  With the other ships, besides the cockpit you designed, they either fly off into space or crash into the ground within an hour or two if I dont keep adjusting the engines.  The reason I dont want to constantly keep adjusting the engines is I want to do other things while the video is recording the flight and may not even be near my system.  I'm not sure what it is about that cockpit that makes it so easy and smooth to do, while the other ships either keep crashing into the ground or flying off into space even if I make minute (one step) adjustments to the engines in the initial stages of flight.

You can just use the hold altitude autopilot, it will maintain a constant altitude above sea level (not above terrain though).

You can just use the hold altitude autopilot, it will maintain a constant altitude above sea level (not above terrain though).

Thanks, so this will work the same regardless of the ship I am using?
You are right about terrain, I've used this before and it works well in some ships but not for others for some reason.  One in particular called the Prometheus, it makes it repeatedly take off and crash back to the surface, over and over again lol.

It will work on ships with hover engines. If a ship is acting strangely, ask whoever made the addon why that might be. If it's not one that I made or one that comes with SE then I obviously can't help very much with it.

It will work on ships with hover engines. If a ship is acting strangely, ask whoever made the addon why that might be. If it's not one that I made or one that comes with SE then I obviously can't help very much with it.

Do the retro engines help with this at all?  I generally dont use them, I use the hover engines like you said and what I do is use the mouse wheel because that fine tunes them to increments of 1 and then I carefully set it to the minimum number that will hold me in place at  a stable altitude (usually 1 km above the surface to start out.)  Now, this doesn't keep me there of course it usually gradually increases the altitude.  I also sometimes use the main engines to begin with until I reach that altitude of 1 km and then I cut them to 0 or 1 depending on speed of ascent.  Once the altitude gets to around 10 km I usually cut back on the hover engines and either set them to 0 or 1 and wait to see if the plane is staying at a stable altitude.  I set it to 1 if its falling too quickly or 0 if it's stable.  With the ship I mentioned it would rise up and come back down repeatedly lol.  Does giving the ship a designation of "shuttle" change its behavior in any way?  I noticed the ships that were able to fly stably over a planet had this designation and this one didn't.  I went into its config file and changed the setting to shuttle but it did not change its behavior so I figure something else needed to be changed.  I tried to talk to the developer about The Prometheus but he doesn't seem to know why it behaves that way, all he could tell me is he copied the settings from another ship that was already in SE lol.

Does giving the ship a designation of "shuttle" change its behavior in any way?

Do the retro engines help with this at all?

No