Here is an orbit I have never seen before

[Roger Houston]

I've seen a bunch of orbits but never before one like this.  Does anyone know if this is really a thing or a KSP artifact?  Got into this pickle in the simulator designing a rocket for the Molniya Orbit mission in RP.

[jimmymcgoochie]

Principia?

[Snark]

12 hours ago, Roger Houston said:

Does anyone know if this is really a thing or a KSP artifact?

It's clearly a heavily modded install, and this doesn't look to me like an orbit that can happen in the stock game. Perhaps best to ask about it in the thread of whatever mod is doing this?

[OHara]

14 hours ago, Roger Houston said:

Does anyone know if this is really a thing or a KSP artifact?  Got into this pickle in the simulator designing a rocket for the Molniya Orbit mission in RP.

 Looks like you are on the right track.  This looks similar to the Molniya orbit shown on the Principia front-page (link)  as seen in an Earth-centered Earth-fixed reference frame, which is one of the plotting options that Principia provides. 

The Sun appearing to orbit the Earth in your image makes it clear that the plots are made in a rotating frame, so inclined orbits will look strange.

[magnemoe]

On 3/15/2021 at 4:33 PM, OHara said:

 Looks like you are on the right track.  This looks similar to the Molniya orbit shown on the Principia front-page (link)  as seen in an Earth-centered Earth-fixed reference frame, which is one of the plotting options that Principia provides. 

The Sun appearing to orbit the Earth in your image makes it clear that the plots are made in a rotating frame, so inclined orbits will look strange.

That makes sense, plenty of orbits looks weird if you see them from other frames of references. 
Low speed Tylo flybys is an example. 
Mars orbit seen from Earth is probably an better example as we overtake it

Edited March 18, 2021 by magnemoe