Could you please add an option to the rendezvous manager so it creates a fictive point in a synchronous orbit, that's on the same longitude as the target on the planet's surface. This would be kind of a merge between the landing guidance and the rendezvous guidance.

This would not work unless the point was precisely on the equator. Maybe an alternative would be to be able to define an orbit by what longitude it holds over and how inclined it is. Though you can do this yourself by marking the longitude if you want. I do think we lack the ability to schedule burns over specific latitudes and longitudes, or the ability to schedule burs at certain altitudes for more than just circularization burns.

Directions incoming:

If you don't know how to do this yourself...

1. Discover what orbit shape (circular @ what KM?) you need when inclined at a degree that takes you over the latitude you want. (would be perfectly @ geosync on the equator, more if you're more inclined)
2. Enter into circular transfer orbit on desired plane, Set maneuver to take you to desired altitude. Mark the longitude @ T=0 to the node, and @ t=0 to apoapsis. subtract the two and save the difference.
3. last flight with real payload. Enter the same transfer orbit as before, subtract the prior difference from the latitude you want to wind up at, and schedule your burn to start over the resulting latitude. Schedule a circularisation burn for the apoapsis, and you are now stationary over the longitude you wanted. If the location is not on the equator, you'll have to live with the satellite moving north and south.

He did only specify longitude, not latitude... In other words, for whatever your orbital inclination happens to be, getting into a synchronous orbit where you oscillate between plus and minus X latitude (approximately zero if it's an equatorial orbit) while remaining over a given longitude.

A synchronous circular orbit is going to be at the same altitude regardless of what its inclination is - the orbital period matches the planet's rotation period - so I'm not sure what you're talking about in number 1.

Before doing the transfer burn in number 2 to figure out the phase angle, you can do a quicksave, which avoids having to launch a new flight before number 3. Just quickload once you've reached apoapsis and calculated the difference in longitude, then do the transfer at the correct starting longitude.

Good advice either way though. And it does sound like a feature that wouldn't be hard to implement and could be handy for setting up things like satellite constellations, especially the first one in a given orbit.

One thing worth mentioning about sync orbits that is often overlooked - Precise altitude is not that important, but the orbital period is. It has to be precisely 6 hours (length of a day on Kerbin), and as long as it is, your sats will drift a bit back and forth, but will always stay in the vicinity of your target point.
To calculate a time for transfer orbit, make a transfer node to target altitude, note time to this new apoapsis, divide it by 6hrs (Kerbal's rotation period) and multiply result by 360° (or don't if you're smart enough to figure out that 6 hrs is 360 minutes, so each minute gives exactly 1° drift, so your time to Ap in minutes gives desired angle in degrees). Now you know your phase angle, so position node at desired longitude minus phase angle and there you go! Once you arrive at Ap, circularize and tune your orbital period to be exactly 6 hours - and you're done!

This would be very useful for stuff like RemoteTech 👍

For Kerbostationary (Geostationary) orbit, we can do it this way:

1. Put a imaginary craft with the targeted sub satellite point
2. Intercept the imaginary craft
3. Circularize

Such an easy way :)
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