Lowest maintenance ground coverage constellation

[ajburges]

So it is well known by now that precision orbits for a comm sat network are difficult. My understanding is that there is a precision switch making it impossible to align an orbit period to high accuracy.

Anyone know of a good formation with extremely high coverage that requires minimal upkeep?

I considered highly eccentric orbits, but those still come with bunching and that still results in blackouts.

I am currently considering a 5 satilite constellation. One satilite (likely a polar scan and science sat) will act as an alignment timer for a Draim tetrahedron. While sensitive to bunching, a Draim tetrahedron at least uses elliptical orbits and it's high altitude makes period adjustment easier. Fewer satilites means fewer manuvers to recalibrate. The timing sat allows me to mitigate the disadvantage of measuring relative mean anomalies of 90° by instead aligning to time to apsis to different timer orbits. Finally, blind spots are preceded by loss of a network link allowing clear signaling of when calibration is required. The only disadvantage I see to this solution is the lack of low dV delivery. Each sat will need to execute its own inclination and Pe lowering burns.

[bewing]

With low tech, I'd say 4 keosynch (roughly equally spaced, initially) and one sat each in a north and south pole molniya or tundra orbit should do the trick for a century or two.

With higher tech antennas, you put them as close to the SOI boundary as you conveniently can. The orbits are so slow at that range that you don't need to worry about drift for a few millenia.

 

[Norcalplanner]

With really low tech (two HG-5s per commsat) I'd stick with 4 in equatorial orbits, but at an altitude of no more than 700 or 750 km.  It's possible to get really high accuracy now with a good orbital readout (such as KER or MechJeb), as the Ant can now be thrust limited to 0.5 percent on the fly.  I got my equatorial satellites synced to within 1/100th of a second using a thrust-limited Ant. 

[ajburges]

Tech is a minor issue. I was able to do my Mun landings with either a HG-5 on the mother ship or just going in the blind with a pilot. DSN is a little OP at level 2 (compared to the parts you have).

I have RA-2 dishes which can talk to each other across most bodies SOI. This is sufficient for pretty much any ground cover network. The worst case is Jool and it's sphere of influence is only 25% greater than the RA-2 power (and Jool is already a special case with its numerous natural satellites). I plan for interplanetary communications will be handled by high power arrays (4+ RA-100s) in perpendicular polar orbits of each planet beyond any natural satellites. That would allow 50% signal to reach Eeloo even when Kerbin is in opposition and better paths will be available more frequently.

My research suggests that just jumping on and off rails can accumulate accuracy errors that can result in seconds of ark traversal per orbit in a synchronous satellite. That kind of error wouldn't allow networks to stay calibrated for centuries. The speculation I saw was that there is a change in floating point precision during that process. If that is true, then scale of the orbit would have minimal effect on the loss of precision.

[Blaarkies]

Drop a probe onto the mountains West of KSC. Equip this probe with about 3 HG-5's.
Send a probe with a similar configuration on an eccentric polar orbit, Pe at south pole, Ap as high as you can get it without losing comm. The dish right after the HG-5 will be enough for an Ap of 84Mm(edge of SOI). Make sure the Pe is 70km.

I have not experienced any blackout in the northern hemisphere. The polar orbit sat swings by Pe so fast(relative to the Minmus-month time it spends in the above the North pole) that I just have not had the bad luck of launching in that time yet. Even the darkside of the Mun gets a good connection when in orbit.

With default occlusion settings, this should even cover half the southern hemisphere aswell

[bewing]

2 hours ago, ajburges said:

My research suggests that just jumping on and off rails can accumulate accuracy errors that can result in seconds of ark traversal per orbit in a synchronous satellite. That kind of error wouldn't allow networks to stay calibrated for centuries.

Once you have them set, you never have to visit them again during your lifetime. Why would they ever come off rails?

[Tidus Klein]

You might consider this cheating but i would use the set orbit cheat in the debug menu, launch yoyr satillite get it as close to geosync as you can, then use the setborbit cheat to perfectly calibrate your orbit, rinse and repeat for the other 2 sats you need and bingo! Sat network wich should have 0 drift