Deep Space Relay Satalite advice

[Dragonwarp]

I've started to work with probes, and I can't figure out a good design for a comunications satalite that can talk to probes on interplanetary missions (thank god for kerbal alarm clock). Specificaly, where they should go, and the antenna I should use. Any advice?

Edited December 9, 2017 by Dragonwarp
Can't spell

[Plusck]

The first ship you send to any other planet should include a relay capable of talking to Kerbin at all times, that you leave in orbit there. For Moho to Duna, that means it has to be the RA-15. For Dres to Eeloo, the RA-100. And you need the level 3 Deep Space Network at home, of course.

After that, the issue arises as to how to control subsequent craft during the transfer. And how to control craft if you lose the connection temporarily. Or in other words, how to optimise resources and ensure you have at least approximate control.

My simple solution: put a pair of DTS-M1 antennae on any craft that is going to go anywhere interplanetary on its own, and make sure the probe core can at least do all of the cardinal direction holds and ideally also hold the burn node direction.

The dual DTS-M1s allow you get a reasonable distance from Kerbin (from Moho to Duna as long as they are on the same side of the sun) and still have direct control. And if you plot your manouvre nodes and reduce your engine max throttle before getting too far from Kerbin,  they can do course correction burns using the minimal control you still have (turn to X direction, max throttle, zero throttle).

So with that as a minimum, you can get to your destination, capture, get back, even land probably. But you still need that relay at your destination if you want to do anything. Without the relay, you just have to wait half a year or more until planetary conjunctions bring you close enough (and again, only for Moho through to Duna).

Edited December 10, 2017 by Plusck

[Rocket In My Pocket]

I've been using a "Comm buoy seeder-system" where I send a large relay sat holding 3 smaller relay buoy's. When it arrives it first drops off it's 3 buoys in a triangular pattern either at semi-synchronous or synchronous equatorial orbit depending on the body, it then places itself in a high polar orbit.

I find this works pretty well, and gives good coverage for a pretty cheap cost, and low time investment.

Here's an early example at the Mun in my current career save. (Don't mind the over-done explanation picture, I saw someone else do the bubble-zoom thing and wanted to try my hand at it!)

Edited December 10, 2017 by Rocket In My Pocket

[Cpt Kerbalkrunch]

21 minutes ago, Rocket In My Pocket said:

I've been using a "Comm buoy seeder-system" where I send a large relay sat holding 3 smaller relay buoy's. When it arrive it first drops off it's 3 buoys in a triangular pattern either at semi-synchronous or synchronous equatorial orbit depending on the body, it then places itself in a high polar orbit.

I find this works pretty well, and gives good coverage for a pretty cheap cost, and low time investment.

Here's an early example at the Mun in my current career save. (Don't mind the over-done explanation picture, I saw someone else do the bubble-zoom thing and wanted to try my hand at it!)

Nicely, done. I think @Corona688's method is gonna catch on around here. It looks pretty cool.

Edited December 10, 2017 by Cpt Kerbalkrunch

[Spricigo]

A different approach is to not even bother with high coverage, just have a strong connection with KSC and plan your maneuvering to take place while you have Line of Sight. 

That could be better for a single mission, you just pack some extra fuel for the inevitable less than ideal maneuvers, but that may still be cheaper than sending several relays (and in any case, one of your relays need to be the first one)