Interplanetary commsat network advice

[ROXunreal]

What would be the cheapest, least time consuming network of interplanetary comm satellites? I'm talking about number of satellites and their orbits, not about satellite hardware, which I can figure out myself.

Would it suffice to put two of them in a highly eccentric polar orbit of Kerbin, in a way that when one is at Pe the other is at Ap? I don't mind not having signal in the odd chance that the Mun is passing by, it won't last long and the chance of it happening at a critical moment is rather slim.

[jarmund]

it won't last long and the chance of it happening at a critical moment is rather slim.

Hehe, famous last words waiting to happen.

On a serious note: I did what you described once, and I soon discovered that as the orbits won't be 100% the same, eventually one of them will start lagging behind, and the small gap will start getting larger. It'll work for a little while, but eventually you'll want 3 sats up there, especially if you also want to remain connected to KSC.

[Cairol]

If I were you, I would setup 3 aequatorial system-range com sats for coverage and 3 polar orbit inter-system com sats for connecting to KSC for every planet.

And at some point you will want to setup communication command centers at some of the planets to keep the signal delay down to a resonable value.

So connection uptime to KSC is no longer that important. (given you don't want to go ultra-hard-mode)

Setting up 3 sats is barely more effort than setting up 2 of them. So I always go for the increased com link uptime and deploy 2x3 sats per planet.

It will also help for ground missions with rovers.

With only 2 polar sats, a rover at one of the poles can be dead for hours.

[Jovus]

Also, if you're primarily worried about cost, combine launches. One big launch is cheaper than three medium ones, usually.

[ROXunreal]

I do already combine them

Thanks for the advice, I'll probably put up three for now and go from there.

Also sorry for posting this in the wrong forum, should have been in the question forum.

[godefroi]

May I humbly suggest: http://forum.kerbalspaceprogram.com/threads/113592-WIP-OrbitSnap-Keep-your-RemoteTech-commsats-in-proper-formation!

I use 4 sats in equatorial orbits around Kerbin, and 2 long-range sats in extremely elliptical polar orbits (pe ~100km, ap at the edge of SOI).

Another extremely useful tool is this one: https://ryohpops.github.io/kspRemoteTechPlanner/

Edited October 30, 2015 by godefroi

[monstah]

I do the 2-polar highly elliptical setup and haven't had any trouble with the moons. An alternative to it is using Minmus to park your relays: it's inclined orbit means it won't cross in front of Kerbin frequently; its low grav makes the orbit long period, and you can get the sat to hang around Ap for quite some time while the other one gets away from Pe.

[cantab]

I reckon one satellite in an inclined high Kerbin orbit will do the job, provided it can link to the rest of your Kerbin satellite network in RT, or to Kerbin itself in AR. The chance of Kerbin getting in the way is small, but if it bothers you add a second with an orbit 90 degree rotated from the first. The Mun causing trouble is even less likely, especially if you also have relay sats at the Mun. The bigger problem I think will be the Sun getting in the way, and the only way round that is going to be a relay in deep space.

[Vanamonde]

Your thread has been moved to the how-to section in Gameplay Questions.

[Snark]

Agree with cantab. For interplanetary relay purposes, you really only need one satellite, in a large circular orbit that's steeply inclined from equatorial. Kerbin's SoI has a radius that's a large multiple of the planet's; the chance of Kerbin or one of its moons getting in the way is tiny, and even if it were to happen, the outage would be brief. All you need to do is to make sure that the relay has good connectivity to the satellites in LKO or keosynchronous, which is pretty easy.

My network in late-career RemoteTech games generally looks like this:

- Low, reliable near-Kerbin network

- Interplanetary relay in very high Kerbin orbit, as described above

- Each explored planet gets a single high relay of its own, like Kerbin (that's usually the first thing I put in place)

The design of a high relay satellite is typically to be festooned with lots of antennas of varying ranges. My network is typically a star formation (with Kerbin as the central node), but l also add some cross-links (e.g. Moho and Eve connect directly to each other), so that if the sun ever occludes Kerbin, the network will automatically switch to a roundabout path.

The guiding philosophy is, don't let the perfect be the enemy of the good. Getting a rock-solid guarantee of total 100% reliability is exorbitantly expensive and time consuming-- you can get 95%+ for much, much less.

[celem]

As people have said, the lightning orbits are the cheapest in terms of time and dV.

Though my personal favorite is land-based deep-space listening. You launch a couple of large dishes sub-orbital on Kerbin and land them on the surface spread out. I usually go with 3, 1 left by the pad and two others launched around the planet a bit.

I tend to put similar ground relays on the inward face of tidally locked moons too.

[Stone Blue]

Just thought i would throw this out there, if you want to eliminate needing sats for Kerbin LKO, and want to expand ground control around Kerbin, there's a mod for that, its part of the Kerbin-Side suite of mods:

https://kerbalstuff.com/mod/1073/Kerbin-Side%20Ground-Control