How to build a Satellite Network?

[LaurieCR7]

Well, i spent more than $250.000 and i still doesn' t know how to build the Satellite Network and i need your help. If isn't much problem explain me with a step by step guide.

[VoidSquid]

Basically you want to setup a comm network like this:

https://wiki.kerbalspaceprogram.com/wiki/Tutorial:Setting_up_a_CommNet_system

 

Be aware that you'll need Relay capable antennas:

https://wiki.kerbalspaceprogram.com/wiki/Parts#Communications 

 

Tutorial - How to Create a Satellite Network with Evenly Spaced Satellites:

Resonant Orbit Calculator:

https://meyerweb.com/eric/ksp/resonant-orbits/

 

...or in-game as a mod:

 

Edited August 6, 2019 by VoidSquid

[Geschosskopf]

20 hours ago, LaurieCR7 said:

Well, i spent more than $250.000 and i still doesn' t know how to build the Satellite Network and i need your help. If isn't much problem explain me with a step by step guide.

There's another tutorial linked in my signature.  It says 1.2 but it's all still the same in 1.7.

The TLDR version is like this:

1.  You don't need 100% coverage 100% of the time.  You only need the network AT ALL on 2 occasions.  #1 is when you transmit Science!.  #2 is if you have selected "signal required for control" as an option when setting up the game.  This can be accomplished quickly and easily with the simple network described below.

2.  You only need a ring of kerbostationary relays if you did NOT select "enable extra ground stations" when you set up the game.  Having these turned on means you just have to draw a line back to anywhere on Kerbin, not just KSC.  If you don't have the extra ground stations, then you can only talk to KSC, which is facing away from your ship 50% of the time.  If that's the case, then you have to replicate the extra ground stations in space with a ring of relays around Kerbin.  Which is a pain so avoid this if at all possible.

2.  The basic network consists of a pair of the biggest relays you've unlocked in highly eccentric (as in, stopping just short of the SOI boundary), polar orbits.  One relay goes up, the other goes down.  They are also approximately 180^ out of phase with each other, so when 1 is near Ap, the other is near Pe.  Due to how they're fast near Pe and slow near Ap, both relays will spend the bulk of their time well above and below the ecliptic plane.   the pair at Kerbin and the pair at whatever planet you're at will allow you to talk over/under every intervening body except the sun.  Puting a pair like this at every planet (except Moho) lets you talk around the sun when it's in the way.

3.  The pairs of polar relays cover everything but the far sides of any moons of the planets they're at.  So, for farside operations, you MIGHT find it necessary to put 1 or 2 equatorial relays around the moons you're most interested in, and time your activities on the far sides for when one of them is overhead.  So the signal goes from the ship to the equatorial relay to the polar relay and back to the Kerbin polar relays.  But this is not always necessary.  It all depends on what you're doing there, and whether or not it can wait.

[LaurieCR7]

Ok, so, i think i need to decloup the Satellites in the Periapsis and there i fix the satellite orbit? Sorry if i don´t understand good, my natal speak isn´t the english.

[VoidSquid]

To achieve a triangular orbit, step by step guide:

1. Decide what orbit altitude you want to go for, and if it should be a polar or equatorial orbit. Let's for example say, you want a 500km triangular polar orbit constellation around Mun.

2. Build your rocket with three deployable relay antenna modules, which each should have probe core, a battery, solar panels, a small fuel tank, and a small rocket engine.  Launch it, and bring it to a 500km polar orbit around Mun.

3. Check the resonant orbit values at https://meyerweb.com/eric/ksp/resonant-orbits/ , the important data here are the orbital period of 4h:0m:18.1s, and the altitude of the apoapsis of that resonant orbit which is 795.979km.

4. Deploy your first antenna module, immediately go prograde with your main rocket and raise the apoapsis to 795.979km. I strongly suggest you orient your rocket to normal before deploying the antenna module to avoid potential collisions when raising the apoapsis after deployment.

5. Switch to the antenna module, enable the engine, and check the orbital period, which should be close to 4h:0m:18.1s. If the orbital period is longer, go retrograde and burn slightly to adjust, if the orbital period is shorter, go prograde and burn slightly to adjust. What is important here is to achieve the exact orbital period as close as possible, the actual values for apoapsis and periapsis are not that important (if you, for example, end up with a 505x492km orbit, that's perfectly fine).

6. Switch to your main rocket and circularize at the next periapsis (which is 500km, of course).

7. Continue with your 2nd antenna, same procedure as point 4 to 6

8. Continue with your 3rd antenna, same procedure as point 4 to 5

9. Enjoy your triangular relay setup  

Edited August 7, 2019 by VoidSquid

[Snark]

On 8/6/2019 at 12:08 AM, LaurieCR7 said:

Well, i spent more than $250.000 and i still doesn' t know how to build the Satellite Network and i need your help. If isn't much problem explain me with a step by step guide.

That completely depends on what you're trying to do.  "Satellite network" is a vague term-- there are lots of different situations that need different kinds of networks.  It's hard to offer specific advice without knowing what you're trying to accomplish.

So... could you explain a little?  For example, why do you want a "satellite network"?  What do you want to do with it?  What is your goal?  What is the problem that you're trying to solve?

[Geschosskopf]

9 hours ago, VoidSquid said:

5. Switch to the antenna module, enable the engine, and check the orbital period, which should be close to 4h:0m:18.1s. If the orbital period is longer, go retrograde and burn slightly to adjust, if the orbital period is shorter, go prograde and burn slightly to adjust. What is important here is to achieve the exact orbital period as close as possible, the actual values for apoapsis and periapsis are not that important (if you, for example, end up with a 505x492km orbit, that's perfectly fine).

I would add that getting as close as possible to a specific orbital period measured in tenths of seconds requires only TINY thrust.  I find that RCS is much more precise than a main engine.  And if you're using your carrier vehicle to circularize the relay probes before detaching them, then the relay probes don't need a main engine because they don't need to perform any maneuvers, just fine-tune the orbit they're already in.  So instead of a fuel tank and main engine, just use some small mono tanks and put a set of RCS thrusters on it, that can point backwards and/or forwards.  Then point the probe prograde or retrograde and use the forward/backwards translation controls to adjust your orbital period.

But having said that, in the long run, such precision is pointless due to floating point error accumulating while the relays are on rails, especially if you do a lot of warping at high rate while going to other planets.  No matter how perfectly you space out your relays to start with, within a few in-game months to years (depending on where you are), they'll drift out of formation, bunching up on 1 side and leaving a gap on the other, which defeats the whole purpose of making a ring of relays to begin with.

This is why I don't even bother doing this anymore.  I find 1 relay in circular orbit at a moon is fine for nearly all purposes.  I just wait until it's overhead if I need it for something.  Every once in a while, I need to do something  more frequently or which takes longer (like driving a probe rover any distance on the far side of the moon), in which case I toss 2 relays there with only approximate spacing.  But for like 99.99% of a spacecraft's life, it doesn't need to be in touch with the network at all because it's neither maneuvering nor sending science.

[VoidSquid]

2 hours ago, Geschosskopf said:

No matter how perfectly you space out your relays to start with, within a few in-game months to years (depending on where you are), they'll drift out of formation

With all due respect, but I disagree here: my earliest relay sat constellation was set in in-game year 2 around Kerbin, followed immediately by Mun. Game time now is 28 years, and the Kerbin relay constellation is still perfect, the Mun constellation needed some slight adjustments only because I did not meticulously set the orbital periods to the tenth of a second. Imo, it is imperative to be very precise with the orbital periods, it pays of on the long run. 

Edited August 7, 2019 by VoidSquid

[LaurieCR7]

Thanks for your help

[Snark]

9 hours ago, Geschosskopf said:

But having said that, in the long run, such precision is pointless due to floating point error accumulating while the relays are on rails, especially if you do a lot of warping at high rate while going to other planets. 

Well, it depends how carefully you match the periods. The stock game makes it tricky to get an exact match because it doesn't have a high precision readout for orbital periods, but mods can provide that. For example, BetterBurnTime will display a precision orbital-period delta display if you target another orbiting vessel and your period is somewhat close; this lets you match periods within a millisecond, without too much trouble. At that level of precision, it takes thousands of Kerbin years to drift significantly out of formation.

9 hours ago, Geschosskopf said:

This is why I don't even bother doing this anymore.  I find 1 relay in circular orbit at a moon is fine for nearly all purposes.  I just wait until it's overhead if I need it for something.  Every once in a while, I need to do something  more frequently or which takes longer (like driving a probe rover any distance on the far side of the moon), in which case I toss 2 relays there with only approximate spacing.

... but yeah, pretty much this, too.

Just saying that it's not too hard to make a long-term stable formation, if that's what someone wants. But yes, you make a good point that one can have a perfectly serviceable, practical comms network without needing fancy synchronization.

It's all a matter of what the player wants out of their network.

 

[Superfluous J]

10 hours ago, Geschosskopf said:

I find 1 relay in circular orbit at a moon is fine for nearly all purposes.

I like taking the first few "put a satellite around world x" contracts that come up, and slap a relay on each one. If you do 3-4 you have coverage almost all the time. 7+ and you don't even need to think about it. And you made a ton of cash for making your network. Bonus!

[Geschosskopf]

11 hours ago, 5thHorseman said:

I like taking the first few "put a satellite around world x" contracts that come up, and slap a relay on each one. If you do 3-4 you have coverage almost all the time. 7+ and you don't even need to think about it. And you made a ton of cash for making your network. Bonus!

Quite true.  Especially if you give them more dV than they need, which is almost always going to happen even with the smallest tanks you have available (unless you drain them).  The customer only cares about the 1st 10 seconds in the specified orbit.  Once the contract completes, you can adjust the orbit to suit your relay needs.

[Superfluous J]

43 minutes ago, Geschosskopf said:

Quite true.  Especially if you give them more dV than they need, which is almost always going to happen even with the smallest tanks you have available (unless you drain them).  The customer only cares about the 1st 10 seconds in the specified orbit.  Once the contract completes, you can adjust the orbit to suit your relay needs.

Naw 90% of the need in a relay is met just by the satellite being there. I leave them in the orbit requested.

[Snark]

12 hours ago, 5thHorseman said:

I like taking the first few "put a satellite around world x" contracts that come up, and slap a relay on each one. If you do 3-4 you have coverage almost all the time. 7+ and you don't even need to think about it. And you made a ton of cash for making your network. Bonus!

^ This.

I make it a habit never to launch anything to orbit without sticking some HG-5 antennas on there (it's available really early in the tech tree, so I have it by the time I'm going to orbit).

Given the number of miscellaneous launches I do, pretty soon there's a motley assortment of junk in random orbits all carrying around 14M of antenna power (i.e. what you get from a quartet of HG-5s), which is plenty to extend all around Kerbin out as far as the Mun, and gives reasonably high (random) coverage of the planet's surface.

[VoidSquid]

... enter OCD me here: I simply CAN'T do that  

Contract is contract, that's what I'm paid for, nothing more, nothing less. Idiotic me needs to setup the relay network by my own, i.e. w/o any "official" contract, but my own self-imposed contract. Self imposed rules.

Yeah, pretty silly, I know  

[Superfluous J]

8 hours ago, VoidSquid said:

... enter OCD me here: I simply CAN'T do that  

Contract is contract, that's what I'm paid for, nothing more, nothing less. Idiotic me needs to setup the relay network by my own, i.e. w/o any "official" contract, but my own self-imposed contract. Self imposed rules.

Yeah, pretty silly, I know  

Hey rules is rules. I have my own silly ones too For example, I won't move a contracted satellite once deployed (and won't complete multiple satellite contracts with the same satellite) unless someone later asks me to move it. For cash . But I'll happily make the satellite do more than they asked for.

[Geschosskopf]

8 hours ago, VoidSquid said:

Contract is contract,...

EXACTLY!  The customer only paid for launch and 10 seconds in his desired orbit.  A deal's a deal.  After that, it's my spacecraft.  If the customer had wanted the satellite to remain in that orbit more than 10 seconds, he should have paid me more  

 

[VoidSquid]

@Geschosskopf  

Anyway, we're getting more and ore off topic here.

I hope your question has been answered, @LaurieCR7? If not, or if you have any further questions, don't hesitate to ask, the folks here are happy to help  

[Hotel26]

On 8/8/2019 at 1:25 AM, Geschosskopf said:

I find that RCS is much more precise than a main engine.

Depending upon how you wish to deploy satellites, an alternative is to limit engine thrust to 0.05% for that final tweak.

My relay satellites use a Dawn for the final orbit circularization, allowing also subsequent, autonomous fine-tuning of orbital period to maintain spacing (has never been necessary yet), so 0.05% thrust from a Dawn is about as miniscule as you can get.  I use the KER "orbital period" in a HUD for millisecond precision.

@Geschosskopf thanks for the tutorial and particularly the idea about the eccentric, polar (Molniya?) orbits for the interplanetary comm!!  That's great.

Edited August 10, 2019 by Hotel26

[Geschosskopf]

5 hours ago, Hotel26 said:

My relay satellites use a Dawn for the final orbit circularization, allowing also subsequent, autonomous fine-tuning of orbital period to maintain spacing (has never been necessary yet), so 0.05% thrust from a Dawn is about as miniscule as you can get.  I use the KER "orbital period" in a HUD for millisecond precision.

Well, that certainly provides the necessary precision    But the ion engines are quite expensive and are fairly far along the tech tree.  What do you do earlier in the game?

 

5 hours ago, Hotel26 said:

@Geschosskopf thanks for the tutorial and particularly the idea about the eccentric, polar (Molniya?) orbits for the interplanetary comm!!  That's great.

Thanks!

A true Molniya orbit is a specific thing defined by specific orbital parameters.  Its focus is downwards, its purpose being to keep the satellite over a strategically important area as much as possible.  I don't speak satellite-geek well enough to know if "molniya" has become a general term for any highly eccentric, highly inclined oribt, even if its focus is outwards.

[Hotel26]

18 minutes ago, Geschosskopf said:

What do you do earlier in the game?

Me, sandbox.  Light fuse.  Go boom. 

Yeah, Molniya seems to have greatest application to GPS, but I think it's just highly-eccentric in order to "loiter" over an area.  This application might be similar except polar specifically to be above/below the ecliptic.  Of course, as you point out in the tutorial, nothing is perfect, because things are only generally in the ecliptic.

Edited August 10, 2019 by Hotel26

[Hotel26]

tl;dr:  here for those who are interested: List of Kerbin Ground Stations

So I've turned off "Extra Ground stations".  And am deploying a couple of polar RA-100s.  I got curious about ground stations and followed some of the arcs.  I had seen the one at Baikerbanur and thought it was just because it was a space center.

I've seen the one on the giant rim in e.g. Cupcake's videos but presumed that might have just been a mod.

So I took a MiG out to reconnoitre.  Found the crater rim location in the dark.  Flew on to this one, near what I call Flamingo Island...

Yup, guess I am still a 'noob'!! 

OK, so the question I now wish to posit is, 'is there a list of the skeleton set of ground stations with locations and names and also with the superset when you turn on 'Extra Ground Stations'"?  I've searched but not found...

                                                      

I'm also now very interested in the question of building ground relay stations and seeking advice or pointers to topics or KerbalX craft with guidance for how to do it correctly...

Edited August 13, 2019 by Hotel26