Relay to connect kerbin with ike

[Space Nerd]

I'm playing in sandbox and want to send Bob to ike,is 3 synchronous orbit relays and 1 in sol orbit enough to always get signal? (I will use the biggest antenna)

Edited July 11, 2019 by Space Nerd
Added more content

[Pecan]

It's enough but possibly in the wrong place.

If the relays are in the plane of the solar system then there will inevitably be times when they are blocked from any other planet - by Mun, for instance.  Give yourself a different perspective by putting them in polar orbits and think of looking 'over' and 'under' the intervening bodies rather than trying to see through or around the clutter.

You may also like to consider a highly-eccentric polar orbit, with apoapsis near the limit of Kerbin's SOI and periapsis as low as avoiding collisions permits.  In such an orbit your relays will spend the vast majority of the time far above, or below, the system plane and have a view only possibly blocked by the sun.  You already know how to get around the sun :-)

[Guest]

You don’t need the one in Sol orbit. A level 3 tracking station will see the biggest relay antenna well past Eeloo. 

I usually put a constellation with one 15G antenna and two or three 2G ones in a polar orbit around Duna beyond Ike’s orbit/SoI. There will be one above Ike’s horizon almost all the time anywhere on the body.

[Geschosskopf]

9 hours ago, Space Nerd said:

I'm playing in sandbox and want to send Bob to ike,is 3 synchronous orbit relays and 1 in sol orbit enough to always get signal? (I will use the biggest antenna)

Howdy and welcome to the forum.

In my signature is a link to an old-but-still-valid introduction to KSP's comm system.  That will explain all reasons why you don't need to get overly complicated with your network but @Pecan has pretty well summarized it already :).

If you're sending a lone scientist, then I'm assuming you'll be returning the bulk of the data instead of transmitting, so you're primary concern is having a link so the probe core on the ship can handle SAS for the burns along the way.  Is that about right?  If so, then the 1st thing to understand is that you only need a link at all when you'll be doing those burns.  You can always wait a little while to transmit science until you get a link.

The best way to get this is to put a pair of the biggest relays you've got in highly eccentric polar orbits at both Kerbin and Duna, one going up and the other down.  This will always give you a link as far as the Duna system (unless the sun is between Kerbin and Duna) , over or under every planet/moon that could get in the way.  And this will also cover the bulk of the Duna system as well, plus all the interplanetary space in between.  The only blind spot would then be the back side of Ike near the equator when that's facing away from a direct line to Kerbin.  To fill this gap, put 1 (or 2 at most) small relays in medium-altitude equatorial orbits at Ike.  Then the link can come from one of Duna's polar relays to an Ike equatorial relay, and thence to the ship.

There is no such thing as a network that provides 100% coverage 100% of the time.  But with a fairly simple set-up like this, you can provide coverage everywhere and usually right when you need it.  You might have to wait a short time on the back side of Ike once in a while for the equatorial satellite to come over the local horizon, but this won't be very long and is easy enough to plan your burns (and any transmissions) around.

As mentioned, no matter how you set up your system, the sun will always come between Kerbin and whatever planet you're at somewhere along the way.  So when planning your flight, try to get to Duna before this happens, so you can grab your science and be ready to leave.  By the time the return transfer window comes around, you should have a clear shot home.

To avoid this worry, it's a good idea to put polar relays at every planet except Moho.  That way, you can almost always have a link around the sun.  This is especially important when you go to Jool because the size of that system means it takes months to explore, so the sun WILL definitely block the line from Kerbin at some point.  So any time you go to a planet for the 1st time, be sure to include a pair of polar relays in the plan.  Equatorial relays can wait until you actually want to land there.

 

 

[Space Nerd]

I'm not returning any science, just want to take Bob on a ride.

I know the biggest antenna have a range well past eeloo, the solar orbit one is just for when kerbin is blocked by the sun.

Thanks for all the help, I guess I will try to add more to my current relays(3 in a almost equatorial synchronous orbit and one stuck in keosynchronous transfer orbit, all has 100G antenna.)

I will deorbit Bob and send Jeb instead.

The relay will be done when I have time.

Edited July 11, 2019 by Space Nerd
Changed my mind

[Geschosskopf]

59 minutes ago, Space Nerd said:

I know the biggest antenna have a range well past eeloo, the solar orbit one is just for when kerbin is blocked by the sun.

Relays in solar orbit are essentially the same as having polar relays at the various planets.  They give you more possible paths around the sun when other planets are inconveniently aligned.  Nice to have but not really necessary.  If you launch a Sentinel mission, you might as well stick a relay antenna on it as well but I don't I don't go out of my way to populate solar orbit with relays.

A problem with putting things in synchronous orbits (as if at the Trojan points) is that they don't stay there.  You can't ever get the periods exactly right and even if you come close, floating point errors accumulate over time.  Thus, eventually the satellites will drift into the SOI of the planet they're sharing the orbit with and then get ejected higher and yon.  The time required for this depends on the orbital period:  possibly years in Kerbin's orbit, just a few weeks or months in Mun's orbit.  So it's generally better to put solar-orbiting relays in between the planet orbits to avoid this problem.

However, of more day-to-day concern is that relays in solar orbit are in the ecliptic plane so are vulnerable to being blocked by intervening planets and moons.  Thus, it's best to put them in somewhat inclined orbits so most of the time they're not QUITE on the ecliptic.  However, significant plane changes in solar orbit are rather expensive on dV.

[Space Nerd]

Yeah the solar orbit relay would be between kerbin and duna but I will use polar relays instead.