Building a Relay Constellation
Jun. 14th, 2018 07:35 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
the_sky_callsOn a previous flight, I put a single communication relay satellite into orbit. And while that extends the reach of the signal from the Tracking Station, it doesn't reach around to the other side of Kerbin. There will need to be three more.
Now, at this point in my career game, I have opened up the Tech Levl 5 Electrics node and the Probodobodyne OKTO probe core. Unlike the Probodobodyne Stayputnik, it has SAS flight stabilization and an internal reaction wheel so it can fly itself. The trick, then, is keeping it in sight of another relay satellite until it gets into its orbital position. It took some doing but I eventually got it there. If I was smart, I would have sent up another mission like the first with a relay satellite on top of a Mk1 Command Pod that way I wouldn't have to worry about communication shadows.
In either case, building you constellation involves first knowing where you want your satellite to be. Using a tool designed for the RemoteTech mod called the Virtual RemoteTech Planner for KSP, I designed a relay constellation with four satellites at a 777 km orbital altitude. The display shows that the distance between each of the satellites is 1,947,372 km. Launch your satellite to an 80 km orbit or so. Set the satellite already in orbit as a target and then build a maneuver node to take the new satellite up to that 777 km orbit either ahead of or behind the existing satellite by 90 degrees. Pointing at the intercept mark, it will tell you the distance between the satellite and the target. Shift the maneuver node forward or back until it reaches the 1,947,000 km separation.
Or you can just eyeball it.
That's what I do. A few score kilometers one way or another isn't going to make a difference so long as, once you circularize the orbit, you get as close to a 1.5 hour orbital period as you can.
Once the satellite is in the proper orbit with as exact a matching orbital period as you can manage, do it again with a third satellite. And then a fourth. Congratulations, you have built a basic and mostly functional relay constellation.
Mission Designation : ES-2
Rocket Model : EchoStar-5M C-I
Mission Objectives : Orbit 1,947,000 km ahead or behind ES-1
Total Mass : 14.7 tons
Delta-V : 5,707
Surface TWR : 1.16
Construction Time : 28 days
Launch Site : KSC
Launch Date/Time : Year 1, Day 309, 02:17
Now, at this point in my career game, I have opened up the Tech Levl 5 Electrics node and the Probodobodyne OKTO probe core. Unlike the Probodobodyne Stayputnik, it has SAS flight stabilization and an internal reaction wheel so it can fly itself. The trick, then, is keeping it in sight of another relay satellite until it gets into its orbital position. It took some doing but I eventually got it there. If I was smart, I would have sent up another mission like the first with a relay satellite on top of a Mk1 Command Pod that way I wouldn't have to worry about communication shadows.
In either case, building you constellation involves first knowing where you want your satellite to be. Using a tool designed for the RemoteTech mod called the Virtual RemoteTech Planner for KSP, I designed a relay constellation with four satellites at a 777 km orbital altitude. The display shows that the distance between each of the satellites is 1,947,372 km. Launch your satellite to an 80 km orbit or so. Set the satellite already in orbit as a target and then build a maneuver node to take the new satellite up to that 777 km orbit either ahead of or behind the existing satellite by 90 degrees. Pointing at the intercept mark, it will tell you the distance between the satellite and the target. Shift the maneuver node forward or back until it reaches the 1,947,000 km separation.Or you can just eyeball it.
That's what I do. A few score kilometers one way or another isn't going to make a difference so long as, once you circularize the orbit, you get as close to a 1.5 hour orbital period as you can.
Once the satellite is in the proper orbit with as exact a matching orbital period as you can manage, do it again with a third satellite. And then a fourth. Congratulations, you have built a basic and mostly functional relay constellation.
Mission Designation : ES-2
Rocket Model : EchoStar-5M C-I
Mission Objectives : Orbit 1,947,000 km ahead or behind ES-1
Total Mass : 14.7 tons
Delta-V : 5,707
Surface TWR : 1.16
Construction Time : 28 days
Launch Site : KSC
Launch Date/Time : Year 1, Day 309, 02:17
