How would I go about launching 5 satellites into a 100km orbit?

[Teh_Miner101]

I know the question sounds pretty simple but I want to launch them 72 degrees apart from each other in a 100km orbit above Kerbin. I don't know how to calculate the launch window for each satellite so thats why I'm asking you guys to help me out here!

[Cykyrios]

My method (not the most efficient) would be to launch all five satellites, almost at random, on their orbit. Once they're up there, I'd fine-tune their orbits so they're roughly at the desired positions relative to each other.

The most efficient method would probably be a test flight so you know how long it takes for your satellite to reach its orbit. Using this and the period of its orbit, you could find the right time to launch the others. The only problem is that you need almost perfectly identical launches for this to work.

[olex]

I would go the blunt way. Use MechJeb to have each launch trajectory and time as similar as possible. Launch the first satellite, note how long exactly the launch takes from takeoff to circularization end. Wait the same time in orbit and measure how far along the orbit the first satellite progresses (or calculate the progression, should be easy knowing the altitude, velocity and time; or just take the degrees from the MechJeb launch autopilot window after an automatic launch). Launch the second satellite when the first one is 72°+measured angle away from KSC (with KSC being prograde from it), do the same for the rest. Profit!

[maltesh]

Do it in one trip. Build a spacecraft that can transport all five satellites, and deploy them one at a time

Take it up to that 100km orbit. It will have a period of 32 minutes, 39 seconds.

1. Deploy the first satellite.

2. Burn prograde to boost your apoapsis to 285.255 km (delta-V, about 127 m/s). Period will be about 39 minutes 18 seconds, or 20% longer than the 100km orbit's period.

3. Go around the new orbit once.

4. When you come back to 100km, circularize again. You are now 72 degrees behind the first satellite. Drop the second satellite.

Repeat steps 2,3, and 4 for the third, fourth and fifth satellites, then head back to Kerbin.

It should be noted though, that five satellites evenly spaced in a circular 100km altitude orbit over Kerbin are too close to the planet for any one of the satellites to have line of sight to any other of the satellites in the set. Kerbin's edge is 31 degrees below the horizontal at an altitude of 100km, and the angle to the next satellite in a 5-sat constellation is 36 degrees below horizontal.

Edited August 11, 2012 by maltesh

[Teh_Miner101]

In this case, the satellite will be too big to replicate 5 times on the same craft. I'll try what olex said later though and see if that works