Perfect Orbit?

[Fett2oo5]

Wow, I wish I came across this thread a couple weeks ago, I wouldn't have put myself through all that torment.

Yes, I am a stickler for accuracy so I've been trying to get my Sats in exact (as the instruments read) GeoSynch. At the time I didn't think to use a low power engine, so they have a Rockomax 48-7S. I realize now I should have used a low power engine so the burns wouldn't be so intense.

I ultimately gave in and used Mechjeb to help me. It got me to within ± 50 meters. Then I used it to plan the nodes and I did the burns myself.

After hours, yes, hours (usually 2 hours per satellite) of trying to get it perfect the best I could get was ± 5 meters. 2868750m ±5.

As stated above the Ap, Pe will change as the Sat would rotate, which was frustrating.

Now that I know I don't have to be that accurate, I think I will enjoy the game more.

If anyone wants to be very accurate I would suggest a low power engine, as well as saving before each adjustment burn that way you don't have to wait until another point in the orbit to try again or undo any causes from burning too long.

From now on I'll use a low power engine, try to get within 5 meters for maybe 5 tries and then just live with where I end up.

Edited August 14, 2013 by Fett2oo5

[sgt_flyer]

when i need a circular orbit, i usually try to get under 1km difference between AP and PE - generally end up between 500m and 1km difference, but i don't bother to go further, it becomes too unstable the nearer you get from a 0m difference (except for geosync, i usually try to get even lower, just to try to minimize the satellite's drift.

anyway, the various space agencies use margins of error when setting their satellites orbits. plus, some satellites do have ways to correct their own orbits, should the need arise. (it's costly enough to get them up there )

Edited August 14, 2013 by sgt_flyer

[Thomas Cook]

My closest circular orbit was with 150 meter difference or so between periapsis and apoapsis.

Having to yank the prograde and retrograde nodes beyond that point was way too sensitive.

Maybe manually fiddling with very tiny engines during flight might do the trick?

[blizzy78]

Wow, I wish I came across this thread a couple weeks ago, I wouldn't have put myself through all that torment.

Yes, I am a stickler for accuracy so I've been trying to get my Sats in exact (as the instruments read) GeoSynch.

The funny thing is, a synchronous orbit is not so much about exact apoapsis and periapsis, but about an exact semi-major axis. You could have saved yourself some more time

[RoboRay]

Exactly. My geostationary satellites have a couple of km difference between their Ap and Pe and it doesn't matter a bit. It's the exact orbital period (or SMA, depending on how you look at it) that matters, not a precisely zero eccentricity. You need to be fairly close to zero to prevent your satellite from visibly wandering back and forth across its parking spot, but a few hundred meters of longitude oscillation is meaningless.

Edited August 14, 2013 by RoboRay

[Diche Bach]

Wow, I wish I came across this thread a couple weeks ago, I wouldn't have put myself through all that torment.

Yes, I am a stickler for accuracy so I've been trying to get my Sats in exact (as the instruments read) GeoSynch. At the time I didn't think to use a low power engine, so they have a Rockomax 48-7S. I realize now I should have used a low power engine so the burns wouldn't be so intense. . .

Yep! Same here

The worst part (that I'll never let bug me again) is that infuriatingly flip-flop from one side of the orbit to the other that the P and A do. Sounds like it is just not worth getting it down to that precise of circularity at all.

[jebster]

I don't like perfectly circular orbits, a buffer of around 1km-3km eccentricity prevents the apoapsis and periapsis from shaking all over the place and such