Making a Kolnya orbit

[xcorps]

So I've been fighting a Pre Mun Kolyna satellite mission for a while now. I've almost managed it twice, but I just haven't had the tech to overcome the 30 part limit AND the weight limit. (I could do it without both limits, grr)

So I need to optimize the way to make this orbit happen, I'm thinking specifically on the normal burn to match planes. With a required AP of 3.096mm and a PE of 70km, would it pay me in terms of Dv to make a big orbit of say 3 million meters circular, then do the inclination match and then change the PE to meet the requirements? I can't make maneuver nodes yet, so I have to do this "seat of the pants", and I'm NOT even considering trying to combine an AP and NML burn to match planes and AP at the same time, I want to do it in steps.

Regards.

EDIT:

I'm making the NML burn by making Kerbin the center of focus and lining up the AN and DN of the desired orbit, then burning when my ship crosses that plane. That the best way to do it?

Edited January 16, 2015 by xcorps

[Kryxal]

You'll be far better off if you launch into something at least close to the plane of the final orbit, good launch points will happen twice per six hours.

Beyond that, it's probably not worth making the orbit circular for the plane change, but if it's a big change it may be worth pushing the periapsis out at least some of the way.

[Dr. Death]

how about making individual parts and docking them on space?

[Wanderfound]

This is for FAR, and may use some tech you don't yet have, but the basic principles illustrated should apply just as well in stock without too much tech.

Annotated demonstration at http://s1378.photobucket.com/user/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/Satshot/story

TLDR version: launch directly into the required plane on a big SRB, top the SRB with an ultralight satellite that can draw a few thousand ÃŽâ€V and ridiculous TWR from a tiny engine and fuel tank.

[tsotha]

I'm making the NML burn by making Kerbin the center of focus and lining up the AN and DN of the desired orbit, then burning when my ship crosses that plane. That the best way to do it?

Do that but from the pad.

You should be able to do this well within the 30 part and 18T limits, though your ship may not be as cheap as possible because cheap SRBs drive up the weight.

The way I would do the flight is launch into the plane and direction of the final orbit, circularize, correct the plane (should be off by 0.8 or so at the most), burn opposite Ap until Ap is correct, then do the same for Pe. Collect cash and prizes.

You can do the plane correction in the final orbit, but for highly elliptical orbits that usually costs you fuel instead of saving it.

[vexx32]

Unless the inclination is more than 15 degrees off of equatorial, you can do the plane change as you are doing it. Any higher than that, and you probably want to consider trying to launch directly into the right plane.

[xcorps]

Do that but from the pad.

You should be able to do this well within the 30 part and 18T limits, though your ship may not be as cheap as possible because cheap SRBs drive up the weight.

The way I would do the flight is launch into the plane and direction of the final orbit, circularize, correct the plane (should be off by 0.8 or so at the most), burn opposite Ap until Ap is correct, then do the same for Pe. Collect cash and prizes.

You can do the plane correction in the final orbit, but for highly elliptical orbits that usually costs you fuel instead of saving it.

Got it. I got the inclination pretty close by eyeballing it like that and had to do just a few hundred dv worth of inclination change afterwards. I had almost 2000 dv left when I made the orbit. Dv I had burned to no avail on the last 5 attempts.

Thanks everyone!

[Srpadget]

Molniya orbits are 63.4 degrees inclination. You can save a LOT of dV if you launch into (roughly) the correct plane. Your tactic of lining up the AN/DN markers on the target orbit is a good start--do that prior to launch, so that you can time your launch for just a couple minutes prior to crossing the target orbit plane. Manually set your navball to "orbit" mode before you launch, rather than the default "surface" mode. Launch as normal, but rather than doing your gravity turn to the east (90 degrees, for an initial orbit of 0 degrees inclination), do your gravity turn directly onto ~27 degrees or ~153 degrees. It won't be perfect, but that intimidating and dV-eating plane change will be a piddly low-single-digit handful of degrees.

Tip: trying to steer at an odd angle like 153 degrees is nigh-impossible to do well (manual piloting in stock anyway) if your craft's 'natural' axis is pointed North-South or East-West. You have to control two axes at once while eyeballing single-degree precision on a navball that's barely suited to 10-degree increments. Much better to launch, roll (while still vertical) so that your ship's natural axis is pointed to 27 or 153 degrees using the digital display at the bottom of the navball, and then your gravity turn is a pure pitch maneuver, while steering to stay on heading is pure yaw (and maintaining attitude so that those two activities stay completely separate is roll's job). And staying on heading is made vastly easier by using that accurate-to-one-degree digital display.

I love molniya and tundra contracts. Once you get the hang of them, they're dirt-simple and pay outlandishly well for the time and trouble invested.