Launching into precise inclinations

[NFunky]

Hey guys, you're always so helpful, so I thought I'd see if you have any tips on this one. I've been flying a shuttle thingy with four asparagus staged tanks feeding the shuttle's one Mainsail. With the help of four of the S1 SRBs, it can get into orbit (3.7x Kerbin) with a fairly sizeable amount of monoprop, two O-10s and RCS. It has a bunch of cargo space, but with a heavy payload of life support containers, it loses a lot of dV in the final monoprop stage. Empty, it has about 300 dV, but with payload it gets only like 90.

Anyway, I'm very interested in conserving dV once on orbit, and of course, I've discovered that inclination changes can eat up over half my monoprop for just a degree or two. There's a station on a 22 degree 110 km orbit, so if I can launch into a close enough inclination, I use hardly any dV to rendezvous. With my lack of docking skills too, I need all the fuel I can get at that point. I find launching into a precise enough inclination pretty difficult though. Ideally, I'd like to get it down to less than 0.8 degrees relative. Any final corrctions at this point will only use a quarter or less of my monoprop.

So I'm just looking for general tips on launching into very precise inclinations. For instance, how long before KSC crosses the node should I launch? And I seem to be having the most trouble in the very last phase of the ascent. Even the slightest deviation will rapidly change the relative inclination, so I'm constantly trying to correct and overcorrecting. I'm assuming I should be doing most of the plane change during the first few minutes of flight right?

Thanks

[NathanKell]

Here's a page that describes what you're asking for. Just change the rotational component to be what you see, landed, in "Orbit" mode on the navball, that's your initial rotational velocity.

http://www.orbiterwiki.org/wiki/Launch_Azimuth

[FancyMouse]

>how long before KSC crosses the node should I launch?

This depends on your launch profile. Specifically how you build up your horizontal speed. The above link tells you general case, but for this question, you need to test yourself (and probably spare some extra dV for post launch adjustment). Btw I'm happy to launch into something within 5 degree error and adjust instead of relaunching at a better time.

[Targa]

The simple solution is to use MechJeb and type in the degree of inclination you want. Don't know if you'd rather do it yourself or not. I look at MechJeb more like an on-board computer which any decent rocketship should have anyway. Besides which, after you've done maneuvers a few dozen (or hundreds) of times, it can get a bit tedious.

[NFunky]

Thanks guys.

I'm mainly trying to get under 1 degree during launch because my shuttle's only has about 100-150 dV. Anything more than a degree and I tend to run out of fuel during docking. I don't really have enough lifting power to add much more monoprop.

I've learned that if I get within a few degrees during initial ascent, I can just point prograde until the last few seconds of burn, then just turn towards target an I'll get pretty close. The other ytick I've learned is doing my final insertion buen as close to the node as possible and correct as much as possible during that burn. If I don't have time to set up a maneuver node, I just try to aim between prograde and normal/ antinormal.

Any other tips and tricks would be greatly appreciated.

[Nich]

Not sure why you are using a final monoprop stage. Is it more dense and you have space restrictions? Get rid of or drastically reduce the final monoprop stage those things have terrible ISP. Even if you are using supper gimped momentum wheels you should be able to get within 50m with a momentum wheel and main LFO engine (ant). I routienly dock 5t satalites with just the .3 tourqe of the probe core and the main engine. In addition 75 isp on the circulation stage can mean the difference between 75x75 LKO or orbiting the Mun