Longitude of ascending node before launch

[Snillum101]

As per title, is there a way to tell your angle from the origin of longitude before launching?

I have the engineer plugin installed but the Longitude of Ascending Node readout does not seem to get accurate until I have at least a little bit of an orbit going.

Thanks.

Edited August 17, 2013 by Snillum101

[Johnno]

You can't have an ascending node before launch since you don't have an orbit/trajectory.

[LameLefty]

You can't have an ascending node before launch since you don't have an orbit/trajectory.

Exactly. All you have is the latitude and longitude of your landing site. If you plan to rendezvous with something once you're back in orbit, what you CAN do is set that vehicle as your target and launch at abut a 45 degree angle directly toward it as it passes overhead. Once you reach a trajectory with a good enough apoapsis (I usually use about 40 - 50 km), plan your apoapsis burn with the maneuver node to raise your periapsis to something similar. By that point you'll also have the ascending and descending nodes of your orbit relative to your target on the map. Circularize your orbit (or at least get the periapsis high enough not to crash), then plan your plane change for the ascending node or descending node as appropriate. If you've "followed" your target during your launch well enough, however, you shouldn't have much of a plane change to make, with luck.

[capi3101]

Uh......50k still leaves you in atmo. If you want a stable orbit, you'll need to go to at least 70k.

In practice I find that waiting until the target is about 450,000 kilometers downrange of KSC prior to launch will give you a rendezvous within an orbit or two. You can watch the nodes as you're making your ascent burn, and adjust your flight trajectory slightly north or south of 090 as necessary to minimize the degree of the nodes. I can usually get within .5 degrees or so this way... it's a tough thing to judge and I've never gotten it exactly correct.

[LameLefty]

Uh......50k still leaves you in atmo. If you want a stable orbit, you'll need to go to at least 70k.

From Kerbin, yes. For some reason I was thinking the original poster was talking about taking off from the Mün or some other airless body like that. I don't know why I thought that. I blame the Kraken.

[Snillum101]

Thanks for the replies.

I'm not having problems with rendezvous manoeuvres and I'm aware that I will not have an ascending node before I launch. I wish to know if there is a way to work out my angle from the origin of Longitude before I launch.

This article here (http://en.wikipedia.org/wiki/Longitude_of_the_ascending_node) kind of explains what I'm on about, I'm just unsure of how to work this out in game.

Edited August 16, 2013 by Snillum101
Clarification

[Rhomphaia]

Cant really think of any way to do it other than launching one test launch at a specific universal time, noting the LAN and then calculating based on Kerbins rotation of 6hours when you need to launch, but it will only really work for identical launches.

a better method would have come in handy though, I just burn from an equatorial orbit, would have been nice to launch directly to inclination.

[Snillum101]

Hmmm... Thanks I'll try that. Though may prove difficult for polar orbits I guess I could launch a satellite and try to put it into a polar orbit with a LAn reading of 0. I could then guestimate based off of that for other launches.

It would be nice to have a plugin that had a map similar to the kethane plugin but with a grid of longitudinal values.