Calculating Launch Times

[James.Denholm]

Hey all, I was just wondering if there was a mathmatical formula that I could use to work out possible launch times to Space Stations, when the planes are allredy alligned (or pretty close).

 

[C3PO]

You can get close, if you know you'r ascent profile.

Check how long it takes to get to ½ of the final orbital speed. Then you can use AlignePlanesMFD to see how far away you are from alignment. When Time To Node (Tn) matches the time to reach ½Orbital speed, it's time for liftoff.

 

[James.Denholm]

Cheers, but assuming I know my acent profile, is there anyway to figure out these things in a more mathmatic, acurate way? I ask because I'm planning on building a space station soon (using SSBB, of course) and want to figure out a time-table sort of thing, which I assume is how they do it in real life.

 

[agentgonzo]

If the station's orbit doesn't precess then your launch windows will be separated by the sidereal time of the Earth (23h56m4.090530833s). You have two launch windows per day.

 

[James.Denholm]

Sorry agentgonzo, but what does "precess" mean? Thanks, by the way.

 

[Poscik]

You don't have to count launch window manually because LaunchMFD do it for you

 

[C3PO]

Cheers, but assuming I know my acent profile, is there anyway to figure out these things in a more mathmatic, acurate way? I ask because I'm planning on building a space station soon (using SSBB, of course) and want to figure out a time-table sort of thing, which I assume is how they do it in real life.

I'm not sure what you want exactly.
AlingPlanesMFD lists both Rinc and Rate-of-change, and it's quite easy to calculate the next plane alignment.
If you plan to use SSU, you can do a test flight to determine the time to ½Orbital speed. It will not change that much if you launch to the same inclination every time.

I know division and subtraction isn't very fancy, but I don't think you'll find anything that's more mathematical.

If you turn on nonspherical gravity, the LAN of orbits will change. This is called precession.

 

[agentgonzo]

Sorry agentgonzo, but what does "precess" mean? Thanks, by the way.

http://en.wikipedia.org/wiki/Precession

 

[joeybigO]

James, I used to have a mathmatical calculation, however I lent the book to Rich Wall (hotdog) I just re-ordered the book and it should be here shortly (within 1-3 days) and I can get you the accurate mathmatical calculation to determine the launch windows.

There used to be a dirty way, I used to have it on my PC, but that PC now is in Arizona and i'm in San Antonio. :-(

 

[James.Denholm]

Oh, I get it now. Thanks guys!