sorindafabico
New member
This little tutorial is about finding good launch windows for LEO targets (such the ISS) when you want to use a launcher with autopilot (DGIV, Shuttle Fleet, etc.) and getting almost zero RInc. Sorry for possible "bad english" moments 
Maybe there's a formula to calculate this, the following content is totally empirical.
It was a matter of luck for me to get a very low RInc with some excellent launchers like Thornton's Soyuz or Shuttle Fleet. Then I discovered that every time you do an autolaunch of a determined veichle from a determined site to a determined inclination, the difference of the equatorial LAN of launch time and equatorial LAN of MECO is roughly the same.
With that, if you know the "delta-LAN" of your ship from your launch site to a stable orbit with 51.6 degrees of inclination, you are able to know when launch to ISS with almost zero RInc.
You can do that by following these steps:
1. Choose a vessel with automatic launch (works for manual too, but this is not so useful when you can do corrections manually).
2. Choose your target in LEO (ISS, Hubble, etc.) and your launch site.
3. Do a "test launch" to find the "delta-LAN": you must launch to the chosen orbital inclination. Take note of equatorial LAN at the moment of launch (or T-xxx seconds if you are programming your launch in a Soyuz FG/U addon style).
4. Wait MECO and take note of equatorial LAN again. The difference between the values is your "delta-LAN".
5. You are ready for the real launch. When your target's orbit is aligned with your launch site (you can estimate when this happens with MapMFD or LaunchMFD), look at eq.LAN in OrbitMFD. Your launch time/"begin countdown time" is when the difference of target's LAN and your LAN is equal to "delta-LAN". Example: your "delta-LAN" is 60 degrees and target's LAN is 160 degrees. You must launch/start countdown when your LAN is 100 degrees.
Here are a few examples of delta-LAN to the ISS (Inc = 51.6). I found that delta-LAN is roughly the same for each latitude, but the differences between the numbers of each ship (specially DGIV) are big enough to spend a lot of fuel aligning with the ISS.
Delta-LAN to ISS (51.6):
From KSC:
- DeltagliderIV: delta-LAN 65.93 (Engine start) | Az. 42
- Shuttle Fleet: delta-LAN 65.23 (T-10) | Az. 40.8*
- Falcon 9 + Dragon: delta-LAN 65.57 (T-0) | Inc 51.6
From Baikonur:
- Soyuz: delta-LAN 37.30 (T-120) - 36.79 (T-0) | Inc 51.6
* Shuttle Fleet's autopilot sends you to another inclination with the 42º azimuth.
Here's an example. I launched the Falcon 9 to 51.6 when my eq. LAN was 100.83 degrees. Almost all RInc is due to difference in inclination (I don't know why):
*This example is BAD, I already got RInc < 0.05
Maybe there's a formula to calculate this, the following content is totally empirical.
It was a matter of luck for me to get a very low RInc with some excellent launchers like Thornton's Soyuz or Shuttle Fleet. Then I discovered that every time you do an autolaunch of a determined veichle from a determined site to a determined inclination, the difference of the equatorial LAN of launch time and equatorial LAN of MECO is roughly the same.
With that, if you know the "delta-LAN" of your ship from your launch site to a stable orbit with 51.6 degrees of inclination, you are able to know when launch to ISS with almost zero RInc.
You can do that by following these steps:
1. Choose a vessel with automatic launch (works for manual too, but this is not so useful when you can do corrections manually).
2. Choose your target in LEO (ISS, Hubble, etc.) and your launch site.
3. Do a "test launch" to find the "delta-LAN": you must launch to the chosen orbital inclination. Take note of equatorial LAN at the moment of launch (or T-xxx seconds if you are programming your launch in a Soyuz FG/U addon style).
4. Wait MECO and take note of equatorial LAN again. The difference between the values is your "delta-LAN".
5. You are ready for the real launch. When your target's orbit is aligned with your launch site (you can estimate when this happens with MapMFD or LaunchMFD), look at eq.LAN in OrbitMFD. Your launch time/"begin countdown time" is when the difference of target's LAN and your LAN is equal to "delta-LAN". Example: your "delta-LAN" is 60 degrees and target's LAN is 160 degrees. You must launch/start countdown when your LAN is 100 degrees.
Here are a few examples of delta-LAN to the ISS (Inc = 51.6). I found that delta-LAN is roughly the same for each latitude, but the differences between the numbers of each ship (specially DGIV) are big enough to spend a lot of fuel aligning with the ISS.
Delta-LAN to ISS (51.6):
From KSC:
- DeltagliderIV: delta-LAN 65.93 (Engine start) | Az. 42
- Shuttle Fleet: delta-LAN 65.23 (T-10) | Az. 40.8*
- Falcon 9 + Dragon: delta-LAN 65.57 (T-0) | Inc 51.6
From Baikonur:
- Soyuz: delta-LAN 37.30 (T-120) - 36.79 (T-0) | Inc 51.6
* Shuttle Fleet's autopilot sends you to another inclination with the 42º azimuth.
Here's an example. I launched the Falcon 9 to 51.6 when my eq. LAN was 100.83 degrees. Almost all RInc is due to difference in inclination (I don't know why):
*This example is BAD, I already got RInc < 0.05
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