Flight Question Launch heading to ISS rendezvous

[VincentMcConnell]

What is a preferable launch heading to launch into the orbit of the International Space Station and when (on my MFD's orbit track view) should I actually lift off? I'm using the Delta-Glider IV.
My friend and I were previously using a launch heading of 42 degrees but I'm not sure whether to launch when the ISS orbit track is going south or north of my current location.

Is 42 degrees a good launch heading? If not, what is a better heading and when should I click the button to launch?

If you could please supply a screenshot of the Map MFD's orbit plane view at the time when I should lift off, that would be excellent. Thanks in advance, everyone.

 

[malisle]

I suggest you take a look at [ame="http://www.orbithangar.com/searchid.php?ID=2802"]Launch MFD[/ame]. It gives you all the information you need, but you can also do it manually. All you have to know is what is the inclination of your launch site and the inclination of your desired orbit (both can be seen in Orbit MFD). For example, if you launch from Cape Canaveral (28.5°), and are heading to ISS (51.6°) desired launch azimuth is ~45° or ~135°, depending on the orbital path.

Source: orbiterwiki.

How soon should you launch? X minutes before orbital path of ISS crosses your launch site on the MapMFD, where X is the time needed for your spacecraft to reach half of the orbital velocity. Usually a few minutes.

 

[PhantomCruiser]

If the ISS is moving from SW to NE, then yes 42 (ish) is a decent heading. It won't be perfect through the entire climb to orbit though. Launch MFD can help, or if you want to stay with the stock MFDs, then watch the AlignPlanesMFD during your launch and nudge your heading to minimize RinC.

"Click the button to launch" tells me you are using the DGIV autopilot program? If this is the case, Tex has a pretty good video here, http://www.orbiter-forum.com/showthread.php?t=2055

 

[VincentMcConnell]

Thanks everyone. I started launching into a 43 degree heading and usually have less than a degree of relative inclination to null between DGIV and ISS by the time I reach orbit. Just did two successful rendezvous missions to the ISS in a row.

 

[PhantomCruiser]

Excellent! Welcome to LEO. Booze is in the sqeeze bottle on the left there...

 

[N_Molson]

With practice, you can lower the RInc to 0.1° or less. Then you are pretty close of the real thing. But to get that, you need to wait that the ISS track passes perfectly above the Cape. Then the concept of launch windows.

 

[Interceptor]

Hi Molson,I have no problems getting the rinc to 0,but how do you keep it from climbing up again?just some advice please.Thanks

 

[Urwumpe]

Hi Molson,I have no problems getting the rinc to 0,but how do you keep it from climbing up again?just some advice please.Thanks

You simply have to keep all acceleration in the orbital plane once it is zero. The Surface HUD of Orbiter displays surface relative coordinates, which rotates with Earth, use Orbit HUD then.

 

[VincentMcConnell]

I didn't want to make another thread for this because it's somewhat on the same topic, but I was a little curious about the inclination of the Space Station in orbiter. In Orbiter, it's inclined at over 70 degrees. But Wikipedia says the real ISS has an orbital inclination of ~51?

 

[Loru]

Well - you have to check in what frame of reference you're looking.

In ecliptic plane it can be ~70 degrees however in equatorial it will be in 51.