DG to ISS

[startrekmaniac]

Are there any tutriols to get to the ISS with the DG?

 

[MJR]

There should be one at orbithangar.

 

[n0mad23]

Ask and ye shall receive:

[ame="http://www.orbithangar.com/searchid.php?ID=3074"]Tutorial: DG to ISS[/ame]

 

[startrekmaniac]

Okay, I can get my RInc to about 0.75. Is that close enough to start SYNCRONIZING my orbit? Or does it need to be 0.01?

 

[tomek]

I think there's a tutorial right in the manual actually...

Relative inclination means two things. First, if it's too high, you'll only be able to get anywhere close to your target at the "nodes", where your orbits actually intersect, because after that orbits will start diverging. For .75 degrees the farthest you'll get from your target's orbit is about 200km, so it's not too bad. Transponders in Orbiter start working at about 500km, so at 200km you'll have your target "in sight" (on the HUD) and could go from there; however, you really should aim for an orbit that'll get you within at least 100km, or approach will get funky because you'll constantly get "pulled" sideways due to orbit differences - which will translate into wasted fuel (but it doesn't matter nearly as much on DG as it does on Atlantis or fully-loaded Shuttle-A. You may also try using Rendezvous MFD to make things simpler and more efficient (but I never tried it, and I think it actually also assumes that your orbits are already synchronized).

Second, relative inclination is basically sideways velocity you'll have with respect to your target, once you get near it. The more the inclination, the larger the burn you'll need to stop by ISS. 0.75 would mean something like extra 200m/s sideways, which is doable with DG.

So yes, you can start synchronizing your orbit at .75 degrees. After that, if your closest approach will be few hundred kilometers, you have two options. If you start flying towards your target right away, it'll mean you're increasing your RInc, only to have to decrease it again once you're near the target (that's faster but more expensive in fuel - but in Orbiter fuel is free and DG has lots of it). Second option is to just use your HUD to nullify your Orbital velocity with respect to ISS - and after that coast for a quarter of an orbit (until your positions converge), then kill the relative velocity (which will essentially be orbit alignment burn), and from there proceed with the final approach.

 

[dutchpirate]

Are you using the stock DG, or the DGIV?

 

[MJR]

Most likely the stock.

 

[pete.dakota]

Okay, I can get my RInc to about 0.75. Is that close enough to start SYNCRONIZING my orbit? Or does it need to be 0.01?

To get less than 1 RInc after launch is acceptable. Now use AlignplanesMFD to get it down to zero BEFORE your rendevouz. It's always best to do as much as you can before you reach the ISS.

 

[dutchpirate]

I'm with Pete, getting your parameters as tight as possible before rv helps a lot! Remember, you can use your RCS in linear mode for super-fine burns.