Flight Question AMSO + Aerobrake MFD, calculations inverted?

[andqui]

Hello-

I am using Orbiter 2016 with AMSO and Aerobrake MFD. I have an Apollo mission returning on a perfect 6.5 degree reentry angle and I'm trying to use Aerobrake MFD to better hit the landing target.

For re-entry, I point retrograde with heads down, so that I pitch "down" (away from earth) to a positive AOA to generate lift. That is working OK- the more I pitch that way, towards positive AOA and away from the ground, I generate more lift and my vertical speed trends positive. The same is true with the opposite, more negative AOA and my sink rate increases and G loads build up.

The prediction screen on AerobrakeMFD seems to have this backwards, pitching with more lift/positive AOA causes the trajectory line to shorten and max G to increase, wheras less lift/negative AOA makes a prediction that corresponds to more lift. Something is inverted, either the input aerbrake MFD uses, or AMSO using some atypical coordinate system that confuses aerobrake MFD.

Does anyone know what might be wrong, or how to fix it?

Thanks

 

[Marijn]

What do you mean with pointing retrograde for reentry? That sounds odd to me.

 

[andqui]

By retrograde I mean you point the heat shield forwards. Prograde is in the direction of the docking port.

 

[Marijn]

Ah, ok. That sounds right. But I am unsure whether Aerobrake MFD can be used for that.

 

[andqui]

Is it only for spaceplanes? Maybe that's why it's inverted for a retrograde capsule?

 

[NukeET]

The prediction screen on AerobrakeMFD seems to have this backwards, pitching with more lift/positive AOA causes the trajectory line to shorten and max G to increase, wheras less lift/negative AOA makes a prediction that corresponds to more lift. Something is inverted, either the input aerbrake MFD uses, or AMSO using some atypical coordinate system that confuses aerobrake MFD.

Does anyone know what might be wrong, or how to fix it?

Has anyone replicated this with Aerobrake + NAASP? Or any other spacecraft that mimics a meteor?

 

[andqui]

Has anyone replicated this with Aerobrake + NAASP? Or any other spacecraft that mimics a meteor?

I can try to download orbiter 2010 and NAASP and test it. It would be a shame if aerobrake only works for prograde spaceplanes, it would make it much easier to manage G's and hit the correct target (both in range and azimuth) when coming in with an apollo or soyuz capsule.

I posted some screenshots and more info in the aerobrake mod thread:

https://www.orbiter-forum.com/showthread.php?p=606438&posted=1#post606438