Apollo By the Numbers

[ASCII]

Greetings,
In the Apollo By the numbers documents, they make several references to "Space Fixed Flight Path Angle(deg)", and "Space fixed Heading Angle(E of N)".

I understand that these are describing the craft's current attitude in space, but what is the reference point that is used.

I guess I am unsure what "space fixed" means.

Is there a way to use the HUD in ecliptic mode to get these same values?

 

[Urwumpe]

Greetings,
I understand that these are describing the craft's current attitude in space, but what is the reference point that is used.

Not attitude - velocity vector. FPA is angle of it in the orbit plane, heading is pretty much the orientation of the orbit plane.

space fixed means, it is relative to a celestial reference. The opposite is Earth fixed. Usually it is radius vector for FPA, in this case it is local horizon plane (0° = horizontal). It refers to the space fixed velocity vector, that does not take the rotation of Earths surface in account.

 

[ASCII]

That makes a lot of sense.
Thanks Urwumpe