# Another AGS question 373 timing

#### replicant

##### The Wanderer
So I have been doing a lot of abort, ascent, and rendezvous practice with a totally failed PGNS to great success. Pulling the 3 PGNS breakers and no orbiter HUD cheats. Getting pretty good at it.

In the FP6 manual, for 410 modes +30000 and +40000 it specifically mentions that a 373 maneuver time value must be set. It does not say this is required for a +50000 external delta v mode. This mode is much easier since I can just use maneuver targeting with the RTCC to get circ and TPI delta v’s in all 3 axis’. This is great.

However, the implication I get from the manual is that a 373 time is not required for 410 +50000 because if you are using 400 +10000 steering the logic tells it to simply hold the right orientation infinitely awaiting your command to burn off the number in DEDA readout 500. This implication is furthered in the note that says the AGS will do orbital rate steering by tricking it. Place +05000 in 450 for instance, and it will maintain itself perpendicular to (x) posigrade infinitely as if awaiting your burn off command.

This doesn’t seem to be the case. To get the right orientation even in 410 +50000 mode I need to set the desired 373 time of the maneuver. Not a huge deal, just kind of a gee whiz thing. Is it a difference in AGS software at different times? I have seen this with 14 15 and 16.

As a side note, the book also cautions rcs 410 +50000 burns. It says for very small burns or for trimming residuals, beware that the auto steering might get confused and aggressively start to infinitely spin trying to orient itself for small residual trim. It says do small delta v’s or residuals in attitude hold mode.

I can confirm that in this case, it will do that crazy spin like the book says.

Thanks as always.

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#### rcflyinghokie

##### LM Junky
The 373 address is TIG of the next maneuver, so it is needed for your 410+2/3/4 calculations. Those calculations in turn are what would be used to compute dvs needed and stored in 450/51/52 for 410+5.

410+5 by itself can be used but 450/51/52 all are loaded manually without 410+2/3/4 being used to store those addresses.
On the attitude excursions, auto maneuvers in AGS are generally not used because of this behavior, AGS pulse is used to null the error needles in that case, and those needles will always be aiming +X.

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