J. Kissel

Checking in on the End station temperatures after the HVAC upgrade. I think I may have found a clue looking into the individual temperature sensors that comprise the average at each end station, which is what's used for the error signal in the FMCS HVAC control servo. Namely, it may be that the first zone is hooked up with a sign flip, or is somehow 180 deg out of phase with the other three zones, which makes the average seem more stable than reality, so the HVAC servo doesn't do anything about it.

In addition to these diurnal oscillations, the overall temperature is trending colder over the past 5-6 days (as reported by the suspensions displacement [first two attachments] and in temperature units, the PCAL temperature sensor), even though the FMCS HVAC error signal is holding steady.

Check out the associated attachments for proof. I've divided up the past 25 days [second two attachments] into several more detailed zooms [the rest of the attachments]: 
    - A pre-upgrade long (~5-6 day) trend
    - A pre-upgrade zoom of one day           -- this shows that all four zones used to be relatively in sync
    - A post upgrade long (~5-6 day) trend    -- this shows that zone A is ~180 out-of-phase with zones B, C, and D

I'll get in touch with Bubba to see if this sign-flipped Zone A is possible, and what we can do about the overall drift.