I've noticed that the JWST hot side sunshield average temperatures were fairly steady during its travel to L2.

Now its orbiting at L2 the hot side sunshield average temperatures are cycling?

I have been entering the daily JWST temps available from the Nasa webb site 'Where is Webb' into an Excel spreadsheet. From the resultant graphs I have guessed the temperature swings on the JWST hot side are likely due to the telescope being re-aligned to lock onto a star. The sunshield angle to the Sun would change slightly, which would alter the temperature on the shield. I hoped for an answer that would end my guessing.

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    $\begingroup$ (unverified speculation, but looks realistic to me) While on way, it had the same angle to the Sun. Now it went to L2 orbit, it was pointed to star, possibly there were also other maneuvers, changing the angle between the sunshield and the direction of the Sun. $\endgroup$
    – peterh
    Feb 15, 2022 at 21:59
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    $\begingroup$ Really need a time plot of one or more individual temperatres to really see what's going on. The hot side temp sensors are likely mounted directly to the solar shield sheeting (speculation). As such, they likely have low thermal capacatance. Thus, they should respond quickly to any changes in orientation relative to the sun as was suggested in above comment. I have no idea if the hot side temps could also be influenced by the controlled cooling (with some periodic heating) going on on the cold side through conduction through the structure. $\endgroup$
    – tckosvic
    Feb 16, 2022 at 19:26
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    $\begingroup$ I sent an email to NASA asking why there were no temperature/time data sets or graphs available as well as descriptions of where the sensors were located prominently displayed. If they can't get that to public display, I asked them to at least put the last day temp as well as the current temp on the display for "where is webb". Let's see if they do anything. $\endgroup$
    – tckosvic
    Feb 18, 2022 at 1:16


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