It is my understanding this is supposed to be a Question and Answer site, but a user who seems to want it to be a forum, so as they can't say "hey guys, look what I found" they persist in writing contrived questions to expose nuggets of information.
That they say "I try to write these carefully" is a clue that this behaviour is deliberate:
This question while apparently being asked about the star trackers, with a strangely$^1$ tacked on question about an equipment bay is actually asking about what isn't there. The answer to the direct question asked (They're star trackers, and they're not pointing in the same direction) isn't acceptable.
Instead this user is fishing for a discussion on the Fine Guidance Sensors - one of which has been removed from the bay in the photograph accompanying the question - which are a bit like a star tracker, but use the Hubble's primary optics. Interestingly, while two are needed for the high accuracy pointing, the third can be used as a science instrument.
This question while ostensibly asking about why you don't see your arm while taking a selfie, (while including a selfie of the arm in the question) appears to be fishing for information about other cameras on the platform, or the stitching of the images.
This question seems to have been created to discuss a youtube video, but was originally worded in terms of disbelieving vidicon signals were recorded to tape in space in the early 60s - the user later denied this was the intent, but had previously rolled-back my good-faith edit to his question on the grounds that showing the location of the recorders used for video undermined the question. (and this user is not averse to adding many pictures to his questions, I assume to make them visually interesting, because they're often barely relevant) Of course, the answer to that question is "they weren't" because while the signal from a vidicon tube was recorded on tape, it was nothing like what we call a video recording now (or even compared to contemporary video recorders)
1: because an experienced user knows it's just meant to be one question per question)