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Hubble needed to hide mirror because it is passing from sunlight into shadow every 47 minutes and mirror has to be protected from thermal stress. Also Earth emits some light even on night side that would interfere with observations.

JWST's mirror is always in shadow and stray light from sides will not be a problem at L2.

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That makes a lot of sense, thanks.

If you're interested in a more indepth view of how it's supposed to work, Real Engineering did a video about it recently.

No idea if what they're saying is true however, I've no knowledge about the domain.

https://youtu.be/aICaAEXDJQQ

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