#JWST needs to be very cold to avoid emitting light at the same IR wavelengths as its faint celestial targets.
It does so by hiding behind a huge sunshield, cooling radiatively into the blackness of space.
Although vindicated by the observatory's astonishing performance today, it was a struggle to convince the community of this approach.
This article by Harley Thronson tells of the key role played by Tim Hawarden & other UK astronomers, & the POIROT & Edison concepts.