Design temp for the MIRI detectors is 6.7K. The front end electronics produce some heat, and are in a metal box sealed against light leaks, so they'll need some

Design temp for the MIRI detectors is 6.7K. The front end electronics produce some heat, and are in a metal box sealed against light leaks, so they'll need some active cooling. Skimming this paper https://www.stsci.edu/files/live/sites/www/files/home/jwst/documentation/technical-documents/_documents/paper2.pdf https://www.stsci.edu/files/live/sites/www/files/home/jwst/d... it looks like they expect 10.46mW optical module heat, and they've given themselves 36mW of headroom "for conductive and radiative loads." (Heat conducted from the structure, and radiant heat from the the comparatively warm primary mirror?)