Wilkinson Microwave Anisotropy Probe
Some of the missions in infrared astronomy that impacted JWST development were Spitzer and the Wilkinson Microwave Anisotropy Probe (WMAP) probe. Spitzer showed the importance of mid-infrared, which is helpful for tasks such as observing dust disks around stars. Also, the WMAP probe showed the universe was "lit up" at redshift 17, further underscoring the importance of the mid-infrared. Both these missions were launched in the early 2000s, in time to influence JWST development.