Wide-field Infrared Survey Explorer science payload overview

The Wide Field Infrared Survey Explorer is a NASA Medium Class Explorer mission to perform and all-survey in four infrared wavelength bands. The science payload is a cryogenically cooled infrared telescope with four 1024² infrared focal plane arrays covering from 2.8 to 26 microns. Advances in focal plane technology and a large aperture allow an all-sky survey to be performed with high sensitivity and resolution. Mercury cadmium telluride (MCT) detectors, cooled to 32 K, are used for the two midwave channels, and Si:As detectors, cooled to < 8.3 K, are used for the two long wavelength channels. Cooling for the payload is provided by a two-stage solid hydrogen cryostat providing temperatures <17K and < 8.3K at the telescope and Si:As focal planes, respectively. The science payload supports operations on orbit for the seven month baseline mission with a goal to support a 13 month extended mission if available. This paper provides a payload overview and discusses instrument requirements and performance.