Wide-field Infrared Survey Explorer cryogenic support system lessons learned

The Wide-Field Infrared Survey Explorer (WISE) is a JPL-managed MIDEX mission to perform an infrared all-sky survey. The WISE instrument, developed by the Space Dynamics Laboratory (SDL), is a 40-cm cryogenically-cooled telescope which includes a cryogenic scan mirror and four infrared focal planes (2-HgCdTe, 2-Si:As). Cooling the instrument to the desired temperatures is accomplished by a two-stage, solid hydrogen cryostat, provided by Lockheed Martin Advanced Technology Center (LMATC). Required temperatures for the instrument optics and Si:As focal planes are <13 K and <7.6 K respectively. To reduce heat loads, the vacuum shell is isolated from the spacecraft bus via composite struts and radiatively cooled to <200 K. The telescope aperture is protected from on-orbit environmental loads via a two-stage radiatively cooled aperture shade. WISE was successfully launched into a 530 km, polar orbit on December 14, 2009, beginning a 10-month mission to survey the entire sky in the infrared.