The Wide-field Infrared Survey Explorer (WISE), a NASA infrared-wavelength astronomical space telescope, was active from December 2009 to February 2011. It was launched on December 14, 2009, and decommissioned/hibernated on February 17, 2011 when its transmitter was turned off. It performed an all-sky astronomical survey with images in 3.4, 4.6, 12 and 22 μm wavelength range bands, over 10 months using a 40 cm (16 in) diameter infrared telescope in Earth-orbit. The initial mission length was limited by its hydrogen coolant, but a secondary post-cryogenic mission continued four more months with two of the four detectors remaining operational.

In September 2013, the spacecraft was reactivated, renamed NEOWISE and assigned a new mission: to assist NASA's efforts to identify and characterize the population of near-Earth objects. NEOWISE is also characterizing more distant populations of asteroids and comets to provide information about their sizes and compositions.