We have been developing sensitive long-wave infrared (LWIR) cutoff detector arrays for use in the proposed Near-Earth Object Camera (NEOCam) Discovery mission [ (mercury cadmium telluride) is a II to VI ternary compound, whose molar cadmium fraction can be varied to tune to the desired cutoff wavelength].1 NEOCam is a survey mission designed to find, track, and characterize asteroids and comets in our solar system, including most of those greater than 140 m in size that travel close to Earth, the near-Earth objects (NEOs). There is particular emphasis on finding those NEOs with the potential of impacting the Earth. NEOCam will operate at two wavelength ranges 4 to and 6 to . The shorter wavelength HgCdTe detector arrays have already been designed for the James Webb Space Telescope (JWST),2 and our group at the University of Rochester (UR), in collaboration with NASA Jet Propulsion Laboratory, has been working with Teledyne Imaging Sensors (TIS) to produce the detector arrays that will cover the longer wavelength range. Laboratory testing of several arrays grown on an CdZnTe substrate, and hybridized to an H1RG multiplexer, demonstrated that the resulting detector arrays met all NEOCam requirements (see Table 1) for dark current, quantum efficiency, well depth, and noise.3 Short-wave infrared (SWIR) and mid-wave infrared (MWIR) HgCdTe detector arrays utilizing the same multiplexer, or the same family of multiplexers in a larger format, have been or will be employed in other space missions, including the Orbiting Carbon Observatory 2, the Wide-field Infrared Survey Explorer (WISE), the Hubble Space Telescope’s (HST) Wide Field Camera 3, Euclid, and JWST.2,4,5–7 Detector arrays flown in space must be robust against cosmic ray (CR) hits; therefore, we subjected the arrays from 12 to 63 MeV protons to determine the magnitude of the responses.