CIRiS, a CubeSat-compatible, imaging radiometer for earth science and planetary missions

Ball Aerospace has developed CIRiS (Compact Infrared Radiometer in Space), a versatile multispectral, infraredimaging radiometer with on-orbit calibration capability. CIRiS generates images in three spectral bands between 7.5 um and 13.5 um. On-board calibration employs views to two flat-panel, high-emissivity carbon nanotube calibration sources and a third view to deep space. Image processing capabilities of the single electronics board include frame shifting and co-adding, binning and windowing, all with parameters selectable on orbit. An uncooled microbolometer focal plane enables CIRiS to operate without a cryocooler, thereby eliminating the associated power draw, complexity, and mission-life limitation. Total instrument power consumption measured in vacuum is < 10 Watts, including instrument heater power. A modular architecture that permits independent changes to CIRiS subsystems facilitates customization for Earth and planetary science missions. Constellations of 8 to 12 spacecraft carrying CIRiS instruments achieve global coverage from Low Earth Orbit (LEO) with daily revisit times, and varying spatial resolution. Among the potential Earth Science applications are measurements of evapotranspiration, plant health, volcano activity, sea surface and inland water body temperature, and vertical atmospheric profile of temperature and trace gas concentration. Lunar CIRiS, or “L-CIRiS” is a modified implementation for lunar surface mineralogy and thermophysical measurements from a lander or rover on the Moon’s surface. The present CIRiS flight model has completed all testing in preparation for an upcoming demonstration mission in LEO on a 6U CubeSat.