Flight Demonstration of a Hyperspectral Infrared 6U CubeSat

Harris Corporation is developing a flight demonstration version of a 6U CubeSat called HyperCube^TM which carries a hyperspectral infrared instrument for remote sensing from low earth orbit. The primary mission of HyperCube is to collect high-resolution mid-wave infrared (MWIR) spectra at the top of Earth’s atmosphere, and to use this data to extract both moisture and temperature profiles within the atmosphere. When moisture profiles at each Earth location are combined, the data produces three-dimensional (3-D) moisture data cubes. Changes in the 3-D moisture field over time can be used to extract 3-D wind information (i.e., wind vectors at multiple vertical locations).

The instrument uses a Fourier transform spectrometer (FTS) interferometer, a cross-track step-stare scanner, a simple passive cooler for detector cooling, an innovative strained-layer superlattice (SLS) infrared focal plane array (FPA), a high-quality onboard calibration target, and onboard signal processing electronics. The instrument operates over a spectral band of 1600-2250 cm^-1 (4.44 to 6.25 microns) at a spectral resolution of 1.0 cm^-1, which provides 650 unique spectral channels. The FPA is cooled to 105K using a two-stage passive cooler, similar in design to the cooler used by the Harris High-resolution Infrared Radiation Sounder (HIRS) infrared sounding instrument. The passive cooler uses a deployable Earth shield to limit the amount of Earth thermal radiation that reaches the cold portions of the cooler. The instrument’s step-stare scanner performs 11 cross-track step-stare observations of Earth, each with a stare time of 0.2 sec. At its nominal altitude of 625km, each detector has a ground footprint at nadir of 5.0 km, and the overall array has a field of view of 30x30km at nadir. The resultant ground swath is 330km wide

This paper describes the design of the 6U flight demonstration satellite, including both the instrument and spacecraft designs. It summarizes the satellite’s expected on-orbit performance capabilities and covers the on-orbit test program, which includes a number of different types of data collects designed to verify the instrument’s ability to perform various types of remote sensing missions including meteorological, climate, and imaging. This paper also describes other design variants that are optimized for other mission applications. A near-space high-altitude flight demonstration is planned for 2018. Launch of the flight demonstration satellite is expected to occur in 2019.