A novel CubeSat payload for airglow measurements in the mesosphere and lower thermosphere

The Institute for Atmospheric and Environmental Research at the University of Wuppertal and the Institute of Energy and Climate Research Stratosphere (IEK-7) at the Research Center Juelich developed a novel CubeSat payload for atmospheric research. The payload consists of a small spectrometer for the observation of airglow at 762 nm. The line intensities of the oxygen A-band are used to derive temperatures in the mesosphere and lower thermosphere (MLT) region. The temperature data will be used to analyze dynamical wave structures in the atmosphere which have become increasingly important for the modeling of the climate system. Integrated in a 6U CubeSat, the instrument needs a highly accurate attitude determination and control system (ADCS) for limb sounding of the atmosphere. The agility of a CubeSat shall be used to sweep the line-of-sight through specific regions of interest to derive a three-dimensional image of an atmospheric volume using tomographic reconstruction techniques. The spectrometer technology chosen to measure the ro-vibrational structure of the O2 atmospheric band at 762 nm is a Spatial Heterodyne Interferometer (SHI) originally proposed by Pierre Connes in 1958. The throughput of an SHI is orders of magnitude larger than of a conventional grating spectrometer of the same size. It can be designed to deliver extraordinary spectral resolution to resolve individual emission lines. The utilization of a two-dimensional imaging detector allows for recording interferograms at adjacent locations simultaneously. Since an SHI has no moving parts, it can be built as a monolithic block which makes it very attractive for remote sensing, especially from space.