SUMO: Solar Ultraviolet Monitor and Ozone Nanosatellite

Abstract:

SUMO is an innovative proof-of-concept nanosatellite aiming to measure on the same platform the different components of the Earth radiation budget (ERB), the solar energy input and the energy reemitted at the top of the Earth atmosphere, with a particular focus on the far UV (FUV) part of the spectrum and on the ozone layer. The FUV is the only wavelength band with energy absorbed in the high atmosphere (stratosphere), in the ozone (Herzberg continuum, 200–220 nm) and oxygen bands, and its high variability is most probably at the origin of a climate influence (UV affects stratospheric dynamics and temperatures, altering interplanetary waves and weather patterns both poleward and downward to the lower stratosphere and tropopause). A simultaneous observation of incoming FUV and ozone production would bring an invaluable information on this process of solar-climate forcing. Space instruments have already measured the different components of the ERB but this is the first time that all instruments will operate on the same platform. This characteristic by itself guarantees original scientific results. SUMO is a 3.6 kg, 3W, 10x10x30 cm³ nanosatellite ("3U"), with a "1U" payload of <1 kg and 1 W. 5 instruments: an ozone meter, a FUV measure at 215 nm, 2 radiometers (0.2 – 3 & 0.2 – 40 µm) and a bolometer. Orbit is polar, Sun-synchronous, ~600 km, since a further challenge are relations between solar UV variability and stratospheric ozone on Arctic and Antarctic regions. Mission is expected to last 1 to 2 years. SUMO definition has been completed (platform and payload AIT are possible in 24 months). SUMO is proposed for the nanosatellite program of Polytechnic School and CNES (following QB50) for a flight in 2018. Follow-up is 2 fold: on one part more complete measurements using SUMO miniaturized instruments on a larger satellite; on the other part, increase of the coverage in local time and latitude using a constellation of SUMO nanosatellites around the Earth to further geolocalize the Sun influence on our planet. Nanosatellites, with cost and risk limited, are also excellent platforms to evaluate technologies for future missions, e.g. nanotechnology ZnO protection barriers to limit contamination from solar panels in the UV and reduce reflection losses in the visible, or MgZnO solar blind detectors (R&D initiatives proposed to CNES).