SERB, an innovative proof-of-concept nanosatellite mission dedicated to the measurement of the Earth radiation imbalance

The Solar irradiance and Earth Radiation Budget (SERB) is a future innovative proof-of-concept nano-satellite. The main objective of SERB is to measure the true Earth Radiation Imbalance, which is a crucial quantity for testing climate models and for predicting the future course of global warming. All estimates (ocean heat content and top of atmosphere) show that over the past decade the Earth radiation imbalance ranges between +0.5 to +1 W.m^-2. Up to now, the Earth radiation imbalance has not been measured directly. The only way to measure the imbalance with sufficient accuracy is to measure both the incoming solar radiations (total solar irradiance) and the outgoing terrestrial radiations (top of atmosphere outgoing longwave radiations and shortwave radiations) onboard the same satellite, and ideally, with the same instrument. This paper is intended to present the configuration of the SERB nanosatellite, which is a 3-Unit CubeSat (10 x30 x 50 cm in a deployed configuration). The objective is to demonstrate the ability to build a low-cost satellite with a high accuracy measurement in order to have constant flow of data from space. Moreover, instrumental payloads (solar radiometer and Earth radiometers) can acquire the technical maturity for the future large missions (constellation that insure global measurement cover) by flying in a CubeSat.