MIMOSA -: A satellite measuring orbital and attitudinal accelerations caused by non-gravitational forces

MIMOSA is a project of a small satellite carrying a highly sensitive electrostatically compensated accelerometer. The device has been already checked on board two spacecraft; to fully use the properties of the accelerometer a special satellite is prepared to gather data on the non-gravitational forces causing the orbital as well as rotational perturbations of close artificial satellites. The projected sensitivity of the device (10(-11) ms(-2)) needs to avoid the parasitic forces (electrical charging, centrifugal force, thermal effects) and to model the measured ones. The data on the atmospheric drag, radiation forces, thermal forces, etc., manifested by the accelerations will be used to define especially the models of the variation and distribution of the atmospheric density distribution of the terrestrial albedo add infrared radiation field. The orbit will have the apogee higher than 800 km to use the direct solar radiation pressure for calibration of the instrument; perigee altitude of 400 km will assure the penetration of the spacecraft into the denser layers of the atmosphere. The rotation of the satellite body shall be slowed down whereas the orientation will be determined with an accuracy better than 1deg. The orbital and rotational mission analysis is based principally on the experience made with the accelerometer onboard of Space Shuttle mission STS-79. The analysis of the results proved excellent technical properties of the accelerometer and the interpretation of the measured data showed agreement of the measured and computed atmospheric density. (C) 1999 COSPAR. Published by Elsevier Science Ltd.