Preliminary review of microgravity environment in Russian segment of ISS

The paper presents the first results of residual accelerations determination in ISS Russian Segment in spring and summer 2001. A quasi-steady acceleration component was determined using telemetry information about the station attitude motion. The information contains values of the station angular rates and the quaternion of the station attitude with respect to an inertial coordinate system at some instants. Basing on the information, we reconstruct the station motion and calculate the acceleration at any given point on its board as a function of time. As a rule telemetry information we have allowed us to calculate acceleration during orbital periods. The main part of this approach is the reconstruction of the station attitude motion. We have a few various techniques for solving this problem that differ by used mathematical models of the station attitude motion and types of processed telemetry information. A vibrational acceleration component was measured by several three-axis accelerometers IMU-128. They measure accelerations with magnitude more then 0.001 m/s$^2$ in the frequency range up to 20 Hz. Although, the accelerometers IMU-128 are not very sensitive, they are able to measure typical accelerations caused by operation of onboard equipment.