Towards in-flight identification of design parameters of a nanosatellite

The paper addresses the problem of defining the domain of applicability for the procedure of identifying the design parameters vector for a nanosatellite in the course of flight development tests. The design parameters vector includes dimensionless inertia factors and design factor of aerodynamic torque. The choice of parameters included in the design parameter vector is driven by their sensitivity to variations in the nanosatellite configuration and mass in the course of the mission. The paper provides results of statistical simulations which make it possible to establish requirements for onboard measuring equipment of a generic nanosatellite, time for accumulating a series of measurement data, as well as for onboard math model of its angular motion dynamics. In order to perform the simulations, a model of design ballistics characteristics of a generic nanosatellite was built. The procedure for identifying the design parameter vector was based on processing the measurement data received from two instruments - a magnetometer and an angular rate sensor. Statistical simulations were run for various phases of a space mission (the phase of the separation from the launch vehicle and the nominal operations phase). The most adequate distribution law was selected for the nanosatellite parameter identification errors (lognormal distribution law). Analytic dependences were obtained for the distribution law parameters depending on the type and properties of the instruments and the time need to accumulate a series of measurement data for a standard 3U-size nanosatellite. These dependencies could be used both at the preliminary stage of nanosatellite design and at the phase of operational mission task generation for an already existing nanosatellite.