THERMAL VACUUM TESTING AND CHARACTERISTICS OF THE POLYITAN-НР-30 2U CUBESAT UNIVERSITY NANOSATELLITE

The paper presents the results of thermal vacuum tests of the PolyITAN-HP-30 university nanosatellite of the 2U CubeSat format un- der the conditions of ground-based physical modeling of the main operating factors of outer space, which satisfy the sun-synchronous orbit with an altitude of up to 550 km. The tests were conducted following the requirements of the European Community for Space Standardization (ECSS) and are standardized and regulated by documents. The performed thermal vacuum tests are a mandatory and important stage for the development of reliable space equipment, which extends its operational lifespan. The equipment for thermal vacuum tests available at National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute» (Igor Sikorsky Kyiv Polytechnic Institute) provides modeling of “cold” and “black” space, fosters the implementation of scientific and technical approaches and solutions for the development and implementation of new space technologies and methods for conducting thermal vacuum research/tests, and helps to develop measurement tools and systems to obtain reliable technical characteristics of working components and assemblies of the spacecraft. The article describes the structure and construction of the university nanosatellite (NS). The main characteristics of the electronic components, the payload of the NS in the form of a thermal stabilization system from mini-heat pipes, are presented. The authors emphasize that the electronic platforms include mass-produced elements that are usually not designed to operate in the harsh conditions of outer space and, therefore, require careful verification of their functioning in these conditions. Besides, before launching into space, they must always be subjected to thermal vacuum tests. The article specifies the main requirements for conducting ground-based research and testing of a university NS. References are given to the main characteristics of the bench equipment used in the work, as well as the quantitative characteristics of the NS. The test results are presented in the form of graphical dependences of the temperature changes of the NS’s elements on time. The analysis of the data obtained from thermal balance tests in the cycling mode in the temperature range from –20 °С to +50 °С was carried out. The flight sample of the NS was degassed at ambient temperatures in the experimental chamber from 50 °С to 55 °С and a vacuum of 1.0105 Torr. Losses after degassing the NS amounted to no more than 0.1 % of its mass. The duration of degassing after thermal stabilization in the chamber lasted 4.5 hours. The tests performed ensured verification of thermal regimes of various components of the spacecraft and onboard equipment in conditions close to their operation in Earth orbit. The results obtained showed the correctness of modeling the main factors of space in thermal cycling and degassing regimes and confirmed the ability of the spacecraft to perform operational functions with stability of parameter values within the limits specified by the regulatory and technical documentation.