CONSTELLATION OF CUBESATS: 3-STAR IN THE HUMSAT/GEOID MISSION

摘要

The 3-STAR program is the new cubesat educational project at the Politecnico di Torino. It has been thought inresponse to the GEOID call for proposals issued by the Education Office of the European Space Agency. TheGEOID (GENSO Experimental Orbital Initial Demonstration) initiative wants to settle an orbiting constellation ofcubesats to be operated by the GENSO (Global Educational Network for Satellite Operations) ground-stationsnetwork. GEOID is expected to be the communication backbone of the initial version of the HUMSAT system. Themain goal of HUMSAT is to use the constellation of satellites and the GENSO ground stations, to provide supportfor humanitarian initiatives, especially in developing areas or areas without infrastructure. The 3-STAR will be oneof the nine cubesats in the GEOID constellation. It will be a 3U cubesat derived from the e-st@r cubesat experience.In addition, it will carry two payloads: the HumSat payload, consisting of a simple but extremely reliablecommunication module compatible with the elements of the HUMSAT system, and the P-GRESSION (Payload forGNSS remote sensing and signal detection) payload. The P-GRESSION payload aims at performing measurementsby means of radio-occultation technique and scattering theory, using GNSS signals. In this paper the 3-STARproject is described together with a preliminary assessment on the performances of the GEOID/HUMSATconstellation. The main requirements of the GEOID/HUMSAT project have been used to drive an optimizationprocess aimed at determining the best configurations of a swarm-like constellation of cubesats. The mission scenariois made of the nine GEOID cubesats, a number of GENSO ground nodes and several sensors distributed on theEarth surface. The results of the analysis demonstrate that the aspects related to the cubesat-system design cannot bedecoupled from the design of the constellation, not even in a preliminary phase. Further, it is demonstrated that theperformances of a swarm-like constellation are comparable to those of a well-distributed one.