SIRDARIA: A low-cost autonomous deorbiting system for microsatellites

In the last decades the increasing in space activities produced a growth of the space debris. They are mostly concentrated in Low Earth Orbit, (LEO) and Geostationary Earth Orbit, (GEO), since these are the most used region in space activities. The Inter-Agency Space Debris Coordination Committee (IADC) released guidelines which could provide a reduction of debris number uncontrolled growth. The main guideline for LEO satellite suggests reducing mechanical lifetime to 25 years. This paper deals with the design of an autonomous system for deorbiting microsatellites in low earth orbit based on the increasing of ballistic coefficient to reduce satellite life time. A prototype, feasible for small low-cost microsatellites, has been manufactured and is depicted in the paper. This prototype has been subdued to DNEPR launch campaign qualification tests and will be boarded on UNISAT-4, the fourth satellite of the UNISAT program which was established in late nineties from professors, researchers and students of the Group of Astrodynamics of University of Rome (GAUSS) at Scuola di Ingegneria Aerospaziale with the aim to design, realize and operate in orbit small educational satellites. In the framework of this program three satellites have already been launched (UNISAT on September 2000, UNISAT-2 on December 2002 and UNISAT-3 on June 2004 which is still operative) and a fourth satellite, UNISAT-4, to be launched on July 2006. The deorbiting device proposed fulfils with UNISAT programs didactical purposes because a complete space culture cannot ignore the education to the space environment respect.