LEOSTAR: A Small Spacecraft for LEO Communication Missions

This paper outlines the major features of LEOSTAR, a small spacecraft able to support two way data message communications and position reporting missions with a multisatellite constellation. LEOSTAR is a three-axis gravity gradient stabilized satellite. A semi-passive control concept is envisaged with an extensible boom providing attitude stabilization together with three orthogonal Magnetic Torquers, an on-board dedicated computer and other devices. Thrusters provide the station keeping and transfer maneuvers according to an optimized strategy. A bipropellant system with monomethyhl hydrazine as propellant and nitrogen tetroxide as oxidizer is adopted. Large autonomy is envisaged through the adoption of an onboard system management processor. The communications' payload power/mass range from 100 W/40 Kg to 200 W/60 Kg. A payload volume of 0.12 m3 and a maximum antenna dimension of 1 m. are allowed. LEOSTAR is designed to be compatible both with SCOUT and PEGASUS launchers in single or double launch configurations. It can also be launched by large vehicles such ARIANE 4 and Delta in cluster and/or piggy back modes.