MAGIA

The Project, whose phase A was financed by ASI in the frame of the 'Small Missions'  programme started at the end of 2007, concerns a Moon orbiter for scientific purposes. The Prime Contractor was Rheinmetall Italia who subcontracted the satellite design to Spacesys. The Feasibility Study was successfully accomplished in a record time of less than eight  months. The Final Presentation was held in ASI at the  beginning of December 2008. 

The spacecraft body includes three modules: propulsion, service module and payload. The body is covered with solar panels, partly in-orbit deployable. The spacecraft structure was modelized to verify its capability to withstand the severe launch stresses (a  Soyuz launch is envisaged)  and the orbital environment.

 The MAGIA spacecraft is made up by three interconnected modules: the payload module (in red); the truss structure (in light green) holding the propulsion subsystem; and the Service module ( dark green) . The solar array consist of a dorsal panel, two side panels (body-fixed) and two side panels in orbit unfolded. 

Achieving a good spacecraft thermal control was  a challenging task because the spacecraft is subjected to different and time-varyng cold-hot situations (Earth-Moon travel, orbit injection, Moon orbiting) and the payloads performance are very sensitive to the operating temperature range. An accurate modelization led to significantly modify  the spacecraft configuration during the Study 

The thermal analyses were performed at block and unit level. This enabled to spot the main thermal problems related to the spacecraft configuration which was progressively modified to withstand the time and mission-phase variable environmental conditions; and to pinpoint the problems at equipment level and thus to optimize the choice of thermo-optical materials to be used.

The thermal analyses led to in-orbit unfold one half of the dorsal solar array panels to allow heat dissipation by radiation from the service module. The propulsion tanks are protected with superinsulation blankets and decoupled from the other spacecraft structural components. A  dual technology propulsion system  based on hydrazine and cold nitrogen, copes with different mission phases and requirements.

 The Attitude and Orbit control subsystem  faces different requirements during the Earth-Moon transfer and Moon-orbiting phase. It includes:

- four reaction wheels ( around 10 mNm torque) supported by the GN2 thrusters for momentum desaturation and fine attitude changes;

- two star sensors, three rate gyro, several sun sensors  for attitude determination;

- the attitude determination and actuators’ control SW runs in the satellite OBDH

The MAGIA spacecraft carries a 'daughter' subsatellite which will be ejected from the 'mother'  during the Moon-orbiting phase  to perform a gravitometric experiment, and  will be wirelessly linked to the 'mother'.