The SAOCOM satellites (1A and 1B) are two twin L-band SAR satellites for earth observation. Each satellite weights 3.000kg and main dimensions are 10m wingspan and 3.5m high.
This program is developed by the Argentine Space Agency CONAE as a customer and INVAP as Prime Contractor.
SAOCOM 1A was successfully launched in October 2018 and then began its observation and acquisition phase. Both satellites will operate in a constellation jointly with the four COSMO-SkyMed satellites, developed by Italian Space Agency (ASI). They make up the so-called Italian-Argentine Satellite System for Emergency Management (SIASGE).
During 2017 the SAOCOM 1A assembling, integration and complete qualification test was done at INVAP facilities in Bariloche, where the TVAC test was one of the most challenging test performed by the thermal team.
This presentation shows how the TVAC test of the service platform was carried out, from the point of view of the Thermal Control Subsystem. Key aspects of the thermal balance cases, initial predictions, test results and finally mathematical model correlation are shown.
A second part of the presentation is dedicated to a problem found in the thermal design after the TVAC test during the model correlation. This problem involved a Reaction Control Thruster (RCT) and was particularly interesting because its thermal balance involved a few watts but at the same time it showed a great sensitivity to temperature. Sun trapping due to RCT support MLI configuration and nozzle, in simultaneous with a high resistivity thermal path to satellite structure resulted in a significant over temperature at thruster valve. Some aspects of the troubleshooting sequence are presented, the solution adopted together with some anecdotes and results in flight.