Rosetta - Evaluation of Sun Interference during LEOP

The Rosetta mission due for launch in January 2002 has been delayed as precautionary measure after the failure of the previous launch with the European Ariane 5 launcher. Due to that, a new mission plan targeting comet Churyumov-Gerasimenko (C-G) instead of the initially baselined Wirtanen, has been devised. For the new trajectory and launch window, it is possible that the angular offset between the probe and the Sun becomes as small as 1 deg. The present paper describes the computation of the effects of the thermal noise generated by the Sun at the ground station antenna, the options identified to minimise the problem including launching the spacecraft in the opposite direction and the final mission operation profile selected.