Numerical simulation of Ulysses nutation

A numerical simulation has been performed on the in-orbit instability of the Ulysses Spacecraft. The thermal excitation from the solar flux, the flexible axial boom and its deployment mechanism have been modeled and analyzed. The simulation shows that the nutation build-up has been originated by the solar input on the axial boom coupled with the system nutation frequency of the spacecraft. The results agree with the observed behavior.