The fairing and payload are designed to depart from rocket vehicle at
an altitude over 100 km. At this moment, the velocity of rocket vehicle is
about 1900 m/s with a spin of 3 rps. If the departing velocity of fairing is too small, the spin of fairing may cause collision between the fairing
sections and the payload. The collision may induce instability and
unredeemable damage in payload. It is therefore essential to evaluate the
separation mechanisms which are designed to provide sufficient departing
velocities for fairing jettison. In this study, a commercial code RecurDyn is used to establish a dynamic model to simulate the fairing and payload jettison. Simulation is performed under the conditions with and without gravity. Analysis results show that the original design of spring constants is insufficient to safely eject the fairing and collision between fairing sections and payload is inevitable. The increase of spring constants is required to avoid the collision, attenuate the harmonic nutation rate and stabilize the trajectory of payload after jettison.