Preliminary Study of the Trajectory Design for SPICA Mission

Dr. Masaki Nakamiya, Institute of Space & Astronautical Science / Japan Aerospace Exploration Agency (ISAS/JAXA)

We studied the preliminary mission design for the next-generation infrared mission of JAXA, SPICA (Space Infrared Telescope for Cosmology and Astrophysics), which is to be launched into the Sun-Earth L2 Halo orbit. In this preliminary study, two tasks were conducted.

Firstly, we designed the nominal transfer orbits from the Earth to the Halo orbit and analyzed the required Delta-V and flight time for the transfer. Secondly, we examined the impact of translational force, which is caused by the thruster unloading for an accumulated angular momentum on spacecraft reaction wheels in the attitude control from the viewpoint of the station keeping.

From this study, we observed that the launch window could be expanded by varying the size of the nominal Halo orbit with the stable manifolds, and the deviations arising from the unloading Delta-V could be decreased by selecting the attitude of the spacecraft appropriately during the unloading operation.