The SPOT 5 AOCS in orbit performances

SPOT 5 is the latest in a series of CNES satellites designed to fulfill an Earth observation and imaging mission. SPOT 5 is positioned on a Sun-synchronous orbit. It carries an optical observation payload featuring an image resolution one order of magnitude better than its predecessors Spot 3 and Spot 4. SPOT 5 has been successfully launched on an Ariane 4 on May 4(th) 2002. The first part of this paper summarizes the major characteristics of the SPOT5 Attitude and Orbit Control System (AOCS). The second part of the paper presents the actual behaviour of the AOCS during the Launch and Early Operation Phases. The behaviour of the AOCS will be illustrated from actual flight telemetry data. In particular, the operation sequence of the commissioning phase will be presented. It includes: the smooth behaviour of the Rate Reduction Mode, for an in orbit injection very close to the expected optimum values, the Earth acquisition, performed in about 2 minutes, the Solar Array deployment phase, with the nominally expected resulting attitude perturbations, the next re-acquisition phase to converge into the operational mode, the attitude update using the Star Sensor units.