The onboard data handling subsystem (OBDH) executes uplinked telecommands, keeps a check on satellite systems, and performs attitude and orbit control and housekeeping functions (electrical power, etc.).

The satellite is controlled by central flight software running on an onboard computer (OBC) built around a Marconi MDC 31750 processor. This software dialogues with all the satellite's systems.

A decoding and reconfiguration unit operates alongside the OBC. This unit decodes uplinked telecommands and monitors and reconfigures critical systems such as the OBC itself.

The satellite's daily work schedule is set by the list of telecommands containing programming instructions received from the Operations Control Centre (CMP). The flight software commands the instruments to acquire imagery requested by customers when the satellite passes over the target area.

A key function of the OBDH is to keep a check on the satellite's systems to ensure that they are functioning correctly. In some cases, it may partially reconfigure systems to avert degradation of the mission. If a failure is detected, the flight software maintains the satellite's vital functions using back-up systems if necessary. The flight software does not locate malfunctioning devices and in such cases image acquisition cannot continue without the intervention of the CMP. The software signals anomalies and supplies the data for engineers at the CMP to locate a malfunctioning device.