Polar Platform Introduction

The Polar Platform (PPF) represents, with its payload, the largest European satellite undertaken so far. It was conceived as a multimission platform which can accommodate a number of different missions. The Polar Platform is comprised of two major modules:

• The service module (SM, see below), the design of which is largely derived from SPOT 4, provides the main satellite support functions, such as command and control, communications with the ground, power, attitude and orbit control, and propulsion. It also interfaces with the launcher, Ariane 5.
• The payload module (PLM, see below), on which the Envisat instruments and PPF payload support equipment (data management and communications, electrical distribution) are accommodated.

This split provides the basis for a convenient physical and functional separation between the SM subsystems and equipment which are needed for every mission, and those in the PLM which are mission-specific and therefore dedicated only to the needs of the particular payload complement being flown. In addition, the interface decoupling at module level facilitates parallel development and integration of service and payload modules, and allows for a schedule-efficient satellite integration programme where only the minimum of system level activities is needed for final verification. A structural model programme has been performed with both modules coupled and representative instrument models also included, as seen here during integration and in the acoustic test chamber.

  An indication of the size differences.

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry