The PLATO Payload Module – here still the model – with 26 cameras. Note the relative pointing of each of the 4 groups of 6 normal cameras, and the two fast cameras located in the top row.
The scientific requirement to discover and characterise a large number of Earth-sized planets orbiting bright stars was a key factor int the design of the PLATO payload module. The telescope employs a new modular design comprising 26 cameras. This provides a wide field-of-view (FoV) to maximize the number of sparsely distributed bright stars in the sky with one pointing, whilst simultaneously covering a large portion of the sky. In addition, it provides the photometric accuracy required to detect Earth-sized planets and a high photometric dynamic range, allowing astronomers to observe bright stars (mV < 11) as well as fainter stars down to V-magnitude of 16. These requirements are met by the innovative multi-camera concept.
There are two types of cameras: 24 ‘normal’ cameras (N-CAM) and two ‘fast’ cameras (F-CAM) with their corresponding electronic units (Ancillary Electronic Unit, AEU) and the data processing system (DPS). The cameras are mounted on an optical bench, which is mounted on the satellite bus. The electronic units are housed separately from the cameras within the satellite structure.
The N-CAMs operate at a nominal cadence of 25 s and will observe stars fainter than magnitude 8. Photometry of saturated stars down to magnitude 4 will be possible.
The F-CAMs operate at a cadence of 2.5 s and primarily observe stars in the magnitude range from 4 to 8. They are used for satellite tracking (Fine Guidance Sensors, FGS). Each camera is equipped with its own CCD focal plane array, consisting of four CCDs from Teledyne e2v. The ‘normal’ cameras operate in full-frame mode with an effective field of view of ~1037 square degrees, whilst the two high-speed cameras operate in frame-transfer mode with a field of view of ~610 square degrees.
PLATO satellite and its main modules
Exploded view of the satellite with payload module and service module
