The GAIA mission will allow the creation of a precise 3D map of about 1 billion stars in our galaxy and beyond. In the process, it will also map their motions, which encode the origin and subsequent evolution of the galaxy.

Mass Memory space system

The PDHU (Payload Data Handling Unit) is responsible for storing all scientific data (from seven video processing units) and sending them back, on request, to Earth. This unit is fully under Syderal's responsibility.

The PDHU includes:

  • 1 Tbits memory
  • File Management System
  • Two independent CAN controller & interface bus
  • 7 x SpaceWire links inputs @ 40 Mbits/ sec with the Video Processing Units
  • 2 x Packet Wire links outputs @ 10 Mbits/ sec
  • Processor board based on LEON 2 FT
  • MIL-STD-1553B interface with the CDMU

The main critical functions are:

  • Routing of the scientific data @ 280 Mbits/sec
  • Reliability higher than 98 % until end-of-life (15 years)
  • Pure radiative thermal dissipation
  • Scalability of the memory size

Swiss Quality

The GAIA mass memory is one of the largest ones developed for a scientific mission. We are proud to say that led by Syderal, who was the prime contractor, it is also the first one to be realised by an industrial consortium.

Engineering talent

The PDHU has been recognised as one of the most challenging electronic equipment of the GAIA satellite. The sophisticated design, development, manufacturing and testing of the equipment have led to the successful resolution of some major technical issues like the integration of 7 SpaceWire IP Cores within a single FPGA.


Fully functional since the middle of 2014, the PDHU has already provided high quality images which allowed for the discovery of a first stellar explosion in another galaxy 500 million light-years away. Currently at 1.2 million kms from Earth, the PDHU will deliver Petabyte of data during the complete mission.