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Gaia is the new astrometric mission of the European Space Agency. It will measure the positions and proper motions of more than one billion stars and other objects with unprecedented accuracy, providing a sample of more than 1% of the stellar content of our Galaxy. Such a mission implies large technological and design efforts, since it will have to detect, select and measure hundreds of stars every second, sending their data to the Earth - more than 1.5 million kilometers away (1). Thus, the data transmission system must be highly optimized in order to make an efficient use of the downlink. We have focused the master thesis on this aspect; more specifically, we have revised and optimised the existing precompressing algorithms of the different instruments. Also different compression methods are tested in order to increase the final compression ratio. Our main goal is to guarantee the correct transmission of the highest amount of instrument data to the ground station. Therefore, the final ratio is the key factor that shall be analysed here, but CPU consumption and transmission reliability shall be taken into account as well.

This research demonstrated that deformation in this salt province was preferably evacuated to shallow allochthonous salt, leaving welded salt feeders and salt-based detachments. It is proposed that the autochthonous salt basin occupied an area less extensive than previously suggested, reaching a maximum thickness of 1500 m. Finally, structural-sedimentary interplay and hydrocarbon prospectivity of dominant salt and shale-related structures have been discussed. Future exploratory activities have been recommended based on findings and conclusions of this research.

SpaceFibre is a new technology for use onboard spacecraft that provides point-to-point and networked interconnections at 3.125 Gbits/s in flight qualified technology. SpaceFibre is an European Space Agency (ESA) initiative and will substitute the ubiquitous SpaceWire for high speed applications in space. FAPEC is a lossless data compression algorithm that typically offers better ratios than the CCSDS 121.0 Lossless Data Compression Recommendation on realistic data sets. FAPEC was designed for space communications, where requirements are very strong in terms of energy consumption and efficiency. In this project we have demonstrated that FAPEC can be easily integrated on top of SpaceFibre to reduce the amount of information that the spacecraft network has to deal with. The integration of FAPEC with SpaceFibre has successfully been validated in a representative FPGA platform. In the developed design FAPEC operated at ̃12 Msamples/s (̃200 Mbit/s) using a Xilinx Spartan-6 but it is expected to reach Gbit/s speeds with some additional work. The speed of the algorithm has been improved by a factor 6 while the resource usage remains low, around 2% of a Xilinx Virtex-5QV or a Microsemi RTG4. The combination of these two technologies can help to reduce the large amounts of data generated by some satellite instruments in a transparent way, without the need of user intervention, and to provide a solution to the increasing data volumes in spacecrafts. Consequently the combination of FAPEC with SpaceFibre can help to save mass, power consumption and reduce system complexity.