CNES Miniaturization Policy: An Answer to Nanosatellites Challenges

The reduction of mass and size with improvement of the performance of a device is a permanent challenge for the space industry. The French National Space Agency has funded hundreds of R&D activities in the past, in all dedicated technical areas to facilitate these kind of technological evolution. Miniaturization efforts have, more recently, encountered a growing field of application, the one of Nanosatellites. For these applications, performance/cost trade-off is largely dominated by full cost, that is to say the cost including the entire satellite system development, from the initial idea to the end of life, including operations, data processing and its distribution. The carried out trade-offs are therefore based on a different constraints environment, in which the risk variable is systematically re-evaluated considering the cost/performance couple; the methods, the development process and the planning of delivery being directly impacted by this challenge. In this logic, and while continuing its efforts to miniaturize and improve performance for conventional markets (Earth observation, science, telecommunications, ...), CNES has adapted its working environment around the Nanosats domain to accelerate the development of adapted solutions. This adaptation being made both in terms of new development processes and of use of new COTS technology for equipment themselves. Moreover, projects in New Space are changing the historical relationship between CNES and its industrial partners and are encouraging a transition from a client/provider approach to a more co-partners approach. The objective of success for both parties implies active collaboration. Together, CNES and industrials manage to anticipate difficulties and accelerate project schedule. The article presents the state of the current activities around the Nanosat environment by specifying the origin of these activities and the trends that are pursued for the future

Biogeochemical flux associated to pearl farming activity and ecological consequences on water-column

International audienc

Contaminated sediment resuspension induces shifts in phytoplankton structure and function in a eutrophic Mediterranean lagoon

International audienc

Consequences of contamination on the interactions between phytoplankton and bacterioplankton

Sediment resuspension can provoke strong water enrichment in nutrients, contaminants, and microorganisms. Microcosm incubations were performed in triplicate for 96 h, with lagoon and offshore waters incubated either with sediment elutriate or with an artificial mixture of contaminants issued from sediment resuspension. Sediment elutriate provoked a strong increase in microbial biomass, with little effects on the phytoplankton and bacterioplankton community structures. Among the pool of contaminants released, few were clearly identified as structuring factors of phytoplanktdn and bacterioplankton communities, namely simazine, Cu, Sn, Ni, and Cr. Effects were more pronounced in the offshore waters, suggesting a relative tolerance of the lagoon microbial communities to contamination. The impacts of contamination on the microbial community structure were direct or indirect, depending on the nature and the strength of the interactions between phytoplankton and bacterioplankton

Do the levels of industrial pollutants influence the distribution and abundance of dinoflagellate cysts in the recently-deposited sediment of a Mediterranean coastal ecosystem ?

We studied the relationships between sediment industrial pollutants concentrations, sediment characteristics and the dinoflagellate cyst abundance within a coastal lagoon by investigating a total of 55 sampling stations within the Bizerte lagoon, a highly anthropized Mediterranean ecosystem. The sediment of Bizerte lagoon is characterized by a high dinocyst abundance, reaching a maximum value of 2742 cysts.g(-1) of dry sediment. The investigated cyst diversity was characterized by the presence of 22 dominant dinocyst morphotypes belonging to 11 genera. Two dinoflagellate species dominated the assemblage: Alexandrium pseudogonyaulax and Protoperidinium claudicans, representing 29 to 89% and 5 to 38% of the total cyst abundance, respectively, depending on the station. Seven morphotypes belonging to potentially toxic species were detected, including Alexandrium minutum, A. pseudogonyaulax, Alexandrium catenella/tamarense species complex, Lingulodinium polyedrum, Gonyaulax cf. spinifera complex, Prorocentrum micans and Protoceratium reticulatum. Pearson correlation values showed a positive correlation (alpha = 0.05) between cyst abundance and both water content and fine silt sediment content. Clustering revealed that the highest abundance of cysts corresponds to stations presenting the higher amounts of heavy metals. The simultaneous autoregressive model (SAM) highlighted a significant correlation (alpha = 0.05) between cyst accumulation and two main factors: sediment water content and sediment content for several heavy metals, including Hg, Cd, Cu, Ni and Cr. These results suggest that the degree of heavy metal pollution could influence cyst accumulation patterns