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Abstract: Attitude dynamics of the first Russian nanosatellite TNS-0 is considered. The satellite is equipped with an attitude control system comprising a strong permanent magnet mounted along the satellite axis of symmetry and a number of hysteresis rods as a damper. It was expected that the satellite axis of symmetry traces the induction vector of the geomagnetic field. When the satellite has been orbited its angular momentum was unexpectedly high. To interpret motion of the satellite using mathematical study and flight data processing is the purpose of this paper. Three elementary sun sensors are installed on the satellite corp and their measurements analysis shows that the satellite angular velocity was decreasing with a time early in the mission. The analytical study of the motion is carried out. To examine the asymptotical stability of the motion the approximating model of the hysteresis was involved. Finally, the satellite probably reached the following motion: it rotates; the magnet direction precession-averaged follows the induction vector of the geomagnetic field; the angle between the magnet and the induction vector is not rather small and without tendency to be smaller. Actually, the satellite reached a permanent rotation mode almost without energy dissipation. Such a mode was mentioned in the 1960s and now it is explained and recognized in flight. [Copyright &y& Elsevier]

Abstract: Myriade is a recent multipurpose flight proven platform developed by the Centre National d’Etudes Spatiales (CNES) in partnership with the industry. The 60kg platform can accommodate any kind of payload (optical, radar, telecom, etc.), up to of mass. Up to now, as many as 16 satellites based on the Myriade platform have been launched, or are under development, under the Prime Contractorship of CNES (four satellites, scientific applications) or Astrium (12 satellites, high resolution earth observation, or military demonstration). The payloads are various and encompass all applications. This record makes the Myriade platform a real success, and probably the most efficient LEO platform product line ever developed in Europe. It is a candidate worth considering when planning missions and at the same time ambitious, operational, and affordable. Six satellites have been launched and show in-orbit behaviour which exceeds expectation. Astrium has a unique experience on the Myriade product line, gained through an efficient and successful partnership with CNES materialized by the prime contractorship of 12 Myriade based satellites for several customers. This paper recalls the missions and presents analysis about the success criteria of such a product line. A conclusion shall be proposed to highlight what could be the next step of this success story. [Copyright &y& Elsevier]