Matra

About: Matra is a based out in . It is known for research contribution in the topics: Signal & Detector. The organization has 1330 authors who have published 1216 publications receiving 17967 citations.

Pneumatic regulating pressure reducing valve

Abstract: In a pneumatic pressure-reducer, the control rod for the control valve is supported and guided by two spring washers whose radial stiffness is at least around 200 times greater than the axial stiffness. Each washer comprises internal and external annular regions connected by at least three inclined arms, separated by openings. Preferably, a restriction is formed between a region of the pressure-reducer situated downstream from the valve and a comparison chamber, the pressure of which acts on a comparison capsule connected to the rod.

Tools for Operations Preparation and Automation: The Opsware Approach

Abstract: The automation of ground operations is a key issue for reducing exploitation costs of satellite systems while improving safety and availability of the provided service. Many operations managers are considering the implementation of new functions for automating operations. Their motivations can be separated in two classes: minimize the staff or operate more satellites with the same staff, and thus reduce exploitation costs. For this purpose, automated operations allow an optimized off-line preparation of operations by experts during working hours, and they relieve operators from routine or time-consuming tasks (detailed monitoring of parameters, preparation and release of commands, ground station management) improve safety of operations and availability of the space system. For this purpose, automated operations reduce the risk of human errors (a common cause of service interruption) thanks to a complete, rigorous, repetitive and fast execution of planned operations. Moreover they allow a larger number of verifications, a reduced reaction time upon anomalies and a dynamic optimization given the available ground and space resources.

The scientific payload of the HIPPARCOS astrometry satellite

Abstract: The HIPPARCOS Satellite, a project of the European Space Agency, developed by European Industry led by MATRA, is devoted to astrometry with the ultimate goal of allowing the establishment of a catalogue of stellar astrometric parameters of some 100 000 stars to an accuracy of 2 milliarc-seconds. Whereas the overall aspects of the Hipparcos mission and the design of the platform are presented separately by E. Zeis et al (1) and M. Le Moine et al (2), the present paper deals with a description of the scientific payload of the satellite. The principle of the payload is outlined covering all major design features associated with the optical telescope. The configuration is described in some detail together with the necessary resources. The next section is devoted to a review of the performances required from the payload. The instrumental parameters are recalled, followed by a survey of the mission related performances such as an extreme mechanical and thermal stability, and the very high optical quality of the mirrors. The hardware and associated technology are then described in detail since they are believed to represent in many areas a major challenge for European industry. The status of development is presented for key items such as the Beam Combiner, the Optics, the focal plane modulating grid, and the thermo-mechanical hardware. Finally, the industrial organization is briefly recalled together with the development approach which has been adopted. Since the verification of performances in such a demanding project is essential to the success of the mission, the main performance tests and associated ground support equipment are also presented.

Continuous transport system for trains with programmed vehicles

Abstract: A continuous transport system for trains with programmed vehicles. The system comprises at each station a connection track (H10, H20, H11, H21, H13, H23) linking the outward track (OX) to the return track (X''O'') or conversely, to enable a train travelling from a high density traffic area to a less dense traffic area, to reduce the number of its vehicles and, to enable a train travelling in the opposite direction to recover vehicles. The system for transporting persons comprises a minimum number of vehicles to ensure maximum flow.