Abstract: A rocket engine feed system, includes a feed circuit including a device for varying a gas volume in the feed circuit to suppress the POGO effect. A method of suppressing the POGO effect varies at least one hydraulic resonant frequency by varying a rate at which gas is injected into the feed circuit.

Abstract: A system and method for detecting and locating an insulation flaw in a solar generator on a spacecraft. The solar generator comprises a plurality of flaps. Each flap bears at least one solar cell that is connected to an electrical distribution network and electrically insulated from the flap. Each flap is connected, by a first load and by a second load, to a first electrical line and a second electrical line, respectively. The ratio of the impedances of the first load and of the second load of a flap being denoted as an impedance ratio of the flap. The solar generator comprises at least two flaps exhibiting different respective impedance ratios. The system comprises a component for evaluating the currents flowing in the first and second electrical lines, and a detector for detecting and locating an insulation flaw in the solar generator based on the evaluations of the currents.

Abstract: A paste kneading device includes an oblong barrel, two shafts arranged parallel within the barrel, being held and driven at their first ends, defining an upstream end, by a drive device, two screws each formed by threads carried by the shafts, each screw having a transport section carrying a main thread to cause the paste to advance along the two screws, and an outlet orifice formed in the wall of the barrel to discharge the kneaded paste, the kneading device further including a holder device to hold each shaft at its second end, defining a downstream end, and enabling the shaft to rotate freely, the holder device including, for each shaft, a first portion secured to the shaft and a second portion secured to a cap end portion of the barrel, the cap end portion being removable and the first and second portions being configured to engage and disengage freely.

Abstract: The present invention relates to an in-service reconfigurable antenna reflector comprising a rigid support and a membrane, deformable and having radio-electric reflectivity properties. According to the invention, the reflector comprises a plurality of coupling means connecting the rigid support and the membrane, comprising a first link of finger ball joint type connected to the rigid support, and a second link of finger ball joint type connected to the membrane. Each coupling means furthermore comprises a linear actuator, comprising a rotary motor and a screw-nut assembly, connected to the two links of finger ball joint type, and able to generate, in an operational configuration, a translational motion allowing the deformation of the membrane.

Abstract: A method includes estimating a position of a receiver, aboard a moving object, on the basis of the navigation signals emitted by satellites received by an antenna in an antenna array placed on the moving object, and using a three-dimensional geographical map to deduce, geometrically, on the basis of the position of the receiver and of a ray casting starting from the receiver, the number of paths reflected on walls of buildings present in a scene corresponding to an environment surrounding the receiver. The determined number of reflected paths is used to initialize an algorithm for estimating angles of arrival of multi-paths to deduce therefrom angles of arrival of the paths reflected on the walls before reaching the receiver. Optionally, the method can comprise making it possible to bound the distance information error due to a multi-path to render the estimation of direction of arrival of the signals more efficacious.

Abstract: A method of manufacturing a radiation-resistant optical fiber and a thus-obtained radiation-resistant optical fiber, the method includes the following steps: a) manufacturing a silica optical fiber preform; b) forming, in the preform, a longitudinal cavity; c) drawing the preform so as to form an optical fiber (1) including a core (2), an optical cladding (6) and at least one longitudinal cavity (3) having at least one opening (13) at one end of the optical fiber (1); d) applying, during step c) of fiber drawing, a gas-tight coating (4); e) exposing the optical fiber (1) to a gaseous substance, including preferably gaseous hydrogen and/or gaseous deuterium, in such a way to incorporate the gaseous substance in silica via the opening (13); and f) closing any opening (13) at both ends of the optical fiber.

Abstract: The invention relates mainly to a test bench (10) for a radial bearing (14) suitable for being interposed between two members (12, 16) that are movable relative to each other in rotation, the test bench being characterized in that it comprises a radial force measurement device (18) for measuring radial forces exerted on said bearing (14), a radial acceleration measurement device (20) for measuring radial accelerations to which said bearing (14) is subjected, and an electronic calculation unit (26) in communication with the radial force measurement device (18) and with the radial acceleration measurement device (20). The invention also relates to a method of establishing a behavior relationship for the radial bearing (14).

Abstract: A cooling method for cooling a device connected to a cryogenic tank via a main admission duct for feeding the device with cryogenic fluid once the device is cooled. In contrast, during cooling, a cryogenic fluid is introduced into the device via a cooling admission duct that is different from the main admission duct and that presents a flow section that is narrower than the flow section of the main admission duct.

Abstract: A multiple-reflector antenna for telecommunications satellites including a shaft, to which are attached at least two sub-reflectors, rotating in relation to a load-bearing structure, and a motor including a rotor able to drive the shaft in rotation, and a stator attached to the load-bearing structure, wherein the multiple-reflector antenna also includes two bearings enabling the shaft to rotate in relation to the load-bearing structure, a torsionally rigid mechanical filter placed between the shaft and the rotor, enabling the rotor to transmit the rotational movement to the shaft, and able to dampen the stresses generated by the shaft on the motor, and locking means able to hold the angular position of the shaft in relation to the load-bearing structure.

Abstract: A method for identifying transmitters by a terminal in a single-frequency network comprising a plurality of transmitters. The transmitters are synchronized and transmit with an artificial delay ?i, specific to each transmitter. The method comprises at least one step of acquiring the approximate position of the terminal {circumflex over (p)}, the position pi of a list of transmitters {Tx} in the vicinity of the terminal and the delays ?i associated with them, a step of measuring pseudo-distances ?i between the transmitters and the terminal and a step of associating the measurements ?i with the transmitters of known positions pi by minimizing a cost function, said cost function ?(?i,{circumflex over (p)},?) corresponding to the norm of the error between the measurements ?i and a model of measurements of the pseudo-distances applied to a permutation of the position of the transmitters ?.

Abstract: A device includes at least one built-in flexible portion (1) between two stiffer portions (10) that are made of a stiff composite material, the flexible portion (11) being suitable for forming a flexible hinge and made of a flexible material including a reinforcing armature that includes at least one connecting layer (13) common to the material(s) forming each stiff portion (10). The device has end surfaces (20) that oppose each other when extended, the opposing end surfaces being arranged to be suited to serve as a longitudinal compression abutment while enabling the thus-made hinge to fold back at least in a direction away from the extended state.

Abstract: A method of acquiring, compressing and transmitting satellite images, characterized in that in a systematic manner: an image is acquired (101); (102) the image is processed by an image preprocessing step providing a value characteristic of the image and an image preprocessed by recognizing predetermined natural objects in the acquired image and replacing the natural objects by standard objects; the characteristic value is compared (103) with a table of values, each value of which is associated with a compression algorithm; the compression algorithm corresponding to the characteristic value is implemented (104) by compression elements for compressing the image; the compressed image is transmitted (105) to a remote image reception device by transmission elements.

Abstract: Optical devices can comprise a deformable mirror and a system for deforming said mirror. A deformation system comprises a first mechanical structure comprising a first surround, one or more electromechanical actuators attached to the first mechanical structure, a second mechanical structure comprising a substantially planar bottom and a second surround, both deformable, the bottom being attached to the first surround, the second surround being attached to the surround of the mirror, a rigid stud being attached to the bottom, substantially planar and centerd on the bottom, the electromechanical actuator or actuators exerting predetermined forces or bending moments on the stud so as to generate a particular distribution of the bending moments on the surround of the mirror, deforming it according to a geometrical form representative or of one or more predetermined geometrical aberrations.

Abstract: The invention relates mainly to a test bench (10) for a radial bearing (14) suitable for being interposed between two members (12, 16) that are movable relative to each other in rotation, the test bench being characterized in that it comprises a radial force measurement device (18) for measuring radial forces exerted on said bearing (14), a radial acceleration measurement device (20) for measuring radial accelerations to which said bearing (14) is subjected, and an electronic calculation unit (26) in communication with the radial force measurement device (18) and with the radial acceleration measurement device (20). The invention also relates to a method of establishing a behavior relationship for the radial bearing (14).

Abstract: A system and method for detecting and locating an insulation flaw in a solar generator on a spacecraft. The solar generator comprises a plurality of flaps. Each flap bears at least one solar cell that is connected to an electrical distribution network and electrically insulated from the flap. Each flap is connected, by a first load and by a second load, to a first electrical line and a second electrical line, respectively. The ratio of the impedances of the first load and of the second load of a flap being denoted as an impedance ratio of the flap. The solar generator comprises at least two flaps exhibiting different respective impedance ratios. The system comprises a component for evaluating the currents flowing in the first and second electrical lines, and a detector for detecting and locating an insulation flaw in the solar generator based on the evaluations of the currents.

Abstract: A rocket engine feed system, includes a feed circuit including a device for varying a gas volume in the feed circuit to suppress the POGO effect. A method of suppressing the POGO effect varies at least one hydraulic resonant frequency by varying a rate at which gas is injected into the feed circuit.

Abstract: A method includes estimating a position of a receiver, aboard a moving object, on the basis of the navigation signals emitted by satellites received by an antenna in an antenna array placed on the moving object, and using a three-dimensional geographical map to deduce, geometrically, on the basis of the position of the receiver and of a ray casting starting from the receiver, the number of paths reflected on walls of buildings present in a scene corresponding to an environment surrounding the receiver. The determined number of reflected paths is used to initialize an algorithm for estimating angles of arrival of multi-paths to deduce therefrom angles of arrival of the paths reflected on the walls before reaching the receiver. Optionally, the method can comprise making it possible to bound the distance information error due to a multi-path to render the estimation of direction of arrival of the signals more efficacious.

Abstract: A device, referred to as a satellite grid, includes a plurality of reception and storage ground stations (5) provided with a storage unit (13), each station (5) including elements for receiving observation data from at least one satellite orbiting around the Earth. Each station (5) is connected to at least one digital network (15) and includes at least one management module so that the different stations cooperate together in order to provide a permanent and transparent shared access to the observation data coming from at least one satellite and stored in the different stations (5), wherein the satellite grid is adapted to be accessible and viewed as a single computer resource from any access point in the network (15).

Abstract: A multiple-reflector antenna for telecommunications satellites including a shaft, to which are attached at least two sub-reflectors, rotating in relation to a load-bearing structure, and a motor including a rotor able to drive the shaft in rotation, and a stator attached to the load-bearing structure, wherein the multiple-reflector antenna also includes two bearings enabling the shaft to rotate in relation to the load-bearing structure, a torsionally rigid mechanical filter placed between the shaft and the rotor, enabling the rotor to transmit the rotational movement to the shaft, and able to dampen the stresses generated by the shaft on the motor, and locking means able to hold the angular position of the shaft in relation to the load-bearing structure.

Abstract: The present invention relates to an in-service reconfigurable antenna reflector comprising a rigid support and a membrane, deformable and having radio-electric reflectivity properties. According to the invention, the reflector comprises a plurality of coupling means connecting the rigid support and the membrane, comprising a first link of finger ball joint type connected to the rigid support, and a second link of finger ball joint type connected to the membrane. Each coupling means furthermore comprises a linear actuator, comprising a rotary motor and a screw-nut assembly, connected to the two links of finger ball joint type, and able to generate, in an operational configuration, a translational motion allowing the deformation of the membrane.