Airbus Defence and Space Sas

Centre National Detudes Spatiales

Astrium Sas

Jean Sperandei

Kristen Lagadec

Philippe Laurens

Gilles Pupille

Gilles Planche

Nicolas Cuilleron

Claire Roche

A combined system for imaging and communication by laser signals including a telescope () in which the primary () and secondary () mirrors are shared between an imaging function and a function involving the emission of laser transmission signals. The accuracy required for the direction of emission (DE) of the laser transmission signals is obtained by additionally placing a geolocation device on board a satellite carrying the combined system. No coarse pointing assembly is used and it is also possible for the system to be devoid of any fine pointing assembly and target acquisition and tracking detector.

Combined imaging and laser communication system

A method to control a sunlight acquisition phase of a spacecraft with a nonzero angular momentum of an axis D. The spacecraft includes a solar generator configured to rotate about an axis Y. The spacecraft actuators are controlled to place the spacecraft in an intermediate orientation in which the axis Y is substantially orthogonal to the axis D. The solar generator is controlled to orientate the solar generator towards the sun. The spacecraft actuators are controlled to reduce the angular momentum of the spacecraft. The actuators of the spacecraft engine are controlled to place the spacecraft in an acquisition orientation in which the axis Y is substantially orthogonal to the direction of the sun with respect to the spacecraft.

Method and device for control of a sunlight acquisition phase of a spacecraft

A method for controlling an attitude control system () for a space vehicle (), the attitude of the space vehicle being controlled during at least one preparation phase followed by an observation phase during which an image capture is performed. In an attitude control system that includes a maneuvering subsystem () which includes at least one reaction wheel, the method includes, during the at least one preparation phase, a preparation step (), during which commands are issued to the maneuvering subsystem in order to control the attitude of the space vehicle, followed by a step () of stopping the at least one reaction wheel prior to the observation phase. In addition, during the observation phase, a fine control subsystem () having a lower vibration signature than that of the maneuvering subsystem, is sent commands in order to control the space vehicle's attitude. An attitude control system for a space vehicle is also described.

Method of commanding an attitude control system and attitude control system of a space vehicle

An electric motor () with permanent magnets includes a rotor (), on which permanent magnets are fastened (), and a stator (). The stator includes a stator structure and coils () installed on the stator structure. The stator structure is realized by an assembly of at least three independent stator elements (), assembled on a baseplate () with no direct mechanical linkage between them. Each stator element () is fastened onto the baseplate () of the motor by an adjusted fastener () and at least one anti-rotation element (). Preferably, the stator elements () are made of a material that is a good heat conductor and electrical insulator, such as a ceramic.

Permanent-magnet electric motor comprising a segmented stator

An attitude control actuator of a spacecraft includes a first momentum wheel driven in rotation by a motor and a second momentum wheel. Both momentum wheels are movable in rotation about an axis and are mechanically coupled by coupling means imposing between a rotation speed &#x3c9;of the first momentum wheel and a rotation speed &#x3c9;of the second momentum wheel a ratio R=&#x3c9;, negative on the one hand and continuously modifiable by the coupling means in response to a command on the other hand so as to modify the total angular momentum of the actuator while the total kinetic energy of the wheels are kept constant. In one embodiment, both momentum wheels have the same inertia and are coupled through a toroidal variable rotation speed drive, where ratio R varies between &#x2212;3 and &#x2212;&#x2153;. The motor drives the momentum wheels and operates as a generator for braking the momentum wheels.

Actuator with transfer of angular momentum for the attitude control of a spacecraft

An actuator device for varying the attitude of a spacecraft includes a reversible conversion chain of electrical energy to mechanical rotation energy of a flywheel. The electrical energy is stored in a capacitive element that may be a supercapacitor. The actuator device also includes an electrical power converter, connected, on one hand, to the capacitive element and intended to be connected, on the other hand, to the spacecraft power bus. The converter makes it possible to compensate for losses to keep a total energy of the actuator device constant.

Growing community of inventors

Toulouse, France

Jean Sperandei