US 5,312,073 AGranted

Method for controlling the pitch attitude of a satellite by means of solar radiation pressure and satellite, in particular an electric propulsion satellite, suitable for implementation of the method

AssigneeAerospatiale Societe Nationale Industrielle

InventorsPatrick Flament, Michel Perdu, Jean Portier, Pierre Brunet

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Abstract

A satellite embodying at least one surface intended mainly for exposure to solar radiation and extending away from the satellite in a predetermined direction (Y), an on-board computer having connected thereto an attitude sensing system, an orbit control system for imparting thrust to the satellite along predetermined axes, and an attitude control system. The satellite further embodies a device for controlling the tilt of the surface in parallel with a plurality of planes containing the predetermined direction; and, therefore, particularly in parallel with the plane of a solar panel forming the surface. The tilt control device is controlled by the on-board computer. The tilting can generate a moment of pitch or relocate the center of gravity onto the axis of the orbit control system.

Claims32

Dependent claims

An attitude control system for a satellite, said attitude control system comprising:

a satellite having attitude stabilizing means for controlling said attitude about a pitch, yaw and roll axis while said satellite is in a geostationary orbit;
an onboard computer mounted to said satellite, said attitude stabilizing means being in communication with said onboard computer;
at least one surface member extending from said satellite in a first direction away from said satellite, said at least one surface member adapted to be exposed to solar radiation;
orbit control means mounted to said satellite for applying to said satellite thrusts along said pitch, yaw and roll axis;
said orbit control means further comprising thruster means symmetrically spaced about said pitch and yaw axis;
said thruster means being inclined at a predetermined angle at least with respect to said pitch axis such that a resultant force vector of said thrusts generated by said thruster means is in a first resultant force direction;
and
moving means mounted to said satellite for moving said at lest one surface member with respect to said satellite whereby the movement of said at least one surface member causes the center of gravity of said satellite to shift from a first position to a second position such that said first resultant force direction of the vector generated by said thruster means acts through aid second position of said center of gravity.

5 more elements

A satellite adapted to be stabilized in attitude about roll, yaw and pitch axes in an at least approximately circular terrestrial orbit, said satellite comprising:

a body having North and South sides;
an attitude sensor system mounted to said body;
an onboard computer in communication with said attitude sensor system;
at least one solar generator panel member extending substantially parallel to said pitch axis adapted to be exposed to solar radiation;
means coupled to said body and said at least one solar generator panel member for rotating said at least one solar generator panel member about said pitch axis, said rotating means being controlled by said onboard computer so as to remain at least approximately perpendicular to said solar radiation;
a kinetic energy storage system in communication with said onboard computer;
an attitude control and orbit correction propulsion system in communication with said onboard computer, said attitude control and orbit correction propulsion system being exclusively electrical and comprising a first pair of electric thrusters disposed substantially symmetrically relative to a plane including said pitch and yaw axes, said first pair of electrical thrusters being inclined relative to a plane including said roll and yaw axes, an further being inclined relative to said plane including said pitch and yaw axes and still further being inclined not more than approximately 20.degree. relative to plane including said roll and pitch axes such that a resultant force vector of said first pair of electric thrusters is in a first resultant force direction;
and
first means mounted to said body for tilting said at least one solar generator panel member relative to said pitch axis whereby the tilting of said at least one solar generator panel member causes the center of gravity of said satellite to shift from a first position to a second position such that said first resultant force direction of the vector generated by said first pair of electric thrusters acts through said second position of said center of gravity, said first tilting means being controlled by said onboard computer.

6 more elements

Dependencies are inferred from the claim text.