Extendable structure forming an antenna provided with a solar generator for a satellite

The invention lies in the field of deployable structures that can equip satellites. It relates to such a deployable structure consisting of panels forming an antenna equipped with a solar generator.

Satellites are used in particular as radar systems. They comprise for this purpose a radar antenna in the form of a flat panel in operating configuration. This panel plane typically has dimensions such that it can not be placed in operating configuration in the launcher fairing to orbit the satellite. Therefore, a radar antenna is generally formed by a structure known deployable. Such a structure comprises a plurality of antenna panels are hinged together so as to take a storage configuration for the start, in which the panels are stacked on each other, and an operating configuration after the putting into orbit of satellite, wherein the antenna panels are deployed and form a plane panel. More specifically, in the storage configuration, the antenna panels are stacked on both sides of the body of the satellite on two opposite faces. The panels are hinged from a central antenna panel fixed on a third face of the box. Satellites also require a power source, usually supplied from solar generators with solar panels. The missions are more "expensive" energy, they require solar panels increasingly large. An increase in the size of solar panels, however, poses problems both for the storage configuration for the operating configuration of the radar antenna. Indeed, the satellite box forms overall a parallelepiped whose two faces on which are stacked antenna panels in the storage configuration have a greater width than the third face to which is fixed the central antenna panel. Consequently, the volume available for the storage of solar panels at the face opposite the third face is relatively limited. In operating configuration, the solar panels are deployed and deported from the body of the satellite. Therefore, the antenna panels and solar panels may be of mutually the shade. The solar panels are likely to disrupt the operation of the radar antenna.

An object of the invention is to obviate the above drawbacks by allowing a satellite to include an antenna formed by a deployable structure and relatively large solar panels without the antenna and solar panels will make shade mutually. To this end, the invention relates to a deployable structure that can be fitted to a satellite, comprising:<ul><li>■ a set of antenna panels, each having a substantially rectangular effective area, the antenna panels being butted to each other by first parallel sides,</li><li>■ at least one photovoltaic solar panel, each photovoltaic solar panel being abutted to an antenna panel by a second side of said antenna panel, perpendicular to the first sides,</li><li>■ first hinge systems, each said hinge system for pivoting an antenna panel with respect to an adjacent antenna panel according to an axis substantially parallel to the first sides of said antenna panels,</li><li>■ a second hinge system for each photovoltaic solar panel, each of said articulation systems to rotate a photovoltaic solar panel relative to the antenna panel to which it is butted in a substantially parallel axis to the second side of said panel of antenna.</li></ul>

The invention has the particular advantage that it can predict the same stacking systems, deployment and articulation for antenna panels and solar panels.

The invention will be better understood and other advantages will appear on reading the following description, made with reference to the accompanying drawings wherein: <ul><li>the <figref idrefs="f0001">1A and 1B figures</figref> show schematically, in a perspective view and in a cross-sectional view, respectively, a launcher cap which is installed in a satellite comprising a radar antenna in a storage configuration;</li><li>the <figref idrefs="f0002">2</figref> schematically shows, in a perspective view of the satellite <figref idrefs="f0001">Figures 1 A and 1 B</figref> equipped with the radar antenna in an operating configuration;</li><li>the <figref idrefs="f0003">3A, 3B and 3C</figref> show schematically in a front view, in a longitudinal sectional view, and a cross-sectional view, respectively, the starter cap which is installed in a satellite comprising an exemplary deployable structure according to the invention in the configuration storage;</li><li>the <figref idrefs="f0004">4</figref> schematically shows, in a perspective view, the satellite including the deployable structure <figref idrefs="f0003">3A, 3B and 3C</figref> in the operating configuration;</li><li>the <figref idrefs="f0005">5A, 5B, 5C and 5D</figref> schematically an example of an articulation system for connecting two panels of the deployable structure therebetween;</li><li>the <figref idrefs="f0005">6A, 6B</figref>, <figref idrefs="f0006">6C, 6D and 6E</figref> illustrate an example of kinematic deployment of the deployable structure <figref idrefs="f0003">3A, 3B, 3C</figref> and <figref idrefs="f0004">4</figref> ;</li><li>the <figref idrefs="f0007">7</figref> shows schematically, in a perspective view, a satellite comprising another exemplary deployable structure according to the invention in the operating configuration.</li></ul>

The <figref idrefs="f0001">1A and 1B figures</figref> show schematically, in a perspective view and in a cross-sectional view, respectively, a launcher cap which is installed in a satellite comprising a radar antenna in a storage configuration. The starter cover 10 comprises a hollow cylindrical portion 11 and a conical portion 12. A satellite 13 is installed in the hollow cylindrical portion 11. The satellite 13 comprises a box 14 of generally parallelepiped form. The box 14 has four outer side faces 14A, 14B, 14C and 14D adapted to receive deployable structures. In this case, the satellite 13 is equipped with a deployable antenna 15 formed of a set of antenna panels 151 to 157 are hinged together by hinge systems 16. The antenna panels have a 151-157 substantially rectangular shape. A first antenna panel 154 is fixed on the face 14A of the body 14. The face 14A and 14C opposite face have a smaller width than 14B and 14D faces. The antenna panel 154 or the satellite 13 is directly connected to two other antenna panels 153 and 155 by hinge system 16. The antenna panels 153 and 155 are respectively connected to an antenna panel 152 and to an antenna panel 156, by hinge systems 16. the antenna panels 152 and 156 are themselves connected to antenna panels 151 and 157 by hinge system 16. in the configuration storage shown in<figref idrefs="f0001">1A and 1B figures</figref>, Antenna panels 151 to 153 on the one hand, and 155 to 157 on the other, are stacked parallel to each other. 151-153 the antenna panels are folded relative to the antenna panel 154 so that the antenna panel 153 bears on the 14D face of the body 14. The antenna panels 155-157 are folded relative to the antenna panel 154 so that the antenna panel 155 comes to bear against the face 14B of the body 14. the satellite 13 is also equipped with a solar generator comprising a photovoltaic solar panel 17 connected 14C to face with a stop arm 18. 151-157 antenna panels must be able to form a relatively large antenna surface. For this reason, they are stacked on the faces 14B and 14D having the greater width. The volume available for the solar panel 17 is reduced. The solar panel 17 can therefore hardly have large dimensions.

The <figref idrefs="f0002">2</figref> shows schematically, in a perspective view the satellite 13 equipped with deployable antenna 15 in the operating configuration, also called operational configuration. In this configuration, the antenna panel 154 is abutted by two opposite sides the antenna panels 153 and 155. Similarly, the antenna panels 151 and 152 on the one hand, and 156 and 157 on the other hand , are abutted in series to the antenna panels 153 and 155, respectively, so as to form a generally rectangular effective area substantially flat and continuous. The solar panel 17 is offset from the box 14 by the stop arm 18. In some configurations of the satellite 13 on the orientation of the antenna 15 and the solar panel 17, and the relative position of the sun, the solar panel 17 is likely to screen between the sun and the antenna 15. the operation of the antenna 15 is then degraded due to thermoelastic deformations it undergoes.

The <figref idrefs="f0003">3A, 3B and 3C</figref> show schematically in a front view, in a longitudinal sectional view, and a cross-sectional view, respectively, a launcher cap which is installed in a satellite comprising an exemplary deployable structure according to the invention in the configuration storage. The satellite 31 according to the invention differs essentially from the satellite 13 described with reference to<figref idrefs="f0001">1A, 1B</figref> and <figref idrefs="f0002">2</figref>In that it is equipped with a deployable structure 32 having both the antenna panels 151 to 157 forming the expandable antenna 15, and solar panels 331 to 334. The deployable antenna 15 on the satellite 31 is substantially identical to that on the satellite 13. the first antenna panel 154 is fixed on the face 14A of the body 14. the antenna panels 151 to 153 on the one hand, and 155 to 157 on the other, are connected in series on either side of the antenna 154 by the hinge panel 16. These systems 151-153 and 155-157 of antenna panels can be attached either to the body 14 of the satellite 13, either antenna panel 154. in the storage configuration shown in <figref idrefs="f0003">3A, 3B and 3C</figref>, The antenna panels 151-153 on the one hand, and 155-157 on the other hand, are stacked parallel to each other. 151-153 the antenna panels are folded relative to the antenna panel 154 so that the antenna panel 153 abuts on a 14D face of the body 14. The antenna panels 155-157 are folded relative to the antenna panel 154 so that the antenna panel 155 comes to bear against the face 14B of the body 14. the expandable structure 32 further comprises four solar panels 331 to 334. the solar panels 331 and 332 are connected to the antenna panel 151 by hinge systems 19. the solar panels 333 and 334 are connected to the antenna panel 157 by hinge systems 19. in the storage configuration shown in<figref idrefs="f0003">3A, 3B and 3C</figref>, The antenna panels 151-153 and solar panels 331 and 332 are stacked parallel to each other, the antenna panel 153 being supported on the 14D face of the body 14, and the solar panel 332 forming the last outer layer of the stack of panels. The antenna panels 155-157 and solar panels 333 and 334 are stacked parallel to each other, the antenna panel 155 bearing against the face 14B of the body 14, and the solar panel 334 forming the last outer layer of the stack of panels. This position allows them opening in the early stages of the orbiting satellite 13, allowing a satellite's power supply. This partial opening ensures the survival of the spacecraft and facilitates its control during its positioning operations due to reduced dimensions structure deployed. The width of the solar panels 331-334 may be slightly less than that of the antenna panels 151-157 so as to conform to the available space in the hollow cylindrical portion 11 of the cap 10 of the launcher.

The <figref idrefs="f0004">4</figref> shows schematically, in a perspective view the satellite 31 equipped with the deployable structure 32 in the operating configuration. In this configuration, the antenna panels 151-157 are abutted in series by their sides having a greater width so as to form a generally rectangular effective area 15A substantially flat and continuous. Solar panels 331 and 332 are deployed on either side of the antenna panel 151. The antenna panel 151 abuts by one of its sides of lesser width to one side of smaller width the solar panel 331 and the side opposite to one side of smallest width of the solar panel 332. Similarly, the solar panels 333 and 334 are deployed on either side of the antenna panel 157. the antenna panel 157 abuts by one of its sides of lesser width to one side of smallest width of the solar panel 333 and the side opposite to one side of smallest width of the solar panel 334. solar panels 331-334 are not necessarily made in the same plane as the plane of the working surface 15A of the deployable antenna 15. They can each form an angle with the floor space of the antenna panels to move towards solar radiation.

To go from the storage configuration to the operational configuration, the deployable structure 32 comprises articulation systems 16 and 19. These articulation systems 16 and 19 may be structurally identical to the connections between antenna panels 151- 157 and the connections between antenna panels 151, 157 and 331-334 solar panels. They can also be different, as is generally the case when a deployable structure is capable of being deployed in two orthogonal directions. An example of articulation 19 is especially in patent<patcit id="pcit0001" dnum="FR2635077"><text>FR 2635077</text></patcit>. Each hinge system 16 or 19 must be able to rotate one panel relative to another according to an axis substantially parallel to the working surfaces of these panels. The rotational axes of the articulation systems 16 between the various antenna panels 151-157 are substantially mutually parallel and alongside greater width of the antenna panels 151-157. The rotational axes of the articulation systems 19 between an antenna panel 151, 157 and 331-334 solar panel are substantially parallel to the sides of smaller width of said panels.

The <figref idrefs="f0005">5A to 5D</figref> represent an example of an articulation system for connecting two panels together. Considering for example the hinge system 16 between the antenna panel 151 and the antenna panel 152. The<figref idrefs="f0005">5A</figref> represents the joint system in a position corresponding to the storage configuration. The<figref idrefs="f0005">Figures 5B and 5C</figref> represent the linkage system 16 in positions where the antenna panels 151 and 152 are being deployed relative to another. The<figref idrefs="f0005">5D</figref> represents the linkage system 16 in a position corresponding to the operating configuration, the antenna panels 151 and 152 being deployed. The hinge system 16 comprises a first part 161 on which the antenna panel 151 is intended to be mounted, a second part 162 on which the antenna panel 152 is intended to be mounted, and a third piece 163. The second part 162 is pivotally connected relative to the first member 161 along a first axis 164. the third piece 163 is pivotally connected relative to the first member 161 along a second axis 165, substantially parallel to the first axis 164. the second part 162 comprises a stop 166 adapted to bear against a bearing surface 167 of the first part 161 in the position corresponding to the operating configuration, as illustrated in<figref idrefs="f0005">5D</figref>. The stop 166 and the bearing surface 167 can limit the rotational movement between the first and second parts 161, 162 once the position corresponding to the achievement of operating configuration. The third part 163 includes a check 168 capable of coming into abutment on a bearing surface 169 of the second piece 162 in the position corresponding to the operating configuration. The backstop 168 and the bearing surface 169 sufficient to prevent rotational movement between the first and second parts 161, 162 to the storage position after reaching the extended position. The hinge systems 16 and provide both a rotary guide function and a lock function of the panels. They can also ensure a motorizing function of driving the panels of the storage configuration to the operating configuration. The drive torque is provided by eg a spiral spring. The deployment of the panels can be triggered by a pyrotechnic device known to the prior art.

The <figref idrefs="f0005 f0006">6A-6E</figref> illustrate an example of deployment kinematics of the expandable structure shown in <figref idrefs="f0003">3A, 3B, 3C</figref> and <figref idrefs="f0004">4</figref>. The<figref idrefs="f0005">6A</figref> represents the satellite 31 in a first stage of deployment of the expandable structure 32. In this step, the antenna panels 151 and 157 are deployed. They are rotated with respect to the antenna panels 152 and 156, respectively, along two axes substantially parallel to the sides of greater width of the antenna panels 152 and 156. The solar panels 331-334 are connected to the panels antenna 151 and 157, they are also rotated along these axes. The antenna panels 152, 153, 155 and 156 are stacked counters 14B and 14D faces of the body 14 of the satellite 31. The<figref idrefs="f0005">6B</figref> represents the satellite 31 in a second step of deployment of the deployable structure 32. This second stage begins when the antenna panels 151 and 157 have reached their position corresponding to the operation of the antenna configuration 15. The antenna panels 151 and 157 then form a flat surface with the antenna panel 154. In the second step, the solar panels 332 and 334 are deployed. They are rotated with respect to the antenna panels 151 and 157, respectively, along two axes substantially parallel to the sides of smaller width of the antenna panels 151 and 157. The antenna panels 152, 153, 155 and 156 are stacked against the crate 14. the solar panels 332 and 334 are deployed until the desired position in the operating configuration. Solar panels 331 and 333 are then deployed in a third step. The opening of the solar panels 331 and 333 can be controlled by the locking of the joint 16 systems allowing the opening of the antenna panels 151 and 157. The solar panels 331 and 333 are rotated with respect to the panels antenna 151 and 157, respectively, along two axes substantially parallel to the sides of smaller width of the antenna panels 151 and 157. the solar panels 331 and 333 are made until the desired position in the operating configuration. This position is shown on the<figref idrefs="f0006">6C</figref>. The<figref idrefs="f0006">6D</figref> represents the satellite 31 in a fourth stage the deployment of the deployable structure 32. In this step, not yet deployed antenna panels are. In this case, the antenna panels 152, 153, 155 and 156 are rotated simultaneously with respect to the antenna panels 151, 154 and 157 along substantially parallel axes alongside larger width of these panels antenna. The antenna panels 152 and 153 on the one hand, and 155 and 156 on the other, are rotated relative to each other along two axes substantially parallel to the sides of greater width of the panels . The antenna panels 152, 153, 155 and 156 are made until they reach their position corresponding to the operational configuration, shown in<figref idrefs="f0006">6E</figref>.

The deployment kinematics of the deployable structure 32 may differ from that described with reference to <figref idrefs="f0005 f0006">6A-6E</figref>. In this case, the deployment of 152-153 and 155-157 antenna panels and solar panels 331-334 may be initiated before the end of the deployment of antenna panels 151 and 157.

The deployable structure 32 may comprise a larger number of solar panels than that shown in <figref idrefs="f0003">3A, 3B, 3C</figref> and <figref idrefs="f0004">4</figref>. The<figref idrefs="f0007">7</figref> shows schematically, in a perspective view, a satellite 71 with a sample 72 deployable structure according to the invention having twelve solar panels in the operating configuration. Relative to the deployable structure 32 of the satellite 31, the expandable structure 72 has an additional solar panel of either side of each solar panel 331-334. In other words, each solar panel comprises a main solar panel connected to one of the antenna panels 151 or 157, and secondary solar panels 341-348 connected to this main solar panel 331-334. The main solar panel 331 is abutted to a first secondary solar panel 341 by one of its sides of larger size, and a second secondary solar panel 342 by its opposite side. Solar panels 331, 341 and 342 thus form a rectangular helpful substantially flat surface. The solar panel 342 is abutted by its side of smaller width to the antenna panel 152, without being mechanically connected to this panel. Similarly, the main solar panels 332, 333 and 334 are each edge at a first secondary solar panel 343, 345 and 347, respectively, and a second secondary solar panel 344, 346 and 348, respectively, by their sides more large. Solar panels 331-334 and 341-348 may be interconnected by the same joints systems connecting the antenna panels 151-157 between themselves and the antenna panels 151, 157 to the solar panels key 331-334. Each hinge system allows you to rotate a secondary solar panel 341-348 compared to a main solar panel 331-334 along an axis parallel to the sides of larger solar panels. An advantage of articulating solar panels together rather than individually articulate with an antenna panel is that the orientation of all of these panels can be performed by a single hinge arrangement, namely between the main solar panel 331, 332, 333 or 334 and the antenna panel 151 or 157. articulation systems between solar panels can be much simpler since they must be configured only for one stable position, namely that corresponding to the operating configuration in which the panels are in the same plane. In the storage configuration, the 341-348 side solar panels can be folded parallel to the main solar panel 331-334 which they are connected. The deployment of the deployable structure 72 then comprises an additional step of driving the second rotating solar panels 341-348 in relation to solar 331-334 main panels along substantially parallel axes alongside larger width of these panels. The opening of the solar panels 341-348 may be controlled by the locking of the articulation systems 19 for opening of main solar panels 331-334. Solar 331-334 main and secondary panels 341-348 may also be arranged in the storage configuration so as to supply electric energy only deploying the antenna panels 151 and 157. Of course, the deployable structure according the invention may comprise any number of solar panels connected to any antenna panel, or any solar panel.