Flexible radiative fin for a spacecraft
View Patent ↗A radiative fin for a spacecraft is disclosed having an end fitting of heat conductive material, configured to be mounted on the spacecraft, a flexible radiative laminate, connected to the end fitting at one end and having an opposite free end, at least one pyrolytic graphite sheet, and at least one heat emission layer in contact with the pyrolythic graphite sheet on at least part of the surface of the pyrolythic graphite sheet, and a flexible rod, extending from the end fitting along at least part of a side of the flexible radiative laminate and being affixed to the latter. The flexible rod is adapted to occupy a folded position and a deployed position and to exert, while in the folded position, a deployment torque adapted to bring the flexible rod back to the deployed position.
1. A radiative fin for a spacecraft (S), comprising:
an end fitting of heat conductive material, adapted to be mounted on the spacecraft (S),
a flexible radiative laminate, connected to the end fitting at one end and having an opposite free end, and comprising:
at least one pyrolytic graphite sheet, and
at least one heat emission layer in contact with the at least one pyrolytic graphite sheet on at least part of the surface of the at least one pyrolytic graphite sheet, and
a flexible rod, extending from the end fitting along at least part of a side of the flexible radiative laminate and being affixed to the latter, wherein the flexible rod is adapted to occupy a folded position and a deployed position and to exert, while in the folded position, a deployment torque adapted to bring the flexible rod back to the deployed position.
2. A radiative fin according to claim 1 , wherein the flexible rod is a pinned hinge.
3. A radiative fin according to claim 1 , wherein the flexible rod is a pinless hinge, being either a strip comprising a portion of reduced width dimensioned to exhibit an elastic behavior in the folded and deployed positions, or a Carpentier joint.
4. A radiative fin according to claim 1 , further comprising a stiffening rod extending along the side of the flexible radiative laminate from a free end of the flexible rod.
5. A radiative fin according to claim 1 , further comprising a stiffening rod extending along the side of the flexible radiative laminate opposite the side where the flexible rod extends, from a distance of the end fitting equal to the distance between the free end of the flexible rod and the end fitting, to the free end of the radiative laminate.
6. A radiative fin according to claim 1 , wherein, in the deployed position, an angle between the ends of the flexible rod is of 180° and, in the folded position, the angle between the ends is less than 30°, and the radiative fin further comprises an end of the flexible rod preventing the flexible rod from reaching a position beyond the deployed position when it is released from the folded position.
7. A radiative fin according to claim 1 , wherein the flexible radiative laminate comprises a portion extending from the free end of the flexible rod to the free end of the radiative laminate, said portion comprising a plurality of pyrolytic graphite sheets, each pyrolytic graphite sheet being bonded to a next pyrolytic graphite sheet by a layer of adhesive material.
8. A radiative fin according to claim 1 , wherein the flexible radiative laminate comprises a portion extending from the end fitting to the free end of the flexible rod, said portion being devoid of heat conductive layer and comprising a plurality of unbonded pyrolytic graphic sheets.
9. A radiative fin according to claim 1 , further comprising a stiffening rod extending over the flexible radiative laminate from a free end of the flexible rod, and parallel to the end fitting.
10. A radiative find according to claim 1 , further comprising a stiffening rod extending along at least a width of the free end of the radiative laminate.
11. A radiative fin according to claim 1 , further comprising a clamping means arranged at the free end of the radiative laminate.
12. A radiative fin according to claim 1 , wherein the heat emission layer comprises a protective layer made of one of polyimide film, titanium film, carbon fiber reinforced plastic film, and a radiative coating chosen among white paint, black paint, second surface mirror foil, and optical solar reflector tiles.
13. A radiative fin according to claim 1 , wherein the end fitting is made of aluminum.
14. A radiative fin according to claim 1 , wherein, in the folded position, the angle between the ends of the flexible rod is equal to 0°.
15. A spacecraft (S) comprising at least one radiative fin according to claim 1 .
16. A spacecraft (S) according to claim 15 further comprising at least one solar array wing (G) and a deployment mechanism adapted to bring the solar array wing (G) from a stowed position to a deployed position,
wherein the radiative fin is maintained, in the folded position, between the solar array wing (G) and a wall of the spacecraft by the solar array wing (G), and wherein the deployment of the solar array wing (G) allows the radiative laminate of the fin to reach to the deployed position.