Device for monitoring the attitude of a satellite, and method for controlling a satellite provided with said device

Patent metadata

Field	Value
Publication number	US-9227740-B2
Application number	US-201213980667-A
Country	US
Kind code	B2
Filing date	Jan 25, 2012
Priority date	Jan 25, 2011
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A device for controlling the attitude of a satellite exploiting solar pressure, includes at least two solar generators destined to be arranged on either side of a central body of the satellite and each having one face to be exposed to the Sun, referred to as “front face”, the device also including at least three surfaces whose optical properties can be commanded. The surfaces whose optical properties can be commanded are arranged on flaps connected to solar generators, each flap being fixed with respect to the solar generator to which it is connected, and such that, in the operating position, at least two of the surfaces are not parallel when the front faces of the solar generators are optimally oriented with respect to the Sun. The device further includes a module for commanding the optical properties of each surface whose optical properties can be commanded.

First claim

The invention claimed is:

1. Device for controlling the attitude of a satellite exploiting solar pressure, comprising at least two solar generators arranged on either side of a central body of the satellite, extending along a rotation axis of said solar generators, each solar generator having one face to be exposed to the Sun, referred to as “front face”, said device further comprising at least three surfaces whose optical properties can be commanded, wherein said surfaces whose optical properties can be commanded are arranged:
on flaps connected to solar generators, each flap being fixed with respect to the solar generator to which said flap is connected, and
such that at least two of said surfaces whose optical properties can be commanded are not parallel when the front faces of the solar generators are parallel,
wherein said device comprises a command module adapted to command separately the optical properties of each surface whose optical properties can be commanded, said command module being configured to command said surfaces whose optical properties can be commanded so as to create torques around three independent axes without de-pointing the solar generators with respect to the Sun.

2. Device according to claim 1 , wherein it comprises at least four flaps having substantially flat surfaces whose optical properties can be commanded, each of these surfaces having an inclination with respect to the front face of the solar generator to which said surface is connected.

3. Device according to claim 2 , wherein the absolute value of the inclination, between the surface whose optical properties can be commanded of each flap and the front face of the solar generator to which said flap is connected, is between 5° and 20°.

4. Device according to claim 3 , wherein the flaps of one pair of flaps of a solar generator are arranged so as to have substantially the same inclination with respect to said solar generator's front face.

5. Device according to claim 1 , wherein at least one surface whose optical properties can be commanded comprises an electrochromic material, preferably an electrochromic material that can take at least two optical states.

6. Device according to claim 5 , wherein it comprises at least four flaps having substantially flat surfaces whose optical properties can be commanded, each of these surfaces having an inclination with respect to the front face of the solar generator to which said surface is connected.

7. Device according to claim 6 , wherein the absolute value of the inclination, between the surface whose optical properties can be commanded of each flap and the front face of the solar generator to which said flap is connected, is between 5° and 20°.

8. Device according to claim 7 , wherein the flaps of one pair of flaps of a solar generator are arranged so as to have substantially the same inclination with respect to said solar generator's front face.

9. Device according to claim 1 , wherein at least one surface whose optical properties can be commanded comprises a network of several cells whose optical properties can be commanded, the command module being adapted to command separately each cell whose optical properties can be commanded.

10. Device according to claim 1 , wherein at least one surface whose optical properties can be commanded is realized with an element having static optical properties, said element with static optical properties comprising at least two areas with different static optical properties, and with means of mechanically modifying the respective proportion of each of the at least two areas with different static optical properties in the portion of the element with static optical properties that is exposed to the Sun's rays.

11. Device according to claim 10 , wherein the element with static optical properties is a band, and wherein it comprises at least one roller whose rotation causes the scrolling of the band and the modification of the respective proportion of each of the at least two areas with different static optical properties in the portion of the band exposed to the Sun's rays.

12. Device according to claim 10 , wherein it comprises at least four flaps having substantially flat surfaces whose optical properties can be commanded, each of these surfaces having an inclination with respect to the front face of the solar generator to which said surface is connected.

13. Device according to claim 12 , wherein the absolute value of the inclination, between the surface whose optical properties can be commanded of each flap and the front face of the solar generator to which said flap is connected, is between 5° and 20°.

14. Device according to claim 13 , wherein the flaps of one pair of flaps of a solar generator are arranged so as to have substantially the same inclination with respect to said solar generator's front face.

15. Satellite comprising an attitude control device according to claim 1 .

16. Method for commanding a satellite comprising an attitude control device according to claim 1 , comprising the following steps:
determining an optimal orientation of the front faces of the solar generators with respect to the Sun,
orienting the front faces of the solar generators according to the optimal orientation,
determining a torque to be formed around three independent axes for controlling the attitude of the satellite,
commanding the optical properties of the surfaces whose optical properties can be commanded so as to form said attitude control torques while keeping the front faces of the solar generators in their optimal orientation.

17. Method according to claim 16 , wherein the optical properties of the surfaces are modulated over time so as to obtain an optical state corresponding to a weighted mean of the optical states available for said surfaces.

Assignees

• Lagadec Kristen
• Chabot Thomas
• Airbus Defence & Space Sas

Inventors

• Lagadec Kristen
• Chabot Thomas

Classifications

• B64G1/407

  Solar sailing · CPC title

• B64G1/24

  Guiding or controlling apparatus, e.g. for attitude control · CPC title

• B64G1/363 Primary

  using sun sensors · CPC title

• B64G1/244 Primary

  Spacecraft control systems · CPC title