Satellite control system using electrically controllable variable reflection glass panels

Patent metadata

Field	Value
Publication number	US-10647450-B2
Application number	US-201615074786-A
Country	US
Kind code	B2
Filing date	Mar 18, 2016
Priority date	Mar 18, 2016
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A method and apparatus for the control of the attitude of earth orbiting satellites and the orbit and attitude control of a novel gravitational wave detection satellite configuration located near the sun-earth Lagrangian points L3, L4 and L5, utilizing the control of solar radiation pressure by the use of electrically controllable variable reflection glass panels to provide the torques and forces needed.

First claim

What is claimed is:

1. A method of controlling a satellite having a satellite body, comprising:
accepting an error signal; and
varying a reflectivity of at least one control panel coupled to the satellite body and at least partially facing the sun according to the error signal to control the satellite in at least one of orbit and attitude;
wherein the control panel comprises a glass panel having an electrically controllable variable reflection, wherein the glass panel comprises:
a first outer transparent layer located on a side of the control panel facing the sun;
a second outer transparent layer, having a reflective film located on a second transparent layer outer surface opposing the first transparent layer; and
a middle layer, located between the first outer transparent and the second outer transparent layer, the middle layer having an electrically controllable transparency.

2. The method of claim 1 , wherein:
the at least one control panel comprises a plurality of control panels at least partially facing the sun, comprising:
a first control panel located on a first side of a center of mass of the satellite; and
a second control panel located on a second side of the center of mass of the satellite, diametrically opposing the first side of the center of mass of the satellite;

varying the reflectivity of the at least one control panel coupled to the satellite body according to the error signal comprises:
varying the reflectivity of each of the first control panel and the second control panel according to the error signal.

3. The method of claim 2 , wherein:
the satellite comprises a first solar panel and a second solar panel, each coupled to and extending from the satellite body;
the first control panel is coupled to the first solar panel; and
the second control panel is coupled to the second solar panel.

4. The method of claim 1 , wherein:
the at least one control panel comprises a plurality of pairs of control panels at least partially facing the sun, and located about a periphery of the satellite and symmetrically about a sunline between the satellite and the sun;
wherein each of the plurality of pairs of control panels comprises a first control panel having a first control panel surface normal at an angle θ from a sunline between the satellite and the sun and a second control panel having a second control panel surface normal at an angle −θfrom the sunline between the satellite and the sun;
varying the reflectivity of the at least one control panel coupled to the satellite body according to the error signal comprises:
varying a reflectivity of the plurality of control panels according to the error signal.

5. The method of claim 4 , wherein:
the plurality of pairs of control panels comprises:
a first pair of control panels, located on a first side of the center of mass of the satellite;
a second pair of control panels, located on a second side of the center of mass of the satellite diametrically opposing the first pair of control panels;
a third pair of control panels, located on a third side of the center of mass of the satellite; and
a fourth pair of control panels, located on a fourth side of the center of mass of the satellite diametrically opposing the third pair of control panels.

6. The method of claim 5 , wherein the satellite is located near a Lagrangian point.

7. The method of claim 6 , wherein:
the reflectivity of the at least one control panel is varied from a midpoint of control panel reflectivity; and
the satellite is located away from the Lagrangian point towards the sun to a location at which, with the control panels at a midpoint of reflectivity, the gravitational and centrifugal forces balance the total solar radiation force on the satellite.

8. The method of claim 1 , wherein:
the middle layer comprises liquid crystal droplets embedded in a polymer and electrically coupled to transparent electrodes; and
varying the reflectivity of the at least one control panel coupled to the satellite body according to the error signal comprises:
varying a voltage applied to the electrodes according to the error signal.

9. The method of claim 8 , wherein varying the voltage applied to the electrodes according to the error signal comprises:
determining the applied voltage according to a predetermined lookup table relating light reflected by the control panel and the voltage applied to the electrodes.

10. The method of claim 1 , wherein the reflectivity is continuously variable in time and continuously variable in magnitude.

11. The method of claim 1 , wherein:
the satellite body is cylindrically shaped, and comprises:
a substantially cylindrical surface having an upper portion and a lower portion;

the at least one control panel comprises:
a first control panel located on the upper portion of the satellite body; and
a second control panel located on a lower portion of the satellite body;

varying the reflectivity of the at least one control panel coupled to the satellite body according to the error signal comprises:
varying a reflectivity of each of the first control panel and the second control panel according to the error signal.

12. The method of claim 11 , wherein the first control panel and the second control panel substantially conform to the cylindrical surface.

13. The method of claim 1 , wherein the reflectivity of the at least one control panel is varied from a midpoint of control panel reflectivity.

Assignees

• Boeing Co

Inventors

• Rosen Harold A

Classifications

• B64G1/242 Primary

  Orbits and trajectories · CPC title

• B64G1/363

  using sun sensors · CPC title

• B64G1/1007

  Communications satellites · CPC title

• B64G1/407

  Solar sailing · CPC title

• B64G1/105

  Space science · CPC title