System and method for observing a satellite using a satellite in retrograde orbit

• US 20080081556A1
• Filed: 10/03/2006
• Published: 04/03/2008
• Est. Priority Date: 10/03/2006
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Robinson, Ian S.
• Granted Patent: US 8,090,312 B2
• Time in Patent Office: Days
• US Class Current: 455/12.1
• CPC Class Codes: H04B 7/18519 Operations control, administration or maintenance

Abstract

A satellite and an arrangement for placing the satellite in a retrograde orbit, i.e. inclined at approximately 180° to the equator. Multiple satellites may be used and the orbits thereof may be circular or elliptical. The invention is well-suited for an illustrative satellite inspection application. In this embodiment, the system includes one or more satellites; means disposed on each satellite for receiving electromagnetic energy from objects (e.g. satellites) within a field-of-view thereof; and an arrangement for placing the inspection satellites in a retrograde orbit. The satellites may be equally spaced in a single orbit or disposed in equally spaced orbits. The satellites may include a variety of instruments including radar, infrared, visible, etc. In a radar implementation, the satellite may include a bistatic or (with a transmitter) monostatic radar system. In the bistatic case, the signal may be transmitted from a ground-based or space based platform.

Claims

1. A system comprising:

a satellite and

means for placing said satellite in a retrograde orbit.

2. The invention of claim 1 wherein said orbit is circular.

3. The invention of claim 2 wherein said orbit is inclined at approximately 180°

to the equator.

4. The invention of claim 3 wherein said orbit is at an altitude of approximately 35,800 kilometers.

5. The invention of claim 3 wherein said orbit is at an altitude of approximately 35,300 kilometers.

6. The invention of claim 1 wherein said orbit is eccentric.

7. The invention of claim 6 wherein said orbit is elliptical.

8. The invention of claim 1 wherein said orbit is inclined from the equator.

9. The invention of claim 8 wherein said orbit is inclined up to 9°

from the equator.

10. The invention of claim 1 further including N satellites disposed in said orbit, where N is an integer greater than or equal to one.

11. The invention of claim 10 wherein said satellites are disposed in equally spaced orbital planes.

12. The invention of claim 10 wherein said satellites are equally spaced in a single orbital plane.

13. The invention of claim 1 wherein said orbit has an apogee height of 35,300 kilometers.

14. The invention of claim 1 wherein said orbit has an apogee height of 35,800 kilometers.

15. A satellite inspection system comprising:

a satellite;

means disposed on said satellite for receiving electromagnetic energy from objects within a field-of-view thereof; and

means for placing said satellite in a retrograde orbit.

16. The invention of claim 15 wherein said orbit is circular.

17. The invention of claim 16 wherein said orbit is inclined at approximately 180°

to the equator.

18. The invention of claim 17 wherein said orbit is at an altitude of approximately 35,800 kilometers.

19. The invention of claim 17 wherein said orbit is at an altitude of approximately 35,300 kilometers.

20. The invention of claim 15 wherein said orbit is eccentric.

21. The invention of claim 20 wherein said orbit is elliptical.

22. The invention of claim 15 wherein said orbit is inclined from the equator.

23. The invention of claim 22 wherein said orbit is inclined up to 9°

from the equator.

24. The invention of claim 15 further including N satellites disposed in said orbit, where N is an integer greater than or equal to one.

25. The invention of claim 24 wherein said satellites are equally spaced.

26. The invention of claim 15 wherein said means for receiving electromagnetic energy from objects within a field-of-view thereof includes a radar receiver.

27. The invention of claim 26 wherein said receiver is an X-band receiver.

28. The invention of claim 26 wherein said receiver is bistatic.

29. The invention of claim 15 wherein said means for receiving electromagnetic energy includes a receiver adapted to detect visible and/or infrared energy.

30. The invention of claim 15 wherein said means for receiving electromagnetic energy includes a lens.

31. The invention of claim 30 wherein said lens is disposed in a telescope.

32. The invention of claim 30 wherein said lens is disposed in a camera.

33. The invention of claim 15 wherein said object is a second satellite.

34. The invention of claim 33 wherein said second satellite is disposed in a geosynchronous orbit.

35. The invention of claim 34 wherein said second satellite is disposed in a geostationary orbit.

36. A method comprising the steps of:

launching a satellite and

placing said satellite in a retrograde orbit.

37. A object observation and inspection method comprising the steps of:

providing a satellite;

providing means on said satellite for receiving electromagnetic energy from objects within a field-of-view thereof; and

placing said satellite in a retrograde orbit.