Asymmetric open rosette constellations

• US 6,050,525 A
• Filed: 04/28/1998
• Issued: 04/18/2000
• Est. Priority Date: 04/29/1997
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Drake, John Howard
• Primary Examiner(s): Poon, Peter M.
• Assistant Examiner(s): DINH, TIEN QUANG
• Application Number:
  US09/069,090
• Time in Patent Office: 721 Days
• Field of Search: 244/158 R, 701/226, 455/12.1, 455/13.2
• US Class Current: 244/158.4
• CPC Class Codes: B64G 1/1007 Communications satellites
• CPC Class Codes: B64G 1/1085 Swarms and constellations
• CPC Class Codes: B64G 1/242 Orbits and trajectories
• CPC Class Codes: H04B 7/195 Non-synchronous stations

Abstract

An asymmetric open rosette constellation has multiple inclined orbit planes distributed around 360° with the satellites asymmetrically spaced in the orbit planes. The satellites populate only a portion of each orbital plane so as to leave an open space in each orbital plane. The open architecture can readily accommodate spare satellites in a useful manner.

Claims

1. A method of deploying a constellation of satellites in an asymmetric open rosette architecture orbiting about the earth by using multiple inclined orbital planes of satellites with the satellites in each plane asymmetrically spaced in a cluster so as to leave an open space or gap between a trailing satellite and a leading satellite in each of the orbital planes of the constellation, said method comprising,

placing a first cluster of satellites in a first asymmetrical spacing in a first orbital plane inclined at a first angle with respect to a reference circle extending about the earth,

said first cluster having a leading satellite and a trailing satellite,

said first cluster of satellites populating only a portion of the orbital plane so as to leave a first open space or gap between the trailing satellite and the leading satellite in said first inclined orbital plane,

placing additional clusters of satellites in asymmetrical spacings in additional inclined orbital planes and wherein each additional inclined orbital plane has the same inclination angle as said first inclined orbital plane, has the same cluster of satellites as in said first cluster, has the same asymmetrical spacing as said first asymmetrical spacing, and has the same open space as said first open space,

said first and additional orbital planes being distributed about said reference circle,

phasing all of the satellites so that corresponding satellites in each orbital plane all reside on a single wave form which rotates around the earth on an axis normal to the plane of reference for the inclination angle of the planes, and wherein the wave form has at least two cycles, and wherein there is a leading wave form containing a leading satellite in each orbital plane and a trailing wave form containing a trailing satellite in each orbital plane.

2. The invention defined in claim 1 wherein the number of satellites in the partially filled orbit planes and the space between the satellites in each orbital plane and the relative phasing of each orbital plane are sufficient to fill the space between the leading and trailing wave forms so that the entire earth can be covered in single layers of satellite coverage patterns at least up to some desired latitude from said reference circle.

3. The invention defined in claim 1 wherein the single wave form is wave form having two cycles.

4. The invention defined in claim 1 including deploying at least one extra satellite in each orbit plane.

5. The invention defined in claim 1 including deploying extra satellites in a parking orbit about the earth.

6. The invention defined in claim 5 including repositioning satellites from the parking orbit to replace certain satellites in certain orbit planes or to change the spacings of the satellites in all of the orbit planes.

7. The invention defined in claim 1 including adding satellites to the orbit planes to fully populate the orbit planes and to provide double coverage for stereo.

8. The invention defined in claim 1 including deleting certain satellites in certain orbit planes to produce a hexagon configuration with an open center between related satellites in three related, adjacent wave forms.

9. The invention defined in claim 1 wherein a length of said first cluster of satellites is more than 180°

measured from the leading satellite to the trailing satellite in the cluster.

10. The invention defined in claim 1 wherein a length of said first cluster of satellites is less than 180°

measured from the leading satellite to the trailing satellite in the cluster.

11. The invention defined in claim 1 including phasing all of the orbit planes so that there is a shear zone between the descending waves and the ascending waves and so that the descending waves are close to, but do not overlap, the ascending waves.

12. The invention defined in claim 1 including phasing all of the orbit planes so that there is a shear zone between the descending waves and the ascending waves and so that there is a slight overlap between the leading and trailing satellites of a descending wave and of an ascending wave in the shear zone.

13. The invention defined in claim 1 including at least one ground station for communicating with one or more satellites in said constellation.

14. The invention defined in claim 1 wherein there is equal spacing between each satellite and each adjacent satellite in each first cluster except for the spacing between the leading satellite and the trailing satellite in the cluster.

15. The invention defined in claim 1 including determining the earth coverage desired and configuring the asymmetric spacing in each orbital plane which is required to obtain the desired coverage in single layers.

16. The invention defined in claim 1 wherein each satellite has an angle of coverage looking down at the earth.

17. The invention defined in claim 16 wherein each of said first clusters has eleven satellites per cluster, there are twenty one orbital planes, each of the satellites within said first clusters are spaced at equal intervals of 18.947°

, the gap between the trailing satellite and the leading satellite in each of said first clusters is 170.53°

, each satellite is in a circular orbit at an altitude of 1,360 kilometers, each orbital plane is inclined at an angle of 70°

with respect to the equator of the earth, and each adjacent orbital plane to the east is advanced 325.714°

in phase.

18. The invention defined in claim 1 wherein the satellites have an angle of coverage which looks above the horizon of the earth.

19. The invention defined in claim 18 including positioning all of the satellites in all of the clusters at an altitude with respect to the earth such that each satellite has a cone of non-coverage in its zone of above the horizon coverage because of visual impairment which can be caused by the earth and which can be caused also in at least some cases by an atmosphere layer surrounding the earth,

positioning the satellites in a first cluster in certain orbit planes such that said cones in the above the horizon coverage of each of the satellites in the cluster are at least partially covered by the coverage of one or more other satellites within said first cluster,

said trailing satellite in said first cluster being spaced so far from the leading satellite in said first cluster that (a) there is a gap in the above the horizon coverage between the trailing satellite and the leading satellite in said first cluster and (b) the gap in the above the horizon coverage must be covered by one or more other satellites either in one or more other orbit planes or in one or more other clusters in the same orbit plane,

phasing the orbits of said first clusters of satellites in said certain orbit planes so that the satellites in said clusters form waves in which at least certain ones of satellites in one or more adjacent waves produce continuous above the horizon coverage within said gap, and

whereby the orbit planes do not need to be fully populated with satellites and whereby a constellation having asymmetric arrangements of satellites in orbit planes can provide continuous above the horizon coverage at a given altitude of orbit.

20. The invention defined in claim 18 wherein the number of clusters in an orbit plane is determined by the number of lead satellites in a plane to form the desired wave structure.

21. The invention defined in claim 20 wherein the waves are three cycle waves, each orbit plane has a first cluster of three equally spaced satellites and a second cluster of three equally spaced satellites, there are five orbit planes equally spaced at 72°

intervals about the equator of the earth, each orbit plane is inclined at 55°

with respect to the equatorial plane of the earth, each orbit plane at the next 72°

interval to the east is advanced 72°

in phase compared to its adjacent orbit plane, and the orbit altitude of the satellites is 2,000 kilometers.

22. A method of positioning satellites in coherent waves in an asymmetric open rosette constellation architecture orbiting about the earth so as to provide above the horizon coverage which extends into cones of non-coverage of individual satellites in the constellation and which also extends into the gaps between trailing and leading satellites in the asymmetric clusters of satellites in orbit planes of the constellation, said method comprising,

forming a constellation of satellites having a plurality of orbit planes,

each orbit plane being inclined at the same angle with respect to a reference great circle on the earth,

each orbit plane having an asymmetric cluster of satellites in the orbit plane,

each cluster of satellites having a leading satellite and a trailing satellite in the cluster,

positioning all of the satellites in all of the clusters at an altitude with respect to the earth such that each satellite has a cone of non-coverage in its zone of above the horizon coverage because of visual impairment which can be caused by the earth and which can be caused also in at least some cases by an atmosphere layer surrounding the earth,

positioning the satellites in a first cluster in certain orbit planes such that said cones in the above the horizon coverage of each of the satellites in the cluster are at least partially covered by the coverage of one or more other satellites within said first cluster,

said trailing satellite in said first cluster being spaced so far from the leading satellite in said first cluster that (a) there is a gap in the above the horizon coverage between the trailing satellite and the leading satellite in said first cluster and (b) said gap in the above the horizon coverage must be covered by one or more other satellites either in one or more other orbit planes or in one or more other clusters in the same orbit plane,

phasing the orbits of said first clusters of satellites in said certain orbit planes so that the satellites in said clusters form waves in which at least certain ones of satellites in one or more adjacent waves produce continuous above the horizon coverage within said gap, and

whereby the orbit planes do not need to be fully populated with satellites and whereby a constellation having asymmetric arrangements of satellites in orbit planes can provide continuous above the horizon coverage at a given altitude of orbit.

23. The method defined in claim 22 wherein the great circle on the earth is the equator.

24. The invention defined in claim 23 wherein there are equal spacings between the orbital planes at the equator.

25. The invention defined in claim 22 wherein the cone of each satellite in the first cluster is entirely overlapped and covered by the coverage of one or more other satellites within the cluster.

26. The invention defined in claim 22 wherein the satellites are evenly spaced from one another within said clusters except for the spacing between the leading satellite and the trailing satellite.

27. The invention defined in claim 22 wherein the satellites within each cluster are unevenly spaced with respect to one another but each cluster has the same relative positioning of specific satellites within the cluster.

28. The invention defined in claim 22 wherein each orbit plane has only one asymmetric cluster of satellites in the orbit plane and wherein the phasing of the orbits form two cycle waves.

29. The invention defined in claim 22 wherein each orbit plane has a second asymmetric cluster of satellites within the orbit ring and wherein the orbit planes are phased to produce three cycle waves.

30. A constellation of satellites deployed in an asymmetric open rosette architecture rotating about the earth, said constellation being of the kind which has multiple inclined orbital planes with satellites in each orbital plane asymmetrically spaced in a cluster so as to leave an open space or gap between a trailing satellite and a leading satellite in each of the orbital planes of the constellation, said constellation comprising,

a first cluster of satellites in a first asymmetrical spacing in a first orbital plane inclined at a first angle with respect to a reference circle extending about the earth,

said first cluster having a leading satellite and a trailing satellite,

said first cluster of satellites populating only a portion of the orbital plane so as to leave a first open space or gap between the trailing satellite and the leading satellite in said first inclined orbital plane,

additional clusters of satellites placed in asymmetrical spacings in additional inclined orbital planes and wherein each additional inclined orbital plane has the same inclination angle as said first inclined orbital plane, has the same cluster of satellites as in said first cluster, has the same asymmetrical spacing as said first asymmetrical spacing, and has the same open space as said first open space,

said first and additional orbital planes being distributed about said reference circle,

all of the satellites being phased so that corresponding satellites in each orbital plane all reside on a single wave form which rotates about the celestial body on an axis normal to the plane of reference for the inclination angle of the planes, and wherein the wave form has at least two cycles, and wherein there is a leading wave form containing a leading satellite in each orbital plane and a trailing wave form containing a trailing satellite in each orbital plane.

31. The invention defined in claim 30 wherein the number of satellites in the partially filled orbital planes and the space between the satellites in each orbital plane and the relative phasing of each orbital plane are sufficient to fill the space between the leading and trailing wave forms so that the entire earth can be covered in single layers of satellite coverage patterns at least up to some desired latitude from said reference circle.

32. The invention defined in claim 30 wherein the single wave form is a wave form having two cycles.

33. The invention defined in claim 30 wherein at least one extra satellite is deployed in each orbit plane.

34. The invention defined in claim 30 wherein extra satellites are deployed in a parking orbit about the earth.

35. The invention defined in claim 34 wherein satellites from the parking orbit have been repositioned to replace certain satellites in certain orbit planes or to change the spacing of all of the satellites in all of the orbit planes.

36. The invention defined in claim 30 wherein additional satellites have been added to the orbit planes to fully populate the orbit planes and to provide double coverage for stereo.

37. The invention defined in claim 30 wherein certain satellites in certain orbit planes have been deleted to produce a hexagon configuration with an open center between related satellites in three related, adjacent wave forms.

38. The invention defined in claim 30 wherein a length of said first cluster of satellites is more than 180°

measured from the leading satellite to the trailing satellite in the cluster.

39. The invention defined in claim 30 wherein all of the orbit planes have been phased so that there is a shear zone between the descending waves and the ascending waves and so that the descending waves are close to, but do not overlap, the ascending waves.

40. The invention defined in claim 30 wherein all of the orbit planes have been phased so that there is a shear zone between the descending waves and the ascending waves and so that there is a slight overlap between the leading and trailing satellites of a descending wave and of an ascending wave in the shear zone.

41. The invention defined in claim 30 including at least one ground station for communicating with one or more satellites in said constellation.

42. The invention defined in claim 30 wherein there is equal spacing between each satellite and each adjacent satellite in each first cluster except for the spacing between the leading satellite and the trailing satellite in the cluster.

43. The invention defined in claim 30 wherein the desired coverage of the earth has been determined and wherein the asymmetric spacing in each orbital plane has been configured as required to obtain the desired coverage in single layers.

44. The invention defined in claim 30 wherein each satellite has an angle of coverage looking down at the earth.

45. The invention defined in claim 30 wherein the satellites have an angle of coverage which looks above the horizon of the celestial body.

46. The invention defined in claim 45 wherein all of the satellites in all of the clusters are positioned at an altitude with respect to the earth such that each satellite has a cone of non-coverage in its zone of above the horizon coverage because of visual impairment which can be caused by the earth and which can be caused also in at least some cases by an atmosphere layer surrounding the earth,

the satellites are positioned in a first cluster in certain orbit planes such that said cones in the above the horizon coverage of each of the satellites in the cluster are at least partially covered by the coverage of one or more other satellites within said first cluster,

said trailing satellite in said first cluster is spaced so far from the leading satellite in said first cluster that (a) there is a gap in the above the horizon coverage between the trailing satellite and the leading satellite in said first cluster and (b) the gap in the above the horizon coverage must be covered by one or more other satellites either in one or more other orbit planes or in one or more other clusters in the same orbit plane,

the orbits of said first clusters of satellites in said certain orbit planes are phased so that the satellites in said clusters form waves in which at least certain ones of satellites in one or more adjacent waves produce continuous above the horizon coverage within the gap, and

whereby the orbit planes do not need to be fully populated with satellites and whereby a constellation having asymmetric arrangements of satellites in orbit planes can provide continuous above the horizon coverage at a given altitude of orbit.

47. A constellation of satellites positioned in coherent waves in an asymmetric open rosette architecture so as to provide above the horizon coverage which extends into cones of non-coverage of individual satellites in the constellation and in such and which also extends into the gaps between trailing and leading satellites in asymmetric clusters of satellites in orbit planes of the constellation, such constellation comprising,

a constellation of satellites having a plurality of generally circular orbit planes,

each orbit plane being inclined at the same angle with respect to a reference great circle on the earth,

each orbit plane having an asymmetric cluster of satellites in the orbit plane,

each cluster of satellites having a leading satellite and a trailing satellite in the cluster,

all of the satellites in all of the clusters being positioned at an altitude with respect to the sphere such that each satellite has a cone of non-coverage in its zone of above the horizon coverage because of visual impairment which can be caused by the earth and which can be caused also in at least some cases by an atmosphere layer surrounding the earth,

the satellites in certain orbit planes being positioned in a first cluster such that said cones in the above the horizon coverage of each of the satellites in the cluster are at least partially overlapped and at least partially covered by the coverage of one or more other satellites within said first cluster,

said trailing satellite in said first cluster being spaced so far from the leading satellite in said first cluster that (a) there is a gap in the above the horizon coverage between the trailing satellite and the leading satellite in said first cluster and (b) said gap in the above the horizon coverage must be covered by one or more other satellites either in one or more other orbit planes or in one or more other clusters in the same orbit plane,

the orbits of said first clusters of satellites in said certain orbit planes being phased so that the satellites in said clusters form waves in which at least certain ones of satellites in one or more adjacent waves produce continuous above the horizon coverage within said gap, and

whereby the orbit planes do not need to be fully populated with satellites and whereby a constellation having asymmetric arrangements of satellites in orbit planes can provide continuous above the horizon coverage at a given altitude of orbit.

48. The invention defined in claim 47 wherein the great circle on the earth is the equator.

49. The invention defined in claim 48 wherein there are equal spacings between the orbital planes at the equator.

50. The invention defined in claim 47 wherein the cone of each satellite in the first cluster is entirely overlapped and covered by the coverage of one or more other satellites within the cluster.

51. The invention defined in claim 47 wherein the satellites are evenly spaced from one another within said clusters except for the spacing between the leading satellite and the trailing satellite.

52. The invention defined in claim 47 wherein the satellites within each cluster are unevenly spaced with respect to one another but each cluster has the same relative positioning of specific satellites within the cluster.

53. The invention defined in claim 47 wherein each orbit plane has only one asymmetric cluster of satellites in the orbit plane and wherein the phasing of the orbits form two cycle waves.

54. The invention defined in claim 47 wherein the orbit rings are phased to produce three cycle waves.

55. The invention defined in claim 47 wherein the orbit rings are phased to produce more than three cycle waves.