Low energy method for changing the inclinations of orbiting satellites using weak stability boundaries and a computer process for implementing same

• US 6,999,860 B2
• Filed: 03/22/2004
• Issued: 02/14/2006
• Est. Priority Date: 04/24/1997
• Status: Expired due to Fees

• Current Assignee: Galaxy Development LLC
• Original Assignee: Galaxy Development LLC
• Inventors: Belbruno, Edward A.
• Primary Examiner(s): Zanelli, Michael J.
• Assistant Examiner(s): Gibson, Eric M.
• Application Number:
  US10/805,374
• Publication Number:
  US 20040176883A1
• Time in Patent Office: 694 Days
• Field of Search: 701/3, 701/4, 701/13, 701/226, 244/158.R, 244/164, 244/167
• US Class Current: 701/13
• CPC Class Codes: B64G 1/242 Orbits and trajectories
• CPC Class Codes: B64G 1/2427 Transfer orbits
• CPC Class Codes: B64G 1/247 Advanced control concepts for autonomous, robotic spacecraft, e.g. by using artificial intelligence, neural networks or autonomous agents

Abstract

A fuel efficient technique for changing the inclination, with respect to the Earth'"'"'s equator, for a satellite includes first maneuvering the satellite to the moon on a BCT (Ballistic Capture Transfer). At the moon, the satellite is in the so-called fuzzy boundary or weak stability boundary. A negligibly small maneuver can then bring it back to the Earth on a reverse BCT to the desired Earth inclination. Another maneuver puts it into the new ellipse at the earth. In the case of satellites launched from Vandenberg AFB into LEO in a circular orbit of an altitude of 700 km with an inclination of 34°, approximately 6 km/s is required to change the inclination to 90°. The previous flight time associated with this method was approximately 170 days. A modification of this method also achieves a significant savings and unexpected benefits in energy as measured by Delta-V, where the flight time is also substantially reduced to 88 or even 6 days. Various alternative embodiments are disclosed.

Claims

1. A method of generating a transfer for an object emanating substantially at at least one of earth, earth orbit and a first heavenly location to arrive at at least one of the moon, moon orbit and a second heavenly location using a computer implemented process, comprising the steps of:

(a) entering parameters for said method of generating the transfer;

(b) implementing at least one of a forward targeting process and a forward transfer process to converge in a region of the at least one of the moon, the moon orbit and the second heavenly location; and

(c) iterating step (b) until sufficient convergence to obtain the transfer from the at least one of earth, the earth orbit and the first heavenly location to the at least one of the moon, the moon orbit and the second heavenly location.

2. A method of traveling from substantially from at least one of earth, earth orbit and a first heavenly location to at least one of the moon, moon orbit and a second heavenly location in a space vehicle or rocket using a transfer, comprising the steps of:

(a) generating the transfer by implementing at least one of a forward targeting process and a forward transfer process to converge at the at least one of the moon, the moon orbit and the second heavenly location; and

(b) traveling from substantially at the at least one of the earth, the earth orbit and the first heavenly location to the at least one of the moon, the moon orbit and the second heavenly location using the transfer by the space vehicle or the rocket.

3. A method of generating a transfer for an object emanating substantially at at least one of a first heavenly object, first heavenly object orbit and a first heavenly location to arrive at at least one of a second heavenly object, second heavenly object orbit and a second heavenly location, comprising the sequential, non-sequential or sequence independent step of:

(a) entering parameters for said method of generating the transfer;

(b) implementing at least one of a forward targeting process and a forward transfer process by varying the parameters to converge in a region of the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location from the first heavenly object, the first heavenly object orbit and the first heavenly location; and

(c) iterating step (b) until sufficient convergence to obtain the transfer from the at least one of the first heavenly object, the first heavenly object orbit and the first heavenly location to the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location.

4. A method according to claim 3, wherein said iterating step (c) further comprises the step of iterating step (b) until sufficient convergence to obtain the transfer from the at least one of the first heavenly object, the first heavenly object orbit and the first heavenly location to the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location via at least one of a weak capture trajectory and a weak stability boundary (WSB) orbit interposed therebetween.

5. A method according to claim 4, wherein said performing step (b) further comprises the step of performing the negligible maneuver of between 2-20 meters per second at the WSB or the WSB orbit for ejection therefrom.

6. A method according to claim 4, wherein the at least one of the WSB or the WSB orbit is realizable at the predetermined arbitrary altitude by specifying a predetermined velocity magnitude of the object, thereby defining a predetermined capture eccentricity.

7. A method according to claim 4, wherein the at least one of the WSB or the WSB orbit is nonlinear and being substantially at a boundary of capture and escape, thereby allowing the capture and the escape to occur for a substantially zero or relatively small maneuver.

8. A method according to claim 4, wherein a motion in the at least one of the WSB or the WSB orbit is at least one of parabolic and elliptic.

9. A method according to claim 4, wherein said implementing step (b) further comprises the step of generating a trajectory with respect to the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location comprising at least a negligible maneuver of between 2-20 meters per second at the weak capture trajectory or the WSB orbit for at least one of timing and positioning of at least one of a space vehicle, satellite and rocket, prior to ejection therefrom.

10. A method according to claim 3, wherein said implementing step (b) further comprises the step of implementing the at least one of the forward targeting process and the forward transfer process by varying at least two spherical parameters for convergence of the target variables at the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location, while maintaining at least one classical variable substantially fixed.

11. A method according to claim 3, wherein said implementing step (b) further comprises the step of implementing the at least one of the forward targeting process and the forward transfer process by varying velocity magnitude VE, and flight path angle *E for convergence of the target variables at the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location, the target variables including radial distance, rM, and inclination iM.

12. A method according to claim 11, further comprising the steps of:

(d) transforming converged values of VE, *E into classical elements;

(e) transforming the classical elements to spherical coordinates, wherein the spherical coordinates include the converged values of VE, *E, and longitude *E, latitude *E, flight path azimuth/angle with vertical *E are changed.

13. A method according to claim 11, wherein the velocity magnitude VE, and the flight path angle *E are decoupled from the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location in the transfer.

14. A method according to claim 11, wherein the velocity magnitude VE, and the flight path angle *E are decoupled from angular elements of the at least one of the first heavenly body, the first heavenly body orbit and the first heavenly location including inclination iE, ascending node relative to earth *E, and argument of periapsis relative to the first heavenly body *E.

15. A method according to claim 3, wherein said implementing step (b) further comprises the step of implementing the at least one of the forward targeting process and the forward transfer process comprising a second order Newton algorithm, and wherein the second order Newton algorithm utilizes two control variables including velocity magnitude VE, and flight path angle *E that are varied to achieve at least one of transfer and capture conditions at the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location using two target variables including radial distance, rM, and inclination iM.

16. A method according to claim 3, wherein said implementing step (b) further comprises the step of generating a trajectory around the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location comprising a negligible maneuver of between 2-20 meters per second at at least one of a weak stability boundary (WSB), WSB orbit and weak capture trajectory associated with the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location.

17. A method according to claim 16, wherein the WSB or the WSB orbit is nonlinear and being substantially at a boundary of capture and escape, thereby allowing the capture and the escape to occur for a substantially zero or relatively small maneuver, and wherein solar gravitational perturbations influence the first and second transfers.

18. A method according to claim 16, wherein the at least one of the WSB, the WSB orbit and the weak capture trajectory is substantially at a boundary of interaction between gravitational fields.

19. A method according to claim 16, wherein as at least one of a space vehicle, satellite and rocket moves in at least one of the at least one of the WSB, the WSB orbit and the weak capture trajectory, a Kepler energy of the at least one of a space vehicle, satellite and rocket is slightly negative and substantially near to zero.

20. A method according to claim 16, wherein the at least one of the WSB, the WSB orbit and the weak capture trajectory is realizable at the predetermined arbitrary altitude by specifying a predetermined velocity magnitude of the at least one of a space vehicle, satellite and rocket, thereby defining a predetermined capture eccentricity.

21. A method according to claim 3, wherein the forward targeting process is a second order Newton algorithm.

22. A method according to claim 3, wherein the first heavenly body or the first heavenly body orbit comprises earth or earth orbit, and wherein the second heavenly body or the second heavenly body orbit comprises moon or moon orbit.

23. A method according to claim 3, wherein said iterating atop (c) further comprises the step of iterating step (b) until sufficient convergence to obtain the transfer from the at least one of the first heavenly object, the first heavenly object orbit and the first heavenly location to the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location via at least one of a low energy transfer and a low energy orbit.

24. A method of traveling by an object emanating substantially from at least one of a first heavenly object, first heavenly object orbit and a first heavenly location to arrive at at least one of a second heavenly object, second heavenly object orbit and a second heavenly location using a transfer, comprising the sequential, non-sequential or sequence independent steps of:

(a) generating the transfer by implementing at least one of a forward targeting process and a forward transfer process to converge in a region of the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location; and

(b) traveling from substantially from the at least one of the first heavenly object, the first heavenly object orbit and the first heavenly location to the at least one of the second heavenly object, second heavenly object orbit and the second heavenly location using the transfer by the object.

25. A method according to claim 24, wherein said iterating step (c) further comprises the step of iterating step (b) until sufficient convergence to obtain the transfer from the at least one of the first heavenly object, the first heavenly object orbit and the first heavenly location to the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location via at least one of a low energy transfer and a low energy orbit.

26. A method according to claim 25, wherein said implementing step (b) further comprises the step of generating a trajectory with respect to the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location comprising at least a negligible maneuver of between 2-20 meters per second at the via the at least one of the low energy transfer and the low energy orbit, for at least one of dining and positioning of at least one of a space vehicle, satellite and rocket, prior to ejection therefrom.

27. A method according to claim 25, wherein said implementing step (b) further comprises the step of implementing the at least one of the forward targeting process and the forward transfer process by varying at least two spherical parameters for convergence of the target variables at the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location, while maintaining at learnt one classical variable substantially fixed.

28. A method according to claim 25, wherein said implementing step (b) further comprises the step of implementing the at least one of the forward targeting process and the forward transfer process by varying velocity magnitude VE, and flight path angle *E for convergence of the target variables at the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location, the target variables including radial distance, rM, and inclination iM.

29. A method according to claim 28, further comprising the steps of:

(d) transforming converged values of VE, *E into classical elements;

(e) transforming the classical elements to spherical coordinates, wherein the spherical coordinates include the converged values of VE, *E, and longitude *E, latitude *E, flight path azimuth/angle with vertical *E are changed.

30. A method according to claim 28, wherein the velocity magnitude VE, and the flight path angle *E are decoupled from the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location in the transfer.

31. A method according to claim 28, wherein the velocity magnitude VE, and the flight path angle *E are decoupled from angular elements of the at least one of the first heavenly body, the first heavenly body orbit and the first heavenly location including inclination iE, ascending node relative to earth *E, and argument of periapsis relative to the first heavenly body *E.

32. A method according to claim 25, wherein said implementing step (b) further comprises the step of implementing the at least one of the forward targeting process and the forward transfer process comprising a second order Newton algorithm, and wherein the second order Newton algorithm utilizes two control variables including velocity magnitude VE, and flight path angle *E that are varied to achieve at least one of transfer and capture conditions at the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location using two target variables including radial distance, rM, and inclination iM.

33. A method according to claim 25, wherein said implementing step (b) further comprises the step of generating a trajectory around the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location comprising a negligible maneuver of at least one of a weak stability boundary (WSB), WSB orbit, low energy transfer and weak capture associated with the at least one of the second heavenly body, the second heavenly body orbit and the second heavenly location.

34. A method according to claim 33, wherein the at least one of the WSB, the WSB orbit, the low energy transfer and the weak capture is nonlinear and being substantially at a boundary of capture and escape, thereby allowing the capture and the escape to occur for a substantially zero or relatively small maneuver.

35. A method according to claim 33, wherein the at least one of the WSB, the WSB orbit, the low energy transfer and the weak capture is substantially at a boundary of interaction between gravitational fields.

36. A method according to claim 33, wherein as at least one of a space vehicle, satellite and rocket moves in wherein the at least one of the WSB, the WSB orbit, the low energy transfer and the weak capture, a Kepler energy of the at least one of a space vehicle, satellite and rocket is slightly negative and substantially near to zero.

37. A method according to claim 33, wherein the at least one of the WSB, the WSB orbit, the low energy transfer and the weak capture is realizable at the predetermined arbitrary altitude by specifying a predetermined velocity magnitude of the at least one of a apace vehicle, satellite and rocket, thereby defining a predetermined capture eccentricity.

38. A method according to claim 25, wherein the forward targeting process is a Newton algorithm.

39. A method according to claim 25, wherein the first heavenly body or the first heavenly body orbit comprises earth or earth orbit, and wherein the second heavenly body or the second heavenly body orbit comprises moon or moon orbit.

40. A spacecraft or satellite implementing a method of traveling from substantially at least one of a first heavenly object, a first heavenly object orbit and a first heavenly location to arrive at at least one of a second heavenly object, a second heavenly object orbit and a second heavenly location using a transfer, wherein the transfer is generated via at least one of said spacecraft, said satellite and a remote system, by implementing at least one of a forward targeting process and a forward transfer process to converge in a region of the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location;

and said spacecraft or said satellite travel from substantially at the at least one of the first heavenly object, the first heavenly object orbit and the first heavenly location to the at least one of the second heavenly object, the second heavenly object orbit and the second heavenly location using the transfer.