Procedure for generating operational ballistic capture transfer using a computer implemented process

• US 6,442,482 B1
• Filed: 07/27/2001
• Issued: 08/27/2002
• Est. Priority Date: 02/04/1997
• 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:
  US09/915,565
• Time in Patent Office: 396 Days
• Field of Search: 701/3, 701/4, 701/13, 701/226, 244/158.R, 244/164, 244/167
• US Class Current: 701/226
• CPC Class Codes: B64G 1/1064 specifically adapted for interplanetary, solar or interstellar exploration
• CPC Class Codes: B64G 1/242 Orbits and trajectories
• CPC Class Codes: B64G 1/2427 Transfer orbits

Abstract

A method generates an operational ballistic capture transfer for an object emanating substantially at earth or earth orbit to arrive at the moon or moon orbit using a computer implemented process. The method includes the steps of entering parameters including velocity magnitude V_E, flight path angle γ_E, and implementing a forward targeting process by varying the velocity magnitude V_E, and the flight path angle γ_E for convergence of target variables at the moon. The target variables include radial distance, r_M, and inclination i_M. The method also includes the step of iterating the forward targeting process until sufficient convergence to obtain the operational ballistic capture transfer from the earth or the earth orbit to the moon or the moon orbit.

Claims

1. A method of generating a capture transfer for an object emanating substantially at earth or earth orbit to arrive at the moon or moon orbit using a computer implemented process, comprising the steps of:

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

(b) implementing a forward targeting process by varying the parameters for convergence of target variables at the moon; and

(c) iterating step (b) until sufficient convergence to obtain the capture transfer from the earth or the earth orbit to the moon or the moon orbit.

2. A method of traveling from substantially at earth or earth orbit to the moon or moon orbit in a space vehicle or rocket using a capture transfer, comprising the steps of:

(a) generating the capture transfer by implementing a forward targeting process by varying parameters for said method until convergence of target variables at the moon; and

(b) traveling from substantially at the earth or the earth orbit to the moon or the moon orbit using the capture transfer by the space vehicle or the rocket.

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

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

(b) implementing a forward targeting process by varying the parameters for convergence of target variables at the second heavenly object or the second heavenly object orbit from the first heavenly object or the first heavenly object orbit; and

(c) iterating step (b) until sufficient convergence to obtain the capture transfer from the first heavenly object or the first heavenly object orbit to the second heavenly object or the second heavenly object orbit.

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 capture transfer from the first heavenly object or the first heavenly object orbit to the second heavenly object or the second heavenly object orbit via a weak stability boundary (WSB) orbit interposed therebetween.

5. A method according to claim 4, wherein said implementing step (b) further comprises the step of generating a trajectory around the second heavenly body or the second heavenly body orbit comprising at least a negligible maneuver of between 2-20 meters per second at the WSB 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.

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

7. A method according to claim 3, wherein said implementing step (b) further comprises the step of implementing the forward targeting process by varying velocity magnitude V_E, and flight path angle γ

_E for convergence of the target variables at the second heavenly object or the second heavenly object orbit, the target variables including radial distance, r_M, and inclination i_M.

8. A method according to claim 7, further comprising the steps of:

(d) transforming converged values of V_E, γ

_E into classical elements;

(e) transforming the classical elements to spherical coordinates, wherein the spherical coordinates include the converged values of V_E, γ

_E, and longitude α

_E, latitude δ

_E, flight path azimuth/angle with vertical σ

_E are changed.

9. A method according to claim 7, wherein the velocity magnitude V_E, and the flight path angle γ

_E are decoupled from the second heavenly body or the second heavenly body orbit in the capture transfer.

10. A method according to claim 7, wherein the velocity magnitude V_E, and the flight path angle γ

_E are decoupled from angular elements of the first heavenly body including inclination i_E, ascending node relative to earth Ω

_E, and argument of periapsis relative to the first heavenly body ω

_E.

11. A method according to claim 3, wherein said implementing step (b) further comprises the step of implementing the forward targeting process comprising a second order Newton algorithm, and wherein the second order Newton algorithm utilizes two control variables including velocity magnitude V_E, and flight path angle γ

_E that are varied to achieve capture conditions at the second heavenly body or the second heavenly body orbit using two target variables including radial distance, r_M, and inclination i_E.

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

13. A method according to claim 12, 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.

14. A method according to claim 12, wherein the WSB or the WSB orbit is substantially at a boundary of interaction between gravitational fields of the first heavenly body and the second heavenly body.

15. A method according to claim 12, wherein as at least one of a space vehicle, satellite and rocket moves in at least one of the WSB or the WSB orbit, a Kepler energy of the at least one of a space vehicle, satellite and rocket is slightly negative and substantially near to zero.

16. A method according to claim 12, 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 at least one of a space vehicle, satellite and rocket, thereby defining a predetermined capture eccentricity.

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

18. 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.

19. A method of traveling by an object emanating substantially at a first heavenly object or first heavenly object orbit to arrive at a second heavenly object or second heavenly object orbit using a capture transfer, comprising the sequential, non-sequential or sequence independent steps of:

(a) generating the capture transfer by implementing a forward targeting process by varying parameters for said method until substantial convergence of target variables at the second heavenly object or the second heavenly object orbit; and

(b) traveling from substantially at the first heavenly object or first heavenly object orbit to the second heavenly object or second heavenly object orbit using the capture transfer by the object.

20. A spacecraft or satellite implementing a method of traveling from substantially a first heavenly object or first heavenly object orbit to arrive at a second heavenly object or second heavenly object orbit using a capture transfer, wherein the capture transfer is generated via at least one of said spacecraft, said satellite and a remote system, by implementing a forward targeting process by varying parameters for said method until substantial convergence of target variables at the second heavenly object or the second heavenly object orbit;

and said spacecraft or said satellite travel from substantially at the first heavenly object or first heavenly object orbit to the second heavenly object or second heavenly object orbit using the capture transfer.