Solar powered system for a space vehicle

• US 5,228,644 A
• Filed: 05/28/1991
• Issued: 07/20/1993
• Est. Priority Date: 05/28/1991
• Status: Expired due to Fees

• Current Assignee: AEC-Able Engineering Company, Inc., Teledyne Industries Incorporated (Teledyne Technologies Incorporated)
• Original Assignee: United States Administrator of National Aeronautics and Space Administration
• Inventors: Jones, Philip A., Harvey, Thomas J., Garriott, Owen K.
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): Mattix, Carla
• Application Number:
  US07/705,807
• Time in Patent Office: 784 Days
• Field of Search: 244/173, 244/158 R
• US Class Current: 244/172.6
• CPC Class Codes: B64G 1/14 Space shuttles reusable launch rockets B64G1/006
• CPC Class Codes: B64G 1/222 for deploying structures between a stowed and deployed state
• CPC Class Codes: B64G 1/443 Photovoltaic cell arrays
• CPC Class Codes: Y10S 136/292 Space - satellite

Abstract

A solar power system for use with a space vehicle for achieving extended mission duration is disclosed. The solar power system includes sets of foldable solar panel casings which are unfolded and extended to the starboard and port sides (±Y axis) of the space vehicle. During stowage the laterally offset sets of casings are placed in an overlapping arrangement to reduce the lateral space occupied within the payload bay of the host space vehicle. The casings are further extended away from the space vehicle by extending an extendable boom along the ±Y axis. The extendable boom preferably includes a first and second boom section rotatably attached at their inboard end of the support structure. The solar panels contained within the casings are extended in a ±Z axis and a hinge is provided between the ends of the boom sections ad the casings such that the deployed panels can rotate about the ±Z axis. A pitch drive motor rotates the boom sections about the ±Y axis.

Claims

1. A solar power system for use with a space vehicle in orbit, the space vehicle having a payload bay and, for reference, a ±

X axis extending in the direction of orbit, a ±

Y axis extending to opposite sides of the payload bay and perpendicular to the ±

X axis, a ±

Z axis extending perpendicular to said ±

X and ±

Y axes and through the payload bay, and, when in orbit, the X-Z plane of the space vehicle coincides with the orbital plane of the space vehicle, comprising;

a support structure fixed within the payload bay of the space vehicle;

a boom;

means for extending and retracting said boom along the ±

Y axis;

rotation means for rotating said boom about the ±

Y axis;

means for attaching said boom to said support structure, and said attachment means and support structure being dimensioned and arranged such that said boom has a z-axis level during stowage within the payload bay which is the same as the z-axis level of said boom when said boom is being extended and retracted by said extending and retracting means; and

solar panels supported by said boom.

2. A solar power system as recited in claim 1, wherein said boom includes a first boom section with an inboard end, said first boom section being adapted for extension by said extension and retraction means out away from one side of said support structure, and a second boom section with an inboard end which is adapted for extension by said extension and retraction means out away from an opposite side of said support structure, said first and second boom sections being attached to said attachment means, and said rotation means including drive means to rotate the inboard ends of said boom sections.

3. A solar power system as recited in claim 2, further comprising first and second boom canisters and said rotation means including a shaft connected to and extending between said boom canisters, said first boom section adapted for stowage within said first boom canister, said second boom section adapted for stowage within said second boom canister, and wherein said first and second boom sections share a common central axis with said shaft.

4. A solar power system as recited in claim 3, wherein said rotation means rotates said shaft such that said first and second boom sections rotate synchronously about the ±

Y axis.

5. A solar power system as recited in claim 1, further comprising storage means for storing said solar panels in a storage state;

deployment-retraction means for drawing said solar panels from said storage means and for retracting said solar panels into said storage means;

said boom including first and second boom sections extending to opposite sides of said support structure; and

said power system further comprising securement means for securing said storage means to an external end of said first and second boom sections.

6. A solar power system as recited in claim 5, wherein said securement means comprises first and second beta angle hinges connected to said solar panel storage means and wherein said first beta angle hinge is connected to the external end of said first boom section and said second beta angle hinge is connected to the external end of said second boom section, said storage means including first and second casing assemblies with each casing assembly having a first pair of casings pivotably joined to one another and a second pair of casings pivotably joined to one another, said casing assemblies further including a mast canister extending between said first and second pairs of casings in a respective one of said casing assemblies, and said mast canisters being joined to said beta angle hinges.

7. A solar power system as recited in claim 6, wherein the casings in said first pair of casings are adapted for folding one upon another and for pivoting away from one another so as to further extend along the ±

Y axis, and wherein the casings in said second pair of casings are adapted for folding one upon another and for pivoting away from one another so as to further extend along the ±

Y axis.

8. A solar power system as recited in claim 7, wherein said mast canister of said first casing assembly includes a first portion extending to one side of said first beta angle hinge and a second portion extending on the opposite side of said first beta angle hinge and said first portion extending further away than said second portion, and said mast canister of said second casing assembly having a first portion extending to one side of said second beta angle hinge and a second portion extending to the opposite side, and said second portion extending further out away from said second beta angle hinge than said first portion such that each pair of casings in said first casing assembly is laterally offset from each pair of casings in said second casing assembly whereby the casings in said casing assemblies, when in a stowage position, extend past one another in a direction along the ±

Y axis.

9. A solar power system as recited in claim 6, further comprising electrical lines extending along said first and second boom sections and electrically connected to said solar panels, said beta angle hinges having about (±

65°

) pivot range, and said electrical line including a flex cable extending past said beta angle hinge.

10. A solar power system as recited in claim 1, further comprising a momentum wheel assembly having a momentum wheel adapted for rotation about an axis parallel to the ±

Y axis.

11. A solar power system as recited in claim 1, wherein said means for attachment attaches said boom to said support structure so as to be non-rotatable about the z-axis whereby there is avoided only development of a moment about the z-axis due to said boom either before or during an extension or retraction of said boom along the ±

Y axis.

12. A solar power system for use with a space vehicle in orbit, the space vehicle having, for reference, a ±

X axis extending forward to aft, a ±

Y axis extending port to starboard;

a ±

Z axis extending above and below the space vehicle, and, when in orbit, the X-Z plane of the space vehicle coincides with the orbital plane of the space vehicle, said solar power system comprising;

an extendable and retractable boom which, when extended, extends to port and starboard along the ±

Y axis of the space vehicle;

a first beta angle hinge connected to a first external end of said boom and a second beta angle hinge connected to a second external end of said boom;

support means joined to the space vehicle for supporting said boom;

means for attaching said boom to said support means;

means for rotating said boom about the ±

Y axis;

means for extending said boom from a retracted position to the extended position;

solar panels;

solar panel storage means for storing said solar panels, said storage means including a first casing assembly secured to said first beta angle hinge and a second casing assembly secured to said second beta angle hinge, said first casing assembly including a first pair of solar panel casings and a pivot joint pivotably connecting said first pair of solar panel casings such that a casing in said first pair is foldable onto the other casing in that pair and adapted for pivoting at the pivot joint about an axis parallel to the ±

X axis so as to extend along the direction of the ±

Y axis, and said second casing assembly including a first pair of solar panel casings and a pivot joint pivotably connecting said first pair of solar panel casings such that a casing in the pair is foldable onto the other casing in that pair and is adapted for pivoting at the pivot joint about an axis parallel to the ±

X axis so as to extend along in the direction of the -Y axis, and

said first casing assembly including a second pair of solar panel casings pivotably joined and a mast canister secured to said first beta angle hinge and extending between said first and second pairs of casings in said first casing assembly, and said second casing assembly including a second pair of solar panel casings and a mast canister secured to said second beta angle hinge and positioned between said first and second pairs of casings in said second casing assembly.

13. A solar power system as recited in claim 12, wherein said mast canisters include a first and a second portion and said first portion of a first of said mast canisters is longer than the first portion of a second of said mast canisters and the second portion of said first mast canister is shorter than the second portion of said second mast canister such that the pairs of casings in said first casing assembly are laterally offset from the pairs casings in said second casing assembly so that said casings in said first casing assembly overlap along the Y axis with the casings in said second casing assembly when said casing assemblies are in a stowage mode.

14. A solar power system as recited in claim 12, further comprising a momentum wheel assembly supported by said supporting means, said momentum wheel assembly including a momentum wheel adapted for pivoting about an axis parallel to the ±

Y axis.

15. A solar power system for use with a space vehicle, comprising:

a support base;

an extendable boom positioned within a payload bay of the space vehicle while in a stowage mode;

attachment means for attaching said boom to said support base;

rotation means for rotating said boom about an alpha axis extending longitudinally along said boom;

extension means for extending said boom out away from said support base along the alpha axis;

solar panels;

solar panel storage means for storing said solar panels;

securement means for securing said storage means to said extendable boom;

means for deploying and retracting said solar panels away from and into said storage means;

said securement means including beta angle hinges for pivoting said solar panels about a beta axis which beta axis extends essentially perpendicular to the alpha axis of said boom and in a direction essentially parallel with the direction said solar panels are extended by said deploying and retracting means; and

said storage means including pairs of solar panel casings wherein each casing in a pair is joined by a pivot joint to the other casing in that pair, and means for unfolding one of the casings in each pair outwardly along the alpha axis, and wherein said first and second beta angle hinges are secured to respective external ends of said boom, and said storage means includes a first mast canister extending between two of said pairs of jointed casings and secured to said first beta angle hinge and a second mast canister extending between an additional two of said pairs of jointed casings and secured to said second beta angle hinge.

16. A solar panel system as recited in claim 15, wherein, for reference, a z-axis extends perpendicular to said alpha axis and beta axis, and wherein said support base and said attachment means are dimensioned and arranged such that said boom has a z-axis level during the stowage mode which is the same as the z-axis level of said boom when said boom is being extended and retracted.

17. A solar power system as recited in claim 15, further comprising a momentum wheel assembly supported by said support structure, said momentum wheel including a momentum wheel adapted to pivot about an axis parallel to the alpha axis.

18. A solar power system as recited in claim 15, wherein said attachment means includes means for jettisoning said boom out of the payload bay, and said means for jettisoning including means for releasing said boom from attachment with said support base such that payload doors of the payload bay are closeable following the jettisoning of said boom out of the payload bay.

19. A solar power system as recited in claim 15, wherein said support structure includes a cold plate positioned below said attachment means and said solar power system further comprising means for cooling said cold plate.

20. A solar power system as recited in claim 19 further comprising a plurality of batteries supported by said support structure and in contact with said cold plate.

21. A solar power system as recited in claim 15 comprising a redundant power system comprised of solar cells, a shunting unit to control the use of the power from the solar cells, a battery bank comprised of multiple cell stacks, and a control and data acquisition computer to manage solar tracking, battery charging, and battery bank power levels.

22. A method of providing solar power to a space vehicle in orbit, comprising:

extending a retracted first boom section to one side of the space vehicle along an alpha axis;

extending a retracted second boom section to the opposite side of the space vehicle along the alpha axis;

pivoting a first of a first pair of solar panel casings joined to said first boom section out further away from the space vehicle along the alpha axis;

pivoting a first of a second pair of solar panel casings joined to said second boom section out further away from the space vehicle along the alpha axis; and

deploying said solar panels from said solar casings in a direction transverse to the alpha axis;

synchronously rotating said boom sections about the alpha axis so as to rotate said panels to track the sun; and

derotating said first and second boom sections on a dark side portion of the orbit such that flex cables extending along said first and second boom sections are unwound.

23. A method as recited in claim 22, further comprising the step of retaining said boom sections at the same height with respect to the space vehicle when said boom sections are in stowage and when said boom sections are being extended.

24. A method as recited in claim 22, further comprising rotating said solar panel casings about a beta angle hinge connected at the external ends of said first and second boom sections.

25. A method as recited in claim 22, further comprising rotating said solar panel casings about a beta angle hinge connected at the external ends of said first and second boom sections.

26. A method as recited in claim 22, further comprising rotating a momentum wheel to negate momentum created by rotation of said boom sections.

27. A method as recited in claim 22, wherein said step of deploying said solar panels includes maintaining the center of gravity of said solar powered space vehicle at essentially the same place during solar panel stowage and solar power operation through symmetrical deployment of said solar power panels from a support base which is fixed at the same height during deployment and stowage.

28. A method for providing solar power derived from the sun to an orbiting space vehicle, which, for reference, has a ±

X axis extending forward to aft, a ±

Y axis extending port to starboard, a ±

Z axis extending above and below the space vehicle, and when in orbit, the X-Z plane of the space vehicle coincides with the orbital plane of the space vehicle, comprising;

placing said space vehicle in essentially a local vertical attitude and maintaining said space vehicle in essentially the local vertical attitude by pitching said space vehicle at essentially a constant pitch rate;

deploying boom sections which extend in the ±

Y direction, and then solar panels in a direction perpendicular to the direction of extension of the boom sections;

fixing, in solar inertial coordinates, the deployed solar panels positioned at the end of the boom sections, while said space vehicle orbits about the sunlit side of the orbit, by rotating said boom sections about the ±

Y axis in a first direction opposite to the pitch rotation and at essentially the same rate as the pitch rotation;

rotating said boom sections in a direction opposite to said first direction during a dark side portion of the orbit so as to unwind electric cables extending along said boom sections;

accelerating a momentum wheel to negate any change in momentum which develops during rotation of said boom sections in said first direction, during rotation of said boom sections in said second direction, and to stabilize and control any minor cyclic pitch excursions of the space vehicle.

29. A solar power system for use with a space vehicle having a payload bay comprising:

a support structure fixed within the payload bay of the space vehicle;

a boom;

means for extending and retracting said boom along an alpha axis extending to the sides of the payload bay;

rotation means for rotating said boom about the alpha axis;

means for attaching said boom to said support structure;

solar panels;

storage means for storing said solar panels in a storage state;

deployment-retraction means for drawing said solar panels from said storage means and for retracting said solar panels into said storage means;

said boom including first and second boom sections extending to opposite sides of said support structure; and

said power system further comprising securement means for securing said storage means to an external end of said first and second boom sections, said securement means comprising first and second beta angle hinges connected to said solar panel storage means and wherein said first beta angle hinge is connected to the external end of said first boom section and said second beta angle hinge is connected to the external end of said second boom section, said storage means including first and second casing assemblies with each casing assembly having a first pair of casings pivotably joined to one another and a second pair of casings pivotably joined to one another, said casing assemblies further including a mast canister extending between said first and second pairs of casings in a respective one of said casing assemblies, and said mast canisters being joined to said beta angle hinges.