Back to results
US 8,998,146 B2Granted
Spacecraft momentum unload and station-keeping techniques
AssigneeSpace Systems/Loral, Inc.
InventorsByoungsam Woo, Farid Ganji, John Hutton Cooper
Life of this patent
Estimating the term…
Abstract
Spacecraft momentum management techniques are coordinated with station-keeping maneuvers or other delta-V maneuvers. A body stabilized spacecraft attitude is controlled, the spacecraft including at least one momentum/reaction wheel, and a set of thrusters. A first momentum storage deadband limit is adjusted, the adjustment being related to a first delta-V maneuver window. A momentum management strategy is executed with the adjusted first momentum storage deadband limit such that a first thruster firing that performs desaturation of the momentum/reaction wheel also provides velocity change beneficial to the first delta-V maneuver.
Claims36
A method comprising:
- controlling an attitude of a body stabilized spacecraft, the spacecraft comprising at least one momentum/reaction wheel configured to maintain the attitude with respect to a spacecraft axis by storing momentum, and a set of thrusters, the controlling including:
- executing a momentum management strategy coordinated with a first delta-V maneuver, the first delta-V maneuver to be conducted by firing a first thruster during a first window for conducting the first delta-V maneuver, the momentum management strategy including:
- shifting a first momentum storage deadband limit;
- and
- firing a second thruster such that impulse from the second thruster desaturates the momentum/reaction wheel in conformance with the shifted first momentum storage deadband limit, and, at the same time, also provides a velocity change beneficial to the first delta-V maneuver;
- wherein
- the momentum management strategy complies with one or both of a first condition and a second condition, the first condition being that the first thruster is different from the second thruster, and the second condition being that firing the second thruster to desaturate the momentum/reaction wheel occurs at least partially outside the first window.
4 more elements
A method comprising:
- controlling an attitude of a 3-axis stabilized spacecraft attitude, the spacecraft being in geosynchronous orbit, and comprising at least one momentum/reaction wheel configured to maintain the attitude with respect to an axis by storing momentum, and a set of thrusters, the controlling including:
- executing a momentum management strategy coordinated with a first north south statinkeeping (NSSK) maneuver, the first NSSK maneuver to be conducted by firing a first thruster during a first window for conducting the first NSSK maneuver, the momentum management strategy including:
- shifting a first momentum storage deadband limit;
- and
- firing a second thruster such that impulse from the second thruster desaturates the momentum/reaction wheel in conformance with the shifted first momentum storage deadband limit, and, at the same time, also provides a velocity change beneficial to the first NSSK maneuver;
- wherein
- the momentum management strategy complies with one or both of a first condition and a second condition, the first condition being that the first thruster is different from the second thruster, and the second condition being that firing the second thruster to desaturate the momentum/reaction wheel occurs at least partially outside the first window.
4 more elements
A method comprising:
- controlling an attitude of a body stabilized spacecraft attitude, the spacecraft comprising at least one momentum/reaction wheel configured to maintain the attitude with respect to an axis by storing momentum, and a set of thrusters, the controlling including:
- executing a momentum management strategy coordinated with a first delta-V maneuver, the first delta-V maneuver to be conducted by firing a first thruster during a first window for conducting the first delta-V maneuver, the momentum management strategy including:
- making a first adjustment to a momentum storage deadband, the first adjustment being coordinated with the first window, the first adjustment comprising:
- a widened deadband proximate to and prior to the first window, and
- a narrowed deadband during the first window;
- and
- firing a second thruster, different from the first thruster, such that impulse from the second thruster firing desaturates the momentum/reaction wheel, and, at the same time, also provides a velocity change beneficial to the first delta-V maneuver.
4 more elements
A body stabilized spacecraft, the spacecraft comprising:
- at least one momentum/reaction wheel configured to control a spacecraft attitude with respect to an axis by storing momentum;
- a set of thrusters;
- and
- a controller communicatively coupled with the at least one momentum/reaction wheel and the set of thrusters, the controller programmed to:
- execute a momentum management strategy coordinated with a first delta-V maneuver, the first delta-V maneuver to be conducted by firing a first thruster during a first window for conducting the first delta-V maneuver, the momentum management strategy including:
- shifting a first momentum storage deadband limit;
- and
- firing a second thruster such that impulse from the second thruster desaturates the momentum/reaction wheel in conformance with the shifted first momentum storage deadband limit, and, at the same time, also provides a velocity change beneficial to the first delta-V maneuver;
- wherein
- the momentum management strategy complies with one or both of a first condition and a second condition, the first condition being that the first thruster is different from the second thruster, and the second condition being that firing the second thruster to desaturate the momentum/reaction wheel occurs at least partially outside the first window.
7 more elements
A body stabilized spacecraft configured for operation in geosynchronous orbit, the spacecraft comprising:
- at least one momentum/reaction wheel configured to control a spacecraft attitude with respect to an axis by storing momentum;
- a set of thrusters;
- and
- a controller communicatively coupled with the at least one momentum/reaction wheel and the set of thrusters, the controller programmed to:
- execute a momentum management strategy coordinated with a first north south stationkeeping (NSSK) maneuver, the first NSSK maneuver to be conducted by firing a first thruster during a first window for conducting the first NSSK maneuver, the momentum management strategy including:
- shifting a first momentum storage deadband limit;
- and
- firing a second thruster such that impulse from the second thruster desaturates the momentum/reaction wheel in conformance with the shifted first momentum storage deadband limit, and, at the same time, also provides a velocity change beneficial to the first NSSK maneuver;
- wherein
- the momentum management strategy complies with one or both of a first condition and a second condition, the first condition being that the first thruster is different from the second thruster, and the second condition being that firing the second thruster to desaturate the momentum/reaction wheel occurs at least partially outside the first window.
7 more elements
A body stabilized spacecraft, the spacecraft comprising:
- at least one momentum/reaction wheel configured to control a spacecraft attitude with respect to an axis by storing momentum;
- a set of thrusters;
- and
- a controller communicatively coupled with the at least one momentum/reaction wheel and the set of thrusters, the controller programmed to:
- execute a momentum management strategy coordinated with a first delta-V maneuver, the first delta-V maneuver to be conducted by firing a first thruster during a first window for conducting the first delta-V maneuver, the momentum management strategy including:
- making a first adjustment to a momentum storage deadband, the first adjustment being coordinated with the first window, the first adjustment comprising:
- a widened deadband proximate to and prior to the first window, and
- a narrowed deadband during the first window;
- and
- firing a second thruster, different from the first thruster, such that impulse from the second thruster firing desaturates the momentum/reaction wheel, and, at the same time, also provides a velocity change beneficial to the first delta-V maneuver.
7 more elements
Dependencies are inferred from the claim text.