Patents by Inventor Yiu-Hung M. Ho
Yiu-Hung M. Ho has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9309010Abstract: A first inclination vector associated with a first satellite of the plurality of satellites is established. A second inclination vector associated with a second satellite of the plurality of satellites is established. The first satellite and the second satellite are controlled, such that the first satellite and the second satellite are synchronized with a node.Type: GrantFiled: January 10, 2014Date of Patent: April 12, 2016Assignee: The Boeing CompanyInventor: Yiu-hung M. Ho
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Publication number: 20150197350Abstract: A first inclination vector associated with a first satellite of the plurality of satellites is established. A second inclination vector associated with a second satellite of the plurality of satellites is established. The first satellite and the second satellite are controlled, such that the first satellite and the second satellite are synchronized with a node.Type: ApplicationFiled: January 10, 2014Publication date: July 16, 2015Applicant: The Boeing CompanyInventor: Yiu-hung M. Ho
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Patent number: 8930048Abstract: The disclosed method involves calculating, with at least one processor, a desired orbit for the spacecraft. The method further involves calculating a velocity change required to achieve an orbit eccentricity, a velocity change required to achieve a semi-major axis, and a velocity change required to achieve an orbit inclination; all of which correspond to the desired orbit for the spacecraft. Also, the method involves calculating the direction of the vector sum of the velocity change required to achieve the orbit eccentricity, the velocity change required to achieve the semi-major axis, and the velocity change required to achieve the orbit inclination. Further, the method involves activating at least one propulsion device of the spacecraft in the direction of the vector sum in order to change the current orbit of the spacecraft to the desired orbit for the spacecraft, thereby changing the orbit eccentricity, the semi-major axis, and the orbit inclination simultaneously.Type: GrantFiled: October 23, 2012Date of Patent: January 6, 2015Assignee: The Boeing CompanyInventors: Fawwad M. Batla, Yiu-hung M. Ho
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Patent number: 8457810Abstract: A method and system for application of a compound steering law for efficient low thrust transfer orbit trajectory for a spacecraft are disclosed. The method involves calculating, with at least one processor, a desired orbit for the spacecraft. The method further involves calculating a velocity change required to achieve an orbit eccentricity and a velocity change required to achieve a semi-major axis, both of which correspond to the desired orbit for the spacecraft. Also, the method involves calculating the direction of the vector sum of the velocity change required to achieve the orbit eccentricity and the velocity change required to achieve the semi-major axis. Further, the method involves firing at least one thruster of the spacecraft in the direction of the vector sum in order to change the current orbit of the spacecraft to the desired orbit for the spacecraft, thereby changing the orbit eccentricity and the semi-major axis simultaneously.Type: GrantFiled: April 14, 2011Date of Patent: June 4, 2013Assignee: The Boeing CompanyInventors: Fawwad M. Batla, Yiu-Hung M. Ho
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Patent number: 8439312Abstract: The present system and methods enable simultaneous momentum dumping and orbit control of a spacecraft, such as a geostationary satellite. Control equations according to the present system and methods generate accurate station-keeping commands quickly and efficiently, reducing the number of maneuvers needed to maintain station and allowing station-keeping maneuvers to be performed with a single burn. Additional benefits include increased efficiency in propellant usage, and extension of the satellite's lifespan. The present system and methods also enable tighter orbit control, reduction in transients and number of station-keeping thrusters aboard the satellite. The present methods also eliminate the need for the thrusters to point through the center of mass of the satellite, which in turn reduces the need for dedicated station-keeping thrusters. The present methods also facilitate completely autonomous orbit control and angular momentum control using.Type: GrantFiled: June 18, 2008Date of Patent: May 14, 2013Assignee: The Boeing CompanyInventors: Yiu-Hung M. Ho, Jeffrey A. Kurland, David S. Uetrecht
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Patent number: 8282043Abstract: The present system and methods enable simultaneous momentum dumping and orbit control of a spacecraft, such as a geostationary satellite. Control equations according to the present system and methods generate accurate station-keeping commands quickly and efficiently, reducing the number of maneuvers needed to maintain station and allowing station-keeping maneuvers to be performed with a single burn. Additional benefits include increased efficiency in propellant usage, and extension of the satellite's lifespan. The present system and methods also enable tighter orbit control, reduction in transients and number of station-keeping thrusters aboard the satellite. The present methods also eliminate the need for the thrusters to point through the center of mass of the satellite, which in turn reduces the need for dedicated station-keeping thrusters. The present methods also facilitate completely autonomous orbit control and control using Attitude Control Systems (ACS).Type: GrantFiled: February 23, 2011Date of Patent: October 9, 2012Assignee: The Boeing CompanyInventor: Yiu-Hung M. Ho
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Patent number: 8205839Abstract: A method for performing east-west station keeping for a satellite in an inclined synchronous orbit is described. The method includes averaging a value of a right ascension of the ascending node for an inclination vector associated with the satellite over a period of the control cycle, and managing corrections for the satellite such that an eccentricity vector, directed at perigee, is substantially collinear with the inclination vector.Type: GrantFiled: November 6, 2006Date of Patent: June 26, 2012Assignee: The Boeing CompanyInventors: Bernard M. Anzel, Yiu-Hung M. Ho
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Publication number: 20110144835Abstract: The present system and methods enable simultaneous momentum dumping and orbit control of a spacecraft, such as a geostationary satellite. Control equations according to the present system and methods generate accurate station-keeping commands quickly and efficiently, reducing the number of maneuvers needed to maintain station and allowing station-keeping maneuvers to be performed with a single burn. Additional benefits include increased efficiency in propellant usage, and extension of the satellite's lifespan. The present system and methods also enable tighter orbit control, reduction in transients and number of station-keeping thrusters aboard the satellite. The present methods also eliminate the need for the thrusters to point through the center of mass of the satellite, which in turn reduces the need for dedicated station-keeping thrusters. The present methods also facilitate completely autonomous orbit control and control using Attitude Control Systems (ACS).Type: ApplicationFiled: February 23, 2011Publication date: June 16, 2011Applicant: THE BOEING COMPANYInventor: Yiu-Hung M. Ho
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Patent number: 7918420Abstract: The present system and methods enable simultaneous momentum dumping and orbit control of a spacecraft, such as a geostationary satellite. Control equations according to the present system and methods generate accurate station-keeping commands quickly and efficiently, reducing the number of maneuvers needed to maintain station and allowing station -keeping maneuvers to be performed with a single burn. Additional benefits include increased efficiency in propellant usage, and extension of the satellite's lifespan. The present system and methods also enable tighter orbit control, reduction in transients and number of station-keeping thrusters aboard the satellite. The present methods also eliminate the need for the thrusters to point through the center of mass of the satellite, which in turn reduces the need for dedicated station-keeping thrusters. The present methods also facilitate completely autonomous orbit control and control using Attitude Control Systems (ACS).Type: GrantFiled: July 17, 2007Date of Patent: April 5, 2011Assignee: The Boeing CompanyInventor: Yiu-Hung M. Ho
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Patent number: 7823836Abstract: A method and apparatus for maneuvering a satellite in orbit to alternately optimize the collection of solar energy and to take sensor data of terrestrial objects is disclosed The longitudinal axis of a large payload package is oriented perpendicular to the orbital plane to minimize the disturbance torque due to gravity gradient, and to allow simple rotation about the axis for attitude change between optimal Sun and optimal ground coverage.Type: GrantFiled: December 4, 2006Date of Patent: November 2, 2010Assignee: The Boeing CompanyInventors: Yiu-Hung M. Ho, John Y. Liu
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Publication number: 20090078829Abstract: The present system and methods enable simultaneous momentum dumping and orbit control of a spacecraft, such as a geostationary satellite. Control equations according to the present system and methods generate accurate station-keeping commands quickly and efficiently, reducing the number of maneuvers needed to maintain station and allowing station-keeping maneuvers to be performed with a single burn. Additional benefits include increased efficiency in propellant usage, and extension of the satellite's lifespan. The present system and methods also enable tighter orbit control, reduction in transients and number of station-keeping thrusters aboard the satellite. The present methods also eliminate the need for the thrusters to point through the center of mass of the satellite, which in turn reduces the need for dedicated station-keeping thrusters. The present methods also facilitate completely autonomous orbit control and angular momentum control using.Type: ApplicationFiled: June 18, 2008Publication date: March 26, 2009Inventors: Yiu-Hung M. Ho, Jeffrey A. Kurland, David S. Uetrecht
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Publication number: 20090020650Abstract: The present system and methods enable simultaneous momentum dumping and orbit control of a spacecraft, such as a geostationary satellite. Control equations according to the present system and methods generate accurate station-keeping commands quickly and efficiently, reducing the number of maneuvers needed to maintain station and allowing station-keeping maneuvers to be performed with a single burn. Additional benefits include increased efficiency in propellant usage, and extension of the satellite's lifespan. The present system and methods also enable tighter orbit control, reduction in transients and number of station-keeping thrusters aboard the satellite. The present methods also eliminate the need for the thrusters to point through the center of mass of the satellite, which in turn reduces the need for dedicated station-keeping thrusters. The present methods also facilitate completely autonomous orbit control and control using Attitude Control Systems (ACS).Type: ApplicationFiled: July 17, 2007Publication date: January 22, 2009Inventor: Yiu-Hung M. Ho
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Publication number: 20080128559Abstract: A method and apparatus for maneuvering a satellite in orbit to alternately optimize the collection of solar energy and to take sensor data of terrestrial objects is disclosed The longitudinal axis of a large payload package is oriented perpendicular to the orbital plane to minimize the disturbance torque due to gravity gradient, and to allow simple rotation about the axis for attitude change between optimal Sun and optimal ground coverage.Type: ApplicationFiled: December 4, 2006Publication date: June 5, 2008Inventors: Yiu-Hung M. Ho, John Y. Liu
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Publication number: 20080105788Abstract: A method for performing east-west station keeping for a satellite in an inclined synchronous orbit is described. The method includes averaging a value of a right ascension of the ascending node for an inclination vector associated with the satellite over a period of the control cycle, and managing corrections for the satellite such that an eccentricity vector, directed at perigee, is substantially collinear with the inclination vector.Type: ApplicationFiled: November 6, 2006Publication date: May 8, 2008Inventors: Bernard M. Anzel, Yiu-Hung M. Ho
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Patent number: 6015116Abstract: Satellite stationkeeping and momentum-dumping methods are facilitated by the use of diagonally-arranged thruster pairs which are positioned on a selected one of a nadir and an antinadir satellite face. A first one of the thruster pairs is directed so that its thruster forces are spaced by moment arms from the satellite's center of mass. Firings of this thruster pair are separated by a momentum-dumping right ascension difference that is chosen to enhance momentum authority. These firings generate momentum-dumping torques and contribute to stationkeeping velocity changes. A second one of the thruster pairs is directed so that its thruster forces substantially pass through the center of mass. Firings of this thruster pair are separated by a stationkeeping right ascension difference chosen to minimize fuel consumption while providing a major portion of stationkeeping velocity changes.Type: GrantFiled: December 11, 1997Date of Patent: January 18, 2000Assignee: Hughes Electronics CorporationInventors: Bernard M. Anzel, Yiu-Hung M. Ho, Richard A. Noyola