The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 04, 1991
Filed:
Sep. 29, 1989
Bernard M Anzel, Venice, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
An improved method for satellite station keeping is disclosed. The method provides for station keeping of a three axis stabilized satellite 10 using only two thrusters 20 and 22. The thrusters 20 and 22 can be ion or liquid propulsion thrusters and are mounted on the anti-nadir face 18 of the satellite 10. The north thruster 20 is canted at an angle .THETA. from the north-south axis 16 of the satellite 10 in a northern direction and the south thruster 22 is canted at the angle .THETA. from the north-south axis 16 in a southern direction. Both thrusters 20 and 22 are also translated to the east or west along an east-west axis 14 of the satellite 10 and swiveled at variable angles .alpha..sub.1 and .alpha..sub.2 respectively. A specific teaching of the invention discloses techniques for determining the angles .alpha..sub.1 and .alpha..sub.2 and the firing positions for the thrusters 20 and 22 to maintain the satellite 10 in a stationary orbit. In a specific embodiment, a backup thruster 24 is provided to counter the radial acceleration buildup from a failure of one of the thrusters 20 or 22. Also, in a specific embodiment, first and second slide mechanisms are provided to translate the first and second thrusters 20 and 22 to the east or west along the east-west axis 14 of the satellite 10 for a change in the angles .alpha..sub.1 or .alpha..sub.2 in order to maintain the lines of thrust from the thrust of the thrusters 20 and 22 respectively through the center-of-gravity of the satellite 10.