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:
Feb. 08, 1994
Filed:
Dec. 18, 1992
Jeremiah O Salvatore, Redondo Beach, CA (US);
John R Murphy, El Segundo, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A propellant immobilizing system and method in which propellant motion in the propellant storage tanks (22) is reduced or eliminated during velocity change maneuvers to reduce disturbance torques acting upon the spacecraft (10) and improving the spacecraft attitude pointing performance. The thrusters (14, 16, 18 or 20) are fired to produce a small impulse in the direction of the desired Velocity change to begin motion of the propellant within the fuel tank in the opposite direction. After the fuel has moved within the tank to a location in which the propellant center of mass is aligned with the propellant tank (22) center of curvature in the direction of the desired velocity change, thrusters (14, 16, 18 or 20) are again fired to produce a force in the direction of the current velocity of the propellant center of mass to stop the propellant center of mass relative to the propellant tank (22). With the center mass of the propellant now aligned with the propellant tank center of curvature in the direction of the desired velocity change, the thrusters (14, 16, 18 or 20) are again fired to produce the desired velocity change with the propellant center of mass now being trapped in the propellant tank such that additional motion of the propellant is inhibited. After completion of the maneuver, the propellant gradually migrates back to its original position due to the influence of a propellant management device within the propellant tank.