Patent ID: 6523785
Filing Date: 2003-02-25
Classification: B64G

Abstract:
An attitude control actuation system for spacecraft, which has means to actuate the attitude of the spacecraft and has means to desaturate the reaction wheels with the use of momentum exchange, which is within the closed system of the spacecraft, the apparatus comprising:a left reaction wheel, said left reaction wheel being in the form of a disk, a left reaction wheel actuator, said left reaction wheel actuator being rotationally coupled to said left reaction wheel about a left reaction wheel axis and further said left reaction wheel actuator having means to rotate said left reaction wheel about said left reaction wheel axis in both directions and further having means to stop the rotation of said left reaction wheel about said left reaction wheel axis and further having means to free spin said left reaction wheel about said left reaction wheel axis in both directions, a left gimbal, said left gimbal being larger than and disposed about said left reaction wheel and said left reaction wheel actuator and further being rotationally coupled to said left reaction wheel actuator about a left reaction wheel actuator axis, said left reaction wheel actuator axis being perpendicular to said left reaction wheel axis, two left reaction wheel actuator axis control units, said left reaction wheel actuator axis control units having means to rotate said left reaction wheel actuator about said left reaction wheel actuator axis in both directions and further having means to stop the rotation of said left reaction wheel actuator about said left reaction wheel actuator axis and further having means to free spin said left reaction wheel actuator about said left reaction wheel actuator axis in both directions, two left gimbal axis control units, said left gimbal axis control units having means to rotate said left gimbal about said left gimbal axis in both directions and further having means to stop the rotation of said left gimbal about said left gimbal axis and further having means to free spin said left gimbal about said left gimbal axis in both directions, a right reaction wheel, said right reaction wheel being in the form of a disk, a right reaction wheel actuator, said right reaction wheel actuator being rotationally coupled to said right reaction wheel about a right reaction wheel axis and further said right reaction wheel actuator having means to rotate said right reaction wheel about said right reaction wheel axis in both directions and further having means to stop the rotation of said right reaction wheel about said right reaction wheel axis and further having means to free spin said right reaction wheel about said right reaction wheel axis in both directions, a right gimbal, said right gimbal being larger than and disposed about said right reaction wheel and said right reaction wheel actuator and further being rotationally coupled to said right reaction wheel actuator about a right reaction wheel actuator axis, said right reaction wheel actuator axis being perpendicular to said right reaction wheel axis, two right reaction wheel actuator axis control units, said right reaction wheel actuator axis control units having means to rotate said right reaction wheel actuator about said right reaction wheel actuator axis in both directions and further having means to stop the rotation of said right reaction wheel actuator about said right reaction wheel actuator axis and further having means to free spin said right reaction wheel actuator about said right reaction wheel actuator axis in both directions, two right gimbal axis control units, said right gimbal axis control units having means to rotate said right gimbal about said right gimbal axis in both directions and further having means to stop the rotation of said right gimbal about said right gimbal axis and further having means to free spin said right gimbal about said right gimbal axis in both directions, a spacecraft, said spacecraft being larger than and disposed about said left gimbal and further being rotationally coupled to said left gimbal about a left gimbal axis, said left gimbal axis being perpendicular to said left reaction wheel actuator axis, also said spacecraft being larger than and disposed about said right gimbal and further being rotationally coupled to said right gimbal about a right gimbal axis, said right gimbal axis being perpendicular to said right reaction wheel actuator axis.