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Estimation of Gravitation Parameters of Saturnian Moons Using Cassini Attitude Control Flight DataA major science objective of the Cassini mission is to study Saturnian satellites. The gravitational properties of each Saturnian moon is of interest not only to scientists but also to attitude control engineers. When the Cassini spacecraft flies close to a moon, a gravity gradient torque is exerted on the spacecraft due to the mass of the moon. The gravity gradient torque will alter the spin rates of the reaction wheels (RWA). The change of each reaction wheel's spin rate might lead to overspeed issues or operating the wheel bearings in an undesirable boundary lubrication condition. Hence, it is imperative to understand how the gravity gradient torque caused by a moon will affect the reaction wheels in order to protect the health of the hardware. The attitude control telemetry from low-altitude flybys of Saturn's moons can be used to estimate the gravitational parameter of the moon or the distance between the centers of mass of Cassini and the moon. Flight data from several low altitude flybys of three Saturnian moons, Dione, Rhea, and Enceladus, were used to estimate the gravitational parameters of these moons. Results are compared with values given in the literature.
Document ID
20150007834
Document Type
Conference Paper
External Source(s)
Authors
Krening, Samantha C. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
May 11, 2015
Publication Date
August 19, 2013
Subject Category
Space Sciences (General)
Meeting Information
2013 AIAA Guidance, Navigation, and Control Conference(Boston, MA)
Distribution Limits
Public
Copyright
Other
Keywords
angular momentum
reaction wheel
gravitational parameter
Enceladus
gravity gradient torque
attitude control
Dione
Rhea