HR: 1330h
AN: P12A-1053    [PDF]
TI: Tidal deformation, Orbital Dynamics and JIMO
AU: * Ratcliff, J T
EM: Todd.Ratcliff@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91104-8099 United States
AU: Wu, X
EM: Xiaoping.Wu@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91104-8099 United States
AU: Williams, J G
EM: James.G.Williams@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91104-8099 United States
AB: Observations of Europa, Ganymede and Callisto obtained from encounters by the Galileo spacecraft strongly suggest the possibility of liquid oceans under the icy shells of these Jovian satellites. The strong tidal environments in which these moons are found and the fact that a planetary body with internal fluid undergoes greater deformation than an otherwise solid body make a compelling case for using tidal observations as a method for ocean detection. Given the high degree of uncertainty in our knowledge of the interiors of these moons, a comprehensive geodetic program measuring different physical signatures related to tidal deformation and interior structure is preferred to using separate and various interior parameters that may not be as closely tied to actual measurable quantities. Potential and displacement tidal Love numbers, libration amplitudes of the surface ice shell and rocky mantle, static topography and gravity fields and other quantities should all be included in the measurement objectives. Many geodetic techniques rely heavily upon orbital positions of the spacecraft. Their accurate determination depend on factors such as the orbital configuration, the gravity fields of the icy moons, as well as the duration and geometry of tracking. Given the competing science, engineering and planetary protection demands, orbital accuracy subject to constraints has become a critical mission design issue. Orbit determination simulations and covariance analyses will be used to investigate the achievable accuracies of spacecraft position and geodetic signatures under different orbital and tracking scenarios.
DE: 1227 Planetary geodesy and gravity (5420, 5714, 6019)
DE: 5450 Orbital and rotational dynamics
DE: 5744 Orbital and rotational dynamics
DE: 5770 Tidal forces
DE: 6218 Jovian satellites
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting