Determination of eros physical parameters for near earth asteroid rendezvous orbit phase navigation

摘要

Navigation of the orbit phase of the Near Earth Asteroid Rendezvous (NEAR) mission will require determination of certain physical parameters describing the size, shape, gravity field, attitude and inertial properties of (433) Eros. Prior to launch, little was known about Eros except for its orbit and spin rate, which could be determined with high precision from ground based telescope observations. Radar bounce and light curve data provided a rough estiamte of Eros shape and a fairly good estimate of the pole and prime meridian. The determination of the NeAR spacecraft orbitrequires a high precision model of Eros' physical parameters and the ground based data provides only marginal a priari information. The initial orbit determination strategy is therefore concerned with developing a precise model of Eros.