THE NEAR RADIO SCIENCE INVESTIGATIONS

The science objectives for the Near-Earth Asteroid Rendezvous (NEAR) R adio Science team include determining the masses of asteroids 253 Math ilde (to within 10%) and 433 Eros (<0.1%). While the NEAR spacecraft i s in orbit about Eros, the radiometric spacecraft tracking data, the o ptical landmark tracking data, and the lidar altimetry measurements wi ll be used to determine the gravity field of Eros. Comparisons of this gravity field with one determined from Eros shape models (assuming co nstant density) will provide constraints upon the internal structure o f this asteroid. In addition, the spin state, principal axes, and mome nts of inertia will be determined as part of the Radio Science activit ies. A campaign to meet the radio science objectives will require the close cooperation of the NEAR Navigation, Imaging, and Lidar teams.