NASA NTRS1995
The Near Earth Asteroid Rendezvous (NEAR) mission spacecraft will arrive at Asteroid 433 (Eros) in February 1999. Following an initial period of characterization, the science phase of the mission will commence, and unprecedented information concerning an asteroid's shape, mass, density, composition, and rotational dynamics will be sent to Earth for analysis. It will also mark the start of orbital operations about the most complex and irregular gravity field ever encountered in the history of space exploration. The severity of Eros' distortion from the usual spheroid bodies encountered in planetary exploration leads to fundamental differences in the orbital dynamics about it. Operations about Eros will also serve as an exciting test of orbital determination and prediction in an orbital environment which can be chaotic in some instances. General orbital dynamics about Eros are discussed. Some simple formulae are given for the secular motion of the node and argument of periapsis. Conditions for a satellite orbit to escape from Eros are discussed, and some simple results derived. Finally, the chaotic nature of certain orbits about Eros are discussed, and the consequences for orbit prediction are investigated.