LAUSR

Abstract This paper investigates the characteristics of lift-off velocity with analytically derived vector expression. Compared with a single asteroid system, there is an external perturbed body that has influence on the dynamic environment of the target body surface for a binary asteroid system. Binary asteroid systems modeled by ellipsoid-sphere model are classified as two cases: synchronous system and non-synchronous system. The effects of different factors on the lift-off velocity related with the dynamic characteristics of the systems are analyzed. In the synchronous system, the lift-off velocity curves are similar with those in the single asteroid system. The maximum relative difference in lift-off velocity caused by perturbed bodies of different masses is less than 8%, according to maximum and minimum lift-off velocity distributions. The density/spin parameter and ellipticity parameter have other different influences on lift-off velocity. As for a non-synchronous system, the distributions of the maximum and minimum lift-off velocity with different poses are studied and their trends for one period are summarized. The minimum lift-off velocity is found to be close to zero in the low latitude at some certain time points that are affected by the spin ratio.