Due to the low cost and flexibility, the applications of low thrust and microprobes (e.g. CubeSats, NanoSats and their constellations) to space missions become popular. However, the time of flight incredibly increases. Therefore, during the multiple-revolution orbital transfer among mission orbits, the spacecraft (s/c) slowly crosses the regions that are probably in mean-motion resonances (MMR) with the central body, e.g. NASA’s DAWN s/c around Vesta, which gives rise to the possibility of being captured into MMR and consequently brings about strong perturbations on its motion. In order to reduce the capture risk and enhance mission robustness, this project firstly quantitatively estimates the probability of spacecraft’s capture into first-order MMR with a small body for the first time by exploiting the adiabatical invariant theory [1] that was developed in celestial mechanics to investigate the resonance capture phenomenon of solar system evolution. Then, the dependences of this probability on the resonant angle and orbital geometry (i.e. different combinations of orbital eccentricity and inclination of the s/c) are identified. And the sensitivities of the probability on the perturbations, the uncertain gravity of the small body and the uncertain maneuver accounting for both magnitude and direction are evaluated. Finally, to provide insights on transferring the captured s/c out of the MMR, potential maneuver strategies in terms of the thruster’s magnitude and direction are developed and optimized for minimum fuel consumption and transfer time due to the limited maneuver and operational capabilities. A software tool will be developed for systematical analysis. The methodologies and tools developed in this research can also be applied to characterize the orbital evolution of space debris, where its MMR with Earth also plays a significant role. [1] Henrard, J., Capture into resonance: an extension of the use of adiabatic invariants, Celestial Mechanics 27, 3-22, 1982.
