Dynamics and control of a solar collector system for near Earth object deflection

A solar collector system is a possible method using solar energy to deflect Earth-threatening near-Earth objects.We investigate the dynamics and control of a solar collector system including a main collector （MC） and secondary collector （SC）.The MC is used to collect the sunlight to its focal point,where the SC is placed and directs the collected light to an asteroid.Both the relative position and attitude of the two collectors should be accurately controlled to achieve the desired optical path.First,the dynamical equation of the relative motion of the two collectors in the vicinity of the asteroid is modeled.Secondly,the nonlinear sliding-mode method is employed to design a control law to achieve the desired configuration of the two collectors.Finally,the deflection capability of this solar collector system is compared with those of the gravitational tractor and solar sail gravitational tractor.The results show that the solar collector is much more efficient with respect to deflection capability.