X-ray communication based on X-ray spectrum modulation information is a novel communication method, which can effectively improve communication ability and anti-interference ability. In this paper, four characteristic X-rays are chosen to modulate information. The influence of channel attenuation, random noise in space, and miss-shooting rate caused by adjacent targets are discussed. Based on error-correcting output codes and a 10-fold cross-validation method, a neural network intelligent classifier is designed to realize intelligent information demodulation. Simulation results show that if the miss-shooting rate is lower than 0.4 and the photon retention rate after channel attenuation is higher than 0.0008, then the classifier can achieve a recognition success rate of more than 99%. This study provides reliable index requirements for the performance of the four-target material source equipment to be designed next. This paper also provides a theoretical basis for the subsequent further realization of space communication capabilities.

Near-Earth asteroids pose an enormous threat to Earth. Removing them effectively from risk orbits is a crucial issue. To improve the deflection efficiency, we propose a method to control an intermediate asteroid as a gravity tractor to change the orbit of potentially hazardous asteroid. A multiple kinetic impact method is applied to an intermediate asteroid to change its orbit toward the potentially hazardous asteroid. The goal of multiple kinetic impacts is to control the intermediate asteroid to form a gravity tractor system with the potentially hazardous asteroid. First, we chose an asteroid that requires smaller transfer velocity increments as an intermediate asteroid. Then, we design the orbit of the gravity tractor system and use a multi-objective harris hawk optimization algorithm to optimize the kinetic impact mission. Finally, the effects of direct transfer model, multi-pulse transfer model, and gravity assist transfer model are investigated respectively. We compare the three transfer models and obtain a suitable kinetic impact deflection scheme. The results show that the proposed method can effectively deflect the potentially hazardous asteroid. Using an asteroid as a gravity tractor can greatly increase the deflection distance. Deflection distances can be increased from hundreds of kilometers to fractions of an AU.