Fig. 1. Various levels of the Torino scale

Fig. 2. Schematic diagram of impacting an asteroid’s surface

Fig. 3. Schematic diagram of the COGs （blue） and BIPs （red） under different interception angles

Fig. 4. Thermodynamic diagrams of the velocity changes generated by each impact surface under three different attitudes when the interception angle is 5.22°

Fig. 5. Calculation process for a small celestial body kinetic energy impact mission

Fig. 6. Three-dimensional launch window of Apophis

Fig. 7. Projection of the launch window of Apophis on the deflection distance-launch date plane

Fig. 8. Projection of the launch window of Apophis on the impact date-launch date plane

Fig. 9. Best transfer orbit

Fig. 10. Frequency distribution of $\mathrm{\Delta }{\mathit{v}}_{\mathrm{A}\mathrm{p}\mathrm{o}\mathrm{p}\mathrm{h}\mathrm{i}\mathrm{s}}$ with 100 000 samples in the Apophis orbital coordinate （upper figures are for the BIP strategy， while lower ones are for the COG strategy）

Fig. 11. Distribution of the deflection distance with 100 000 samples