Optimal flights to near-earth asteroid for impact-kinetic influence

The possibility to prevent the asteroid's collision with the Earth by means of an impact-kinetic influence of the spacecraft on the asteroid is studied. The spacecraft optimal flights to the near-Earth asteroid in order to give the impact influence on the asteroid and correct its orbit are analysed. First, the flights with a high thrust engine are studied in the impulse approach. Then the flights with the chemical and electric-jet engines are analysed. The high thrust is used to escape from the geocentric orbit, and the low thrust is applied for heliocentric motion. The spacecraft optimal flight trajectories maximizing the asteroid deflection from the Earth are determined. The numerical results are given for the asteroid Toutatis orbit. The possibility to prevent the Earth collision with the not very large asteroids (of radius up to 60-270m) by means of the modern rocket-space systems is shown.